U.S. patent application number 14/134153 was filed with the patent office on 2015-04-30 for internet switch box, system and method for internet telephony.
This patent application is currently assigned to Sony Corporation. The applicant listed for this patent is Faramarz VAZIRI, John D. Wimsatt. Invention is credited to Faramarz VAZIRI, John D. Wimsatt.
Application Number | 20150117443 14/134153 |
Document ID | / |
Family ID | 25203140 |
Filed Date | 2015-04-30 |
United States Patent
Application |
20150117443 |
Kind Code |
A1 |
VAZIRI; Faramarz ; et
al. |
April 30, 2015 |
INTERNET SWITCH BOX, SYSTEM AND METHOD FOR INTERNET TELEPHONY
Abstract
An Internet switch box connects between a telephone set and a
public switched telephone network (PSTN) line, the latter of which
is used both for PSTN telephone conversations and for connection to
an Internet service provider (ISP). The switch box contains
hardware and embedded software for establishing a connection to an
ISP and for Internet telephony. When two users, each having an
Internet switch box connected to the telephone set, wish to have an
Internet telephony conversation, one calls the other over the PSTN.
When they agree to an Internet telephony conversation, they signal
their Internet switch boxes, by pressing either buttons on the
switch boxes or certain keys on the telephone keypads, to switch to
Internet telephony. The switch boxes disconnect the PSTN call and
connect to their ISPs. Once the switch boxes are on the Internet,
they contact each other through a server which supplies Internet
protocol (IP) addresses of switch boxes, and the users continue
their conversation by Internet telephony. The users can also
prearrange to call each other solely by Internet telephony, in
which case they do not need to talk to each other over the
PSTN.
Inventors: |
VAZIRI; Faramarz; (Hopewell
Junction, NY) ; Wimsatt; John D.; (Washington,
DC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
VAZIRI; Faramarz
Wimsatt; John D. |
Hopewell Junction
Washington |
NY
DC |
US
US |
|
|
Assignee: |
Sony Corporation
Tokyo
JP
|
Family ID: |
25203140 |
Appl. No.: |
14/134153 |
Filed: |
December 19, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12208577 |
Sep 11, 2008 |
RE44716 |
|
|
14134153 |
|
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Current U.S.
Class: |
370/352 |
Current CPC
Class: |
H04L 65/102 20130101;
H04L 65/1069 20130101; H04M 7/0069 20130101; H04M 7/122 20130101;
H04M 2215/46 20130101; H04M 15/55 20130101; H04M 15/49 20130101;
H04M 2215/0176 20130101; H04M 3/428 20130101; H04M 3/4938 20130101;
H04M 3/5307 20130101; H04M 2215/54 20130101; H04L 2012/6443
20130101; H04M 3/537 20130101; H04M 15/56 20130101; H04M 15/51
20130101; H04M 3/533 20130101; H04M 2215/44 20130101; H04M 7/0057
20130101; H04L 2012/6429 20130101; H04L 2012/6475 20130101; H04Q
3/72 20130101; H04L 2012/6486 20130101; H04L 12/6418 20130101; H04L
12/5692 20130101; H04M 3/567 20130101; H04L 2012/6481 20130101;
H04M 1/2535 20130101; H04L 29/06 20130101; H04M 2215/0168 20130101;
H04L 2012/6472 20130101; H04M 2215/202 20130101 |
Class at
Publication: |
370/352 |
International
Class: |
H04L 29/06 20060101
H04L029/06 |
Claims
1-52. (canceled)
53. A method for connecting a first communication apparatus with a
second communication apparatus, comprising: providing a first
address of the first communication apparatus to the second
communication apparatus over a secondary network, the first
communication apparatus communicating over a primary network as a
first connection; and establishing a second connection between the
first communication apparatus and the second communication
apparatus over the secondary network using the first address.
54. The method of claim 53 further comprising: communicating, via
the second connection, information between the first communication
apparatus and the second communication apparatus.
55. The method of claim 53 further comprising: disconnecting at
least one of the first communication apparatus and the second
communication apparatus from the primary network after the second
connection is established.
56. The method of claim 53 further comprising: disabling the first
connection after the second connection is established.
57. The method of claim 53 further comprising: providing a second
address of the second communication apparatus over the secondary
network, wherein the second connection is established using at
least one of the first address and the second address.
58. The method of claim 53 further comprising: providing a second
address of the second communication apparatus over the secondary
network, wherein the second connection is established using the
first address and the second address.
59. The method of claim 53, wherein the first communication
apparatus is a telephone terminal.
60. The method of claim 53, wherein the second communication
apparatus is an internet server.
61. The method of claim 53, wherein the first address of the first
communication apparatus includes identification information.
62. A communication apparatus comprising: processing circuitry
configured to: provide a first address of a first communication
apparatus to a second communication apparatus over a secondary
network, the first communication apparatus communicating over a
primary network as a first connection; and communicate with the
second communication apparatus over the second network via a second
connection, the second connection being established using the first
address.
63. The apparatus of claim 62, the processing circuitry being
further configured to: disconnect the first communication apparatus
from the primary network after the second connection is
established.
64. The apparatus of claim 62, the processing circuitry being
further configured to: disable the first connection after the
second connection is established.
65. The apparatus of claim 62, the processing circuitry being
further configured to: receive a second address of the second
communication apparatus over the secondary network; and transmit
the first address of the first communication apparatus over the
secondary network.
66. The apparatus of claim 65, wherein the second connection is
established using the first address and the second address.
67. A communication apparatus comprising: processing circuitry
configured to: receive a first address of a first communication
apparatus over a second network, the first communication apparatus
communicating over a primary network as a first connection; and
establish communication with the first communication apparatus over
the second network via a second connection, the second connection
being established using the first address.
68. The apparatus of claim 67, wherein the first address is
received from the first communication apparatus.
69. The apparatus of claim 67, the processing circuitry being
further configured to: disconnect the second communication
apparatus from the primary network after the second connection is
established.
70. The apparatus of claim 67, the processing circuitry being
further configured to: disable the first connection after the
second connection is established.
71. The apparatus of claim 67, the processing circuitry being
further configured to: receive the first address of the first
communication apparatus over the secondary network; and transmit a
second address of the second communication apparatus over the
secondary network.
72. The apparatus of claim 67, wherein the second connection is
established using the first address and the second address.
73. A method for communicating with an apparatus comprising:
providing, via processing circuitry, a first address of a first
communication apparatus to a second communication apparatus over a
secondary network, the first communication apparatus communicating
over a primary network as a first connection; and communicating,
via the processing circuitry, with the second communication
apparatus over the second network via a second connection, the
second connection being established using the first address.
74. A method for communicating with an apparatus comprising:
receiving, via processing circuitry, a first address of a first
communication apparatus over a second network, the first
communication apparatus communicating over a primary network as a
first connection; and establishing, via the processing circuitry,
communication with the first communication apparatus over the
second network via a second connection, the second connection being
established using the first address.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuation-in-part of U.S. patent application
Ser. No. 08/810,148, filed Feb. 25, 1997, whose disclosure is
hereby incorporated by reference in its entirety into the present
disclosure.
FIELD OF THE INVENTION
[0002] The present invention relates to Internet telephony, i.e.,
placing telephone calls over a specific secondary network, such as
the Internet, by way of a standard telephone connection using the
Public Switched Telephone Network (PSTN).
DESCRIPTION OF RELATED ART
[0003] The technique of using the Internet to carry on telephone
communications is commonly referred to as Internet Telephony (IT)
or, sometimes, Voice on the Net (VON). IT is a way to communicate
over the Internet that bypasses PSTN toll connections. IT can be
advantageous for individuals and businesses that need or want to
communicate extensively with others outside of their local calling
areas, especially to frequently called numbers.
[0004] IT is typically accomplished by what is commonly referred to
as Personal Computer-Based Internet Telephony (PCIT). PCIT allows
users with properly equipped personal computers to complete long
distance telephone calls to one another over the Internet without
incurring a toll charge. To do so, the users must have personal
computers that are multimedia capable in terms of possessing a
sound card, sufficient processing power, a high quality microphone,
an adequate modem (preferably 14.4 or faster) and the same
specialized software programs, as well as an account with an online
service or Internet service provider (ISP) for connection to the
Internet via SLIP (the serial-line Internet protocol) or PPP (the
point-to-point protocol). Current PCIT techniques are not
compatible with shell accounts, which are accounts in which a user
logs on through terminal emulation to a remote machine running Unix
or the like and accesses the Internet through that remote machine
in text mode by typing commands at a prompt.
[0005] Several PCIT software packages are on the market. These
packages are mutually incompatible; two users wishing to make a
PCIT connection must have the same software package. Popular PCT
software packages include those marketed under the names "Iphone"
and "Web Phone."
[0006] The "Web Phone" software works in the following manner. The
users wishing to speak to each other must both be online for the
communication to take place, although they can arrange beforehand
to be online at the same time.
[0007] Both users run the software, and the software packages on
both computers seek each other by referring to each other's
Internet protocol (IP) addresses. An IP address can be static,
meaning that each user is assigned a single permanent IP address,
or dynamic, meaning that a user is assigned a different IP address
every time that user logs on. If the users both have static
Internet protocol addresses, they can simply store each other's IP
addresses beforehand. However, many users, including virtually all
users of less expensive ISP's and of online services such as
America Online, have dynamic IP addresses. Therefore, before the
users can connect to each other, they must log onto a common server
so that each one can find out the dynamic IP address which has been
assigned to the other user. Either way, once the users have each
other's IP addresses, the software packages can communicate with
each other over TCP/IP (transfer control protocol/Internet
protocol) ports 21845, 21846 and 21847.
[0008] Sound originating on one end is digitized via the microphone
and sound card, compressed, and transmitted to the other end as
packets over the Internet using TCP/IP, where the packets are
decompressed and converted back into sound via the sound card and
speakers.
[0009] There are, however, disadvantages associated with the
present state of IT or VON. Besides the hardware requirements and
the difficulty that many users have with configuring their
computers to achieve SLIP or PPP connections to their ISPs, until
such time as PCIT vendors can agree on standards, the requirement
that both users have the same software to communicate with each
other will remain. Not only is the hardware described above
expensive, but extensive knowledge of computers and the Internet is
also required, making IT intimidating to a majority of the
population who would otherwise like to take advantage of this
capability. Them are other disadvantages to PCIT. Its users need to
prearrange a time to call each other because both parties must take
proactive measures to connect the call and thereby converse with
each other.
[0010] Internet Telephony also sometimes refers to a new service
being planned whereby individuals or businesses may use or
pre-subscribe to a special access number and place their long
distance telephone calls by way of a long distance carrier who uses
the Intent to carry the calls. This service eliminates most of the
disadvantages of PCIT, but also eliminates most of the advantages,
in that toll and/or usage type charges still apply.
[0011] Devices are known for allowing PCIT by letting users
initiate a conversation over the PSTN and switching to IT. Such
devices exchange information relating to their IP addresses during
the PSTN phase of the call so that the IT phase of the call can be
completed. However, in such devices, the modem may be set or
initialized twice, once for the PSTN phase of the call to exchange
the IP address information and once for the IT phase of the call to
connect to the Internet. Setting the modems twice is
time-consuming. Also, such devices cannot be used for calls which
take place entirely by way of IT, since they have no way of
exchanging the IP address related information to locate each
other.
SUMMARY OF THE INVENTION
[0012] It is an object of the invention to allow a user to make
telephone calls via the Internet without a need for an expensive
multimedia-capable personal computer.
[0013] It is another object of the invention to allow a user to
make telephone calls via the Internet without a need to configure
such a computer for a SLIP or PPP connection to the Internet.
[0014] It is a further object of the invention to allow a user to
select a route for a telephone call (the Internet, the conventional
PSTN, a dedicated network, etc.) and to use a single device for the
call regardless of which route is selected.
[0015] It is a further object of the invention to provide a device
and method for Internet telephony which are easy to use, do not
require a computer and offer superb voice quality.
[0016] To these and other ends, the present invention is directed
to a terminal device or Internet switch box (ISB) for connecting a
first telephone set and a second telephone set over a selected one
of a primary network and a secondary network, the switch box
comprising: primary network connecting means for connecting the
first telephone set to the primary network; secondary network
connecting means for connecting the first telephone set to the
secondary network and for establishing a connection over the
secondary network between the first telephone set and the second
telephone set; relay means for (i) connecting, when the relay means
is in a first state, the first telephone set to the primary network
connecting means and for (ii) connecting, when the relay means is
in a second state, the first telephone set to the secondary network
connecting means; and switching means for receiving a switch-over
command to switch from the primary network to the secondary network
and for controlling, in response to the switch-over command, (i)
the relay means to disconnect the first telephone set from the
primary network connecting means and to connect the first telephone
set to the secondary network connecting means and (ii) the
secondary network connecting means to establish the connection over
the secondary network between the first telephone set and the
second telephone set.
[0017] A relatively inexpensive interface device, referred to as an
Internet switch box (ISB), is connected to or integrated within the
telephone. While the user must possess access to the Internet
either directly or via an Internet Service Provider (ISP) in order
to use the ISB, the user will not be subject to toll charges other
than those incurred using the PSTN to establish the Internet
telephone call. The user does not need to understand how a computer
works or how to use any PCIT software, since the ISB can be
preprogrammed to dial an ISP and to connect via.
[0018] SLIP or PPP. The user need only know how to dial the call
using normal PSTN dialing procedures and then simply switch the
call to an Internet connection, if available and desirable. Other
than the user pressing a button (either on the ISB or telephone
keypad) to initiate the Internet telephone call, the ISB takes care
of all connection procedures (i.e., handshaking) necessary to set
up and maintain the Internet telephone call. While both parties
must possess an ISB in order to take advantage of the ISB's IT
capabilities, only one party needs to initiate the telephone call
in order to establish the Internet connection, so that
prearrangement is not required.
[0019] Advantageously, the selection among networks may be among
the PSTN, selected proprietary networks, or the Internet. It should
be noted that the PSTN utilizes circuit switching techniques
whereas, for instance, the Internet makes use of packet switching.
Circuit switching was specifically designed and is best for analog
voice transmissions, whereas packet switching was designed and is
best for digital data transmissions. Regardless, either type of
switching may be employed for voice or data. The calling party uses
the PSTN to first establish the connection between calling and
called parties, and then the two parties decide whether or not to
use their ISB's to re-establish the connection via a secondary
network such as the Internet. The users will consider convenience,
cost and connection quality in making this choice. If the telephone
call is to another party in the same local calling area, of short
duration, or one where, regardless of cost, the stability and voice
quality of the connection are essential, then the users typically
opt to stay on the PSTN connection and not seek to switch to the
Internet. Otherwise, the potential cost savings of simply switching
to an Internet connection make doing so preferable.
[0020] As indicated, an ISB may be incorporated into a telephone or
be a standalone adjunct device connected between the telephone and
the telephone line. Additionally, ISB's may be associated with
facsimile machines, wireless telephones and multiple line telephone
systems, such as key telephone and Private Branch Exchange (PBX)
systems, and operate to provide multiple users of such Customer
Provided Equipment (CPE) the ability to designate the secondary
network handling of their toll calls. According to one embodiment,
the ISB will set up a secondary network or Internet telephone call
after the PSTN connection has been established and in response to a
command to do so by its user(s) as described above. In an
alternative embodiment, the ISB may be configured to establish a
connection over a secondary network automatically unless commanded
not to prior to the call being placed. In either case the called
telephone can answer or simply ring before the telephone call can
be switched to a secondary network or the Internet. As such, the
ISB does not interfere with accepted and customary PSTN procedures
in that the PSTN portion of the telephone call is billable only if
there is an answer by a live person or an answering machine or
voice mail service.
[0021] In order to establish a secondary network or Internet
connection via the ISB, the user will first dial the PSTN telephone
number of the intended call recipient. Once the called telephone is
answered, which is a billable PSTN telephone call of short
duration, both parties initiate, via a simple key stroke, the
switch to the secondary network. The two ISB's disconnect the PSTN
call, and each initiates its own call to the other via the
secondary network. If the secondary network is the Internet, the
connection typically is by way of an Internet Service Provider
(ISP) which can be reached, advantageously, by a toll-free
telephone call enabling access to the user's Internet service
account which, advantageously, has unlimited use or use charges in
an amount much lower than the expected PSTN charges. The two ISB's
possess information (i.e., addresses, passwords, etc.) necessary to
re-connect the telephone call via the secondary network. Each ISB
can be programmed to provide call progress tones or to play
pre-recorded messages, music, etc., while the users await
reconnection. If the call cannot be connected via the secondary
network due to access problems at the ISP or otherwise, then each
party is so informed by a recognizable audio signal such as a busy
signal or a voice recording. Either or both parties can, by
pressing appropriate keys, retry their connection via the Internet
or reconnect the telephone call over the PSTN. This capability is
somewhat analogous to the redial capability on many conventional
telephones. Should two parties seek to avoid PSTN charges
altogether, they may use this same capability to do so via
prearrangement. In so doing, each party need only input the other
party's telephone number in addition to pressing the appropriate
buttons on the ISB or telephone keypad. Regardless, once the call
is connected via the secondary network or the Internet, the parties
terminate the call by hanging up, as with any PSTN call.
[0022] The present invention thus implements an embedded approach
to IT which offers the following advantages. The use of ISB's
allows low-cost, easy-to-use, embedded Internet access for
telephones. Lower cost is achieved because no PC's are required.
Users, many of whom would prefer not to have to configure a PC for
Internet access, are offered a familiar PSTN approach which can
identify a called party by that party's existing telephone number.
This approach also preserves the major advantage of IT, namely, the
use of low-cost Internet bandwidth.
[0023] While the invention is intended primarily for use with
single-line analog telephone sets, it can be adapted for use with
other telephone systems, such as DID PBX (direct-in-dial private
branch exchange) and Centrex service and with analog or digital
mobile telephones such as cellular telephones and PCS (personal
communication service) telephones. Also, while the ISB can be built
to access the ISP through a dial-up connection, it can
alternatively be built to access the ISP through another
connection, such as an ISDN (integrated services digital network)
connection or a cable modem connection.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The preferred embodiment will now be described in detail
with reference to the drawings, in which:
[0025] FIG. 1 is a flow chart depicting the functional organization
of the ISB;
[0026] FIG. 2 is a block diagram of an embodiment of the ISB;
[0027] FIG. 2A shows a software architecture implemented in the
hardware of FIG. 2;
[0028] FIG. 2B shows an alternative design of an ISB;
[0029] FIG. 3 shows a front panel view of the ISB;
[0030] FIG. 4 shows a rear panel view of the ISB;
[0031] FIG. 5 shows a flow chart of the steps involved in placing a
call between two ISB users;
[0032] FIG. 6 shows a flow chart of operations performed by one of
the ISB's during the call of FIG. 5;
[0033] FIGS. 7A-7E show the connections between one or more ISB's
and other telephony components during various calling
operations;
[0034] FIG. 8 shows a flow chart of the operational states assumed
by the ISB's during a PSTN-to-Internet call;
[0035] FIG. 8A shows a flow chart of the dynamic adjustment
performed during the Internet phase of a telephone call;
[0036] FIG. 9 shows a connection between an ISB and a help
desk;
[0037] FIG. 9A shows a flow chart of operation of an ISBSS, which
is a server used to complete calls;
[0038] FIGS. 10A and 10B show a code listing for the ISBSS;
[0039] FIG. 11 shows a state diagram of the ISBSS;
[0040] FIGS. 11A-11E show data structures exchanged between the
ISBSS and an ISB;
[0041] FIG. 11F shows an output of a monitoring process performed
by the ISBSS;
[0042] FIG. 11G shows an error log kept by the ISBSS;
[0043] FIG. 12 shows a system defined by multiple users' ISB's, the
PSTN, the Internet, the help desk, the ISBSS and various other
servers; and
[0044] FIG. 13 shows an IT standard which may be implemented with
the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0045] According to a preferred embodiment, the ISB is capable of
performing three major tasks: (1) establishing voice telephone
calls via the Internet; (2) sending/receiving voice messages via
Internet based E-Mail; and (3) interfacing with Internet Audio
Servers.
[0046] During the execution of each task, one of the following five
modes of operation can be assumed by the ISB: [0047] I. Programming
Mode: The ISB can be programmed locally or remotely by a telephone
keyset or external keyboard for its desired operation. [0048] II.
PSTN Voice Mode: The ISB is transparent and does not interfere with
voice communications between two parties involved. [0049] III. PSTN
Data Mode: The ISBs can exchange data via in-band signaling or
otherwise, [0050] IV. Internet Voice Mode: UDP packets are
exchanged to carry voice over the Internet ("UDP" stands for "User
Datagram Protocol," a protocol which allows applications to send
messages to one another). [0051] V. Internet Data Mode: TCP or UDP
packets are exchanged to carry information other than voice, such
as signaling or IP address resolution.
[0052] These modes of operation are realized by invoking a
collection of resources in the ISB 100 which are under control of
the ISB's application module 101. These resources are shown in FIG.
1 and described below:
[0053] Telephone Set Controller CSC) 102 is a module which controls
all signaling activities related to a "Plain Old Telephone" (POT),
i.e., on-hook, off-hook, hook-flash, pulse or tone dialing,
ringing, ringing trip detection, etc.
[0054] Loop/Start (US) Line Controller (LLC) 103 is a module which
controls all signaling related to a loop start telephone line,
i.e., ring detection, line seizure, hold, loop current detection,
pulse and tone dialing, etc.
[0055] Modem/Facsimile Module (MFM) 104 is a module which provides
a modem and facsimile engine to transmit digital data over PSTN
line. The baud rates of the modem/fax are determined by data
exchange requirements.
[0056] Voice Compander (=compresser and expander) Module (VCM) 105
is a module which compresses the linearly sampled voice into low
bit rate digital voice suitable for digital telephone applications.
The expander part of the module performs the reverse operation.
[0057] Tone Generators and Decoders (TGD) 106 is a module which
produces and detects all call progress (e.g., dial, busy, special,
etc.) and signaling (e.g., dual-tone multifrequency or DTMF,
multifrequency or MF, etc.) tones.
[0058] Voice Players and Recorders (VPR) 107 is a module which
records and plays voice prompts under the direction of the ISB.
[0059] Digital Switching Matrix (DSM) 108 is a module which enables
the different modules (i.e., TSC, LCC, TGD, VPR, etc.) can be
connected together via buses 111 and 112.
[0060] Signal Processing Services (SPS) 109 is a module which
handles signal processing services such as echo cancellation,
speech recognition, pitch adjustment, etc.
[0061] Network Connection Module (NCM) 110 is a module which
handles all digital networking communication between the ISB and
other external digital sources such as the ISP, another ISB,
various Internet resources and servers, etc. are handled by this
module.
[0062] Application Module (AM) 101 is a module which provides the
logic flow required to execute the above mentioned tasks.
[0063] The following describes several of the operations of the
ISB:
[0064] 1. Programming the ISB: The user uses the telephone keypad
and menu button 301 on front panel 302 of the ISB (FIG. 3) to enter
the programming mode (local or remote). The ISB guides the user
through a menu-driven procedure to program the ISB by using voice
prompts, guide tones or both. The user inputs the desired
information by entering a code with the telephone keypad
corresponding to each character to be entered; the instruction
manual for the ISB can include a table of two-digit codes for all
digits, all capital letters, all small letters (thus allowing
case-sensitive information to be entered with ease and accuracy),
and any punctuation marks to be used. The ISB can be programmed
externally (remotely) as well; external programming can be used to
input user-specific data and to update the ISB. Local programming
is especially useful when the user changes ISPs.
[0065] Programming can also be accomplished by connecting the ISB
to a computer such as an IBM-compatible PC via a serial link or
another appropriate link. The programming can be done by entering
ASCII commands from the PC through a standard terminal-emulation
program or by software written specifically for this purpose.
During manufacture, the ISB is programmed with its factory settings
through a connection to a computer.
[0066] 2. Telephone call: The calling party picks up the telephone
(goes off-hook) and dials the telephone number of the called party.
The ISB monitors and stores the digits dialed. The called telephone
rings and is answered by a live person, answering machine or voice
mail service. If the called telephone is answered by a live person,
the two parties decide whether or not it is appropriate to switch
to the Internet. The parties may initiate the switch to the
Internet by pressing the appropriate code on the telephone keypad
or Internet button 303 in the ISB itself. The ISBs of the calling
and called parties then disconnect the PSTN connection (this step
is not necessary if the ISBs have multi-line capabilities) and dial
their respective ISPs so that each ISB is connected to the
Internet. While each ISB connects to the Internet, the person using
the ISB hears progress tones, recorded music, or the like.
[0067] Once the ISBs are connected to the Internet, they connect to
the server, unless (as is rather unlikely) each party knows that
the other party has a static IP address and has that static IP
address on file. Each ISB sends its telephone number and IP address
to the server so that the server has a current IP address
corresponding to each telephone number. Each ISB communicates the
other party's telephone number to the server to retrieve the other
party's IP address. Once each party knows the other party's IP
address, the Internet telephone connection begins, and the ISBs
send voice packets to each other. The ISBs can also resolve each
other's IP address in other ways, such as through e-mail (POP3)
servers.
[0068] Of course, two users are not precluded from arranging to
call each other on the Internet at a certain time, in which case
they avoid PSTN charges altogether. However, the use of the ISBs
described above offers additional flexibility in that users can
choose to prearrange their Internet calls or initiate them over the
PSTN.
[0069] 3. Sending and receiving voice mail messages: The user
presses menu button 301 or otherwise issues a command to summon the
menu and follows the prompts to send and receive messages. The
digitized voices for such messages are sent as binary attachments
to e-mail messages; one ubiquitous standard for such binary
attachments is called MIME (multimedia Internet mail extensions).
Both parties should have e-mail access. If the calling party does
not already know the called party's e-mail address, the ISBSS or
another server can correlate telephone numbers with e-mail
addresses.
[0070] The ISB have the capability to dial in to check the e-mail
for voice messages periodically. If a voice message is waiting, the
ISB can so indicate by providing a flashing LED, by emitting a
special tone when the user picks up the telephone, or the like.
[0071] 4. Internet Audio Server (IAS) calls: These are calls made
through the ISB to access IASs, or Internet audio servers, which
are Internet servers (such as Web or FTP (file transfer protocol)
servers) configured to provide audio information. The user picks up
the telephone and presses the menu button 301 on the ISB. The menu
system uses voice prompts to prompt the user to access different
IASs. The ISB then accesses the selected IAS either by telephone or
by dialing the ISP and connecting to the IAS over the Internet. The
ISB can resolve the IP address of an IAS either by accessing the
server described above or by accessing a conventional domain-name
server (DNS), which is a server for correlating IP addresses and
domain names such that the DNS provides an IP address when given a
domain name. Once an IAS is known, the ISB can store the IP
address, since servers provided for access by the general public
normally have static IP addresses.
[0072] 5. ISB special server: As noted above, a server is provided
to allow the users of two ISBs to resolve each other's IP
addresses. Such a server is known as an ISB special server (ISBSS),
and it correlates telephone numbers to IP addresses. The ISBSS can
look up an IP address for an ISB which has previously accessed the
server and provided information correlating its telephone number
and IP address. The ISBSS does this by searching by the telephone
number, or the least significant digits of the telephone number,
provided by another party wishing to access that ISB. The ISBSS
also uses telephone numbers to find e-mail addresses and possibly
also the IP addresses of IASs. With the ISBSS, the ISBs do not have
to exchange information concerning their IP addresses directly
during the PSTN phase of a telephone call.
[0073] The ISBSS can also collect and report transactions,
statistical data about attempts, completions, etc. by type of call
request and customer, for engineering and marketing purposes. The
requirements for interfacing, processing and data storage with a
computer based server such as the ISBSS will be readily understood
by those skilled in the present state of the art. A fuller
description of the ISBSS will be set forth below.
[0074] 6. Compatibility with call waiting, caller ID, and other
enhanced telephone features: According to one embodiment of the
ISB, call waiting must be inactive to assure Internet call
connection continuity. A disable code can be programmed to
de-activate this feature when Internet telephone calls are in
process. It is presumed that users who are on a long distance call
do not want to be disturbed. Such disable codes are known in the
art; for example, it is known to configure communication software
to disable call waiting by dialing a code such as *70 and pausing
before every call. Another embodiment of the ISB not only allows
call waiting to function but also incorporate caller ID and other
premium telephone services. For example, an ISB can have integrated
caller ID and can even indicate whether the caller has an ISB,
e.g., by searching by the telephone number through the ISB's
database of completed calls.
[0075] These and other operations are implemented on hardware and
software which will now be described in detail. According to a
preferred embodiment, the ISB is implemented by realizing the
described modules by way of an existing personal computer or by
repackaging the necessary personal computer capabilities into a
commercially viable design. In the latter case, the ISB need not
include those hardware or software capabilities which are not
relevant to the functions which the ISB is expected to perform;
therefore, the hardware and software can be radically simplified
from those of a personal computer. In particular, the ISB can be
implemented in hardware and software compatible with MS-DOS, rather
than in the considerably more complicated and expensive hardware
and software associated with operating systems such as Windows 95
or Windows NT. In the alternative, a design based on a digital
signal processor (DSP) can be employed. Various elements of any
designed embodiment such as the modem and vocoder functions can be
implemented via hardware or software equivalents. Those skilled in
the art are familiar with the computer telephony modules and
software libraries which can easily implement the disclosed
modules. The following describes a commercially efficient approach,
and FIG. 2 shows a schematic illustration of this preferred
embodiment.
[0076] The ISB includes PC-compatible microcontroller
(microprocessor) 201, such as an Intel 80186 processor or an
equivalent. Microcontroller 201 includes integrated timers, direct
memory access (DMA) channels, serial links and interrupt handlers
and is supported by a memory system 202 including, for example,
ROM, SRAM, flash memory, or EEPROM. Microcontroller 201 and memory
system 202 together form the main processing unit for the ISB.
Memory system 202, besides providing working memory for the
operation of the ISB, also stores such code as is needed to operate
the ISB. For example, memory system 202 includes code for
establishing an Internet connection; such code is analogous to a
Winsock dialer on IBM-compatible PCs.
[0077] An internal DC-to-DC power converter 213 provides the proper
voltages to the various components within the ISB. An appropriate
external AC-to-DC adaptor interfaces the ISB to the available AC
power alternatives found in the U.S. and elsewhere.
[0078] The modem 202 may be implemented most advantageously via a
hardware modem or modem chip which is connected to the
microcontroller 201 and the Loop Start Line Controller 208 and data
access arrangement (DAA) 209, both of which are described below.
Modem 202 can be a Rockwell 14.4 modem or any other suitable modem,
although it should preferably be capable of a speed of at least
14.4 and should also preferably be upgradeable as new modem
standards emerge.
[0079] The vocoder 204 may be most advantageously implemented via
hardware which is connected to the microcontroller and which has
its own SRAM 214. The vocoder provides low bit rate voice
compression and decompression and interfaces the Telephone Set
Controller 205.
[0080] The Telephone Set Controller 205 includes a Subscriber Line
Interface Circuit (SLIC) and a CODEC 207 which is, advantageously,
connected to the vocoder. CODEC 207 allows SLIP or PPP connection
to the Internet.
[0081] Loop Start Line Controller 208 includes a Data Access
Arrangement (DAA) 209 and is connected to the modem 202 and the
telephone line 212.
[0082] A 2 FORM C relay 210 is provided, as illustrated in FIG. 2,
to connect the telephone 211 to either the telephone line 212 or
the Telephone Set Controller 205. When telephone 211 is connected
to telephone line 212, the ISB functions as a passive pass-through
device. When telephone 211 is connected to telephone set controller
205, communication between telephone 211 and telephone line 212
(i.e., between telephone 211 and the outside world) passes through
and is handled by the circuitry of the ISB, including telephone set
controller 205, vocoder 204, microprocessor 201, modem 202 and loop
start line controller 208.
[0083] Telephone 211 should preferably not be the sort of telephone
which has its own power source (e.g., cordless telephone or
integrated telephone and answering machine) or which manipulates
its signaling (e.g., speaker phone with echo suppression
technology).
[0084] Microprocessor 201 executes the software architecture shown
in FIG. 2A. Software architecture 2A01 is based on a
space-efficient embedded operating system such as ROM DOS 2A03,
which includes application component 2A05 and maintenance component
2A07. Maintenance component 2A07 interacts with the following
drivers. Telephone interface driver 2A09 allows the software to
interact with telephone set 211. G.723 audio CODEC driver 2A11
interacts with maintenance component 2A07, telephone interface
driver 2A09 and TCP/UDP driver 2A13. TCP/UDP driver 2A13, IP driver
2A15 and PPP driver 2A17 serve as modifiable, embedded networking
software for packetizing data and allowing communication with the
Internet; thus, they correspond to a Winsock driver on a
conventional PC running Windows 95, or NT. UART/modem driver 2A19
and telephone interface driver 2A21 allow communication with
telephone line 212. ("UART" stands for "Universal Asynchronous
Receiver and Transmitter" and refers to a chip used to interface a
modem with the rest of the hardware of a computing device.)
[0085] The software can be a combination of commercially available
software adapted for the ISB and proprietary software written
specifically for the ISB. However, the ISB can use commercial,
modified commercial or proprietary software or any combination.
[0086] As noted above, the hardware of the ISB can alternatively be
implemented with a DSP chip. Such an alternative implementation is
shown in FIG. 2B. As seen in this figure, ISB 2B01 includes
microprocessor 2B03, which can be like microprocessor 201 of the
embodiment of FIG. 2. Microprocessor 2B03 communicates via data and
address buses 2B05 with two 512 kB EEPROM's 2B07 and a 512 kB
RAM-2B09 which store the program code, data for the operation of
the ISB (which will be described in detail below) and the like and
provide working memory for the operation of the ISB. Microprocessor
2B03 also communicates via data and address buses 2B05 with modem
or modem chip 2B13, which can be the same as modem or modem chip
202 of the embodiment of FIG. 2, and with DSP chip 2B11. DSP chip
2B11 performs compression and decompression and thus performs
functions like those of vocoder 204 of FIG. 2. Modem 2B13 and DSP
chip 2B11 communicate via telephony interface 2B15 with telephone
set 1 and PSTN line 212. Microprocessor 2B03 also communicates with
serial flash memory 2B17, which stores device data, server data and
the like, and with front panel 2B19, which has LEDs (to be
described in detail below with reference to FIG. 3) for
communicating the status of the ISB to the user.
[0087] The ISB, whether constructed according to FIG. 2 or FIG. 2B,
is packaged in an enclosure measuring approximately 7 inches by 7.4
inches by 1.4 inches and having slots sufficient for ventilation. A
fan may also be provided if needed. The components shown in FIGS. 2
and 2B are mounted on a printed circuit board.
[0088] The hardware and software used in the ISB can be analogized
in the following manner to the hardware and software of a known PC
used for IT:
TABLE-US-00001 Function Known PC ISB Digitize voice Sound card
CODEC Compress data Compression algorithm Vocoder or DSP chip
executed on CPU Packetize data Winsock portable networking software
ISP access modem modem chip operating system Windows 95, 98 or NT
ROM DOS CPU Pentium .gtoreq.133 MHz Intel 80186 user interface
monitor and keyboard telephone keypad, earpiece
[0089] FIG. 3 shows a front or top view of an ISB. Front or top
panel 302 may include a logo 305. Status indicator LEDs 304, 306,
307 and 311 may be provided. Three of these LEDs may be used to
indicate whether the power is on or off the status of an Internet
call attempt and whether any messages are waiting. The fourth can
be used in various ways, such as to indicate whether the menu
feature is in use or whether an upgrade to the ISB software is
available (in which case the software can be upgraded in a manner
to be described below). Of course, other configurations of LEDs can
be used, as can other interfaces such as an alphanumeric LCD
display.
[0090] Buttons 301 and 303 may be used as already described. As an
alternative to the buttons, the ISB can be configured to listen to
the connection from telephone 211 to detect an off-hook state of
telephone 211 and to monitor the digits dialed. If the first digit
dialed after the telephone is picked up is a pound sign ("#"), the
ISB knows that the user wants to access the ISB's menu system. The
ISB generates a voice prompt to prompt the user to select one of
the following options by way of the keypad on telephone 211:
TABLE-US-00002 Digit Action 1 Reconnect or retry a call via the
Internet 2 Make a new call via the Internet 3 Listen to voice
messages 4 Send a voice message 5 Make an Internet test call (to
test both the operation of the ISB and the ISP access) 6 Program
the ISB 7 Upgrade the ISB 8 Make an off-net call 9, 0 Reserved for
future use
[0091] If the menu system is accessed in this manner, the menu
button is unnecessary. Also, because making an Internet call is a
menu option, the Internet button is also unnecessary. Thus, the
hardware and user interface of the ISB are simplified, and the ISB
has fewer mechanically actuable components to break. Once a user
becomes familiar with the menu system, he need not wait for the
voice prompt, but instead can simply pick up telephone 211 and dial
# and an appropriate digit to perform the function desired. Also,
to cancel any operation, the user can simply hang up.
[0092] To produce the voice prompts, the ISB can store sound clips
in an appropriate format in memory system 202 and play them to the
user through telephone 211. For example, one such sound clip can be
a recording of a voice saying, "To reconnect or retry your
telephone call on the Internet, press 1." Just as conventional
software can be supplied in different language versions, the ISB
can be supplied in different language versions with different
stored sound clips.
[0093] To cancel or start over, the user hangs up. If the ISB locks
up, it can be reset by unplugging and reconnecting the power
supply. Alternatively, the ISB can be equipped with a reset button
like those on known PCs.
[0094] FIG. 4 shows the back or bottom view of an ISB. Back or
bottom panel 402 can include telephone jack 404 for connection to
telephone 211, telephone jack 406 for connection to telephone line
212, optional port (serial, parallel, universal serial bus (USB),
etc.) 408 for connection to another device such as a PC, and power
jack 410. An AC-to-DC power adapter can be plugged in to power jack
410; the cumulative effect of the AC-to-DC power adapter and the
DC-to-DC power converter is to supply a +12-volt DC supply to the
circuitry of the ISB. Alternatively, the ISB can contain all of the
power conversion circuitry internally, in which case back or bottom
panel 402 can include a power cord to be plugged directly into a
wall outlet. Also, if the ISB is intended for use with a connection
other than to the analog PSTN, such as a connection to an ISDN line
or to a cable modem, jack 406 can be modified accordingly. Optional
port 408 can be used for any operation involving an exchange of
data between the ISB and some other device, such as programming and
testing the ISB at the factory and for attachment to some
peripheral such as a digital camera for videophone service or a
caller ID unit.
[0095] It will be readily apparent from FIG. 4 and the description
thereof set forth above that a user can easily install the ISB. The
user simply plugs telephone 211 into jack 404, a cord from
telephone line 211 into jack 406 and a power adapter into power
jack 410 to supply power from a wall outlet. Once the ISB receives
power, it undergoes a POST (power-on self test) routine, such as
that performed by a conventional PC. During the POST routine, all
LED's light up for a predetermined period of time, such as seven
seconds, to inform the user that the ISB is working correctly and
is in the POST routine. The ISB can also be configured to give an
error beep or an error indication through the LEDs if the POST
routine fails, as is also conventional in PCs. Once the POST
routine is completed, the ISB enters standby mode, in which it
monitors signals from telephone 211 to detect when the telephone is
picked up and which digits, if any, are dialed.
[0096] The ISB includes a housing that can be desk- or
wall-mounted. A premises wiring pattern and the number of
telephones sharing the same telephone line will dictate the ISB's
most advantageous installation.
[0097] Any or all components of the ISB which rely on code for
their operation can be made software-upgradeable. For example, the
modem can be software-upgradeable as modem technology advances and
as standards such as the recently announced 56K standard are
implemented, and the portions of the memory system containing code
for the operation of the microcontroller can be
software-upgradeable to allow for the H.323 Internet telephony
standard. When the user issues a command to upgrade the software
(e.g., by dialing # to access the menu and then by dialing 7), the
ISB connects via the user's ISP and the Internet to an upgrade
server to download and install the latest version of the ISB
software, an operation which typically takes four to six minutes.
The previous version of the software can be stored to allow the
upgrade to be undone locally with no need for access to the upgrade
server; to undo the upgrade, the user dials "*0#". For example, in
a 512 k EEPROM, 192 kB can be used for DOS and the BIOS (basic
input-output system, a set of routines which allow a microprocessor
to communicate with other hardware), 384 kB for the current version
of the application software, 192 kB for a scratch buffer, and 384
kB for the previous version of the application software. At the
factory, the ISB is provided with two copies of the same version of
the software; one of these copies is overwritten in the first
upgrade, while the other is available to undo the first upgrade.
Some upgrades may require assistance from the help desk (to be
described below), such as those allowing new extra-cost
features.
[0098] Each ISB stores information regarding that ISB. Such
information can include all information necessary for connecting to
the Internet (e.g., telephone number, user I.D. and password for
logging onto the ISP). The information can also include a record of
other ISBs with which the ISB has interfaced, including data for
each other ISB such as the telephone number and the static IP
address if any. The oldest and least used entries can be purged
periodically.
[0099] More specifically, the ISB stores device, server, billing,
and owner information and a friends directory. The device
information is typically programmed into the ISB at the factory and
includes the serial number, the manufacturing date, the hardware
version, the software version, and the feature key, which
identifies those features which the ISB implements. The server
information includes the IP addresses for the various servers which
the ISB needs to access, such as the primary and backup ISBSSs. The
owner information includes the telephone number, the ISP access
telephone number, any scripting required to log onto the ISP, logon
name and password, the domain names or IP addresses for the SMTP
and POP servers for e-mail, the e-mail address, and the e-mail
password. The SMTP server implements the simple mail transfer
protocol (SMTP) for sending e-mail, while the POP server implements
the post office protocol (POP) for receiving e-mail. Many ISPs use
the same server for both protocols. Other mail protocols exist and
can be used instead. The server and owner information can be
programmed locally by the user or over an Internet connection by an
agent at a help desk, which is described in detail below. The
friends directory is maintained automatically and in run-time and
has a data structure like that shown in the following table:
TABLE-US-00003 Record # Serial # Telephone # E-mail address Counter
1 100011 202-555-0102 hisname@someserver.com 25 2 100021
703-555-0103 hername@anotherserver.edu 11 *** *** *** *** *** 99
*** *** *** ***
[0100] The counter is increased by one for each conversation with a
particular person. When the number of entries to be stored in the
friends directory exceeds the number of allowable entries, the
entry with the lowest counter can be erased. Alternatively, the
time and date of the last conversation can be stored, and the entry
whose last conversation has the earliest time and date can be
erased.
[0101] The steps carried out by both parties in placing an IT call
using two ISBs are shown in the flow chart of FIG. 5. The calling
party calls the called party via the PSTN in step 502, and the
called party answers in step 504. In step 506, the parties agree to
switch to an IT call, and in steps 508 and 510, each party's ISB
disconnects (hangs up on the PSTN connection) and connects to that
party's ISP. In steps 512 and 514, each party's ISB sends the
calling and called telephone numbers and that ISB's IP address to
the ISBSS. In step 516, each party gets the other party's IP
address from the ISBSS, and in step 518, the parties talk via IT.
The call is ended in step 520, and the parties hang up in steps 522
and 524.
[0102] During the call shown in FIG. 5, each party's ISB operates
as shown in FIG. 6. In step 602, the ISB acts as a passive conduit
for passing the call from the telephone to the PSTN. In step 604,
the user presses the button to switch to an IT call. In step 606,
the ISB hangs up on the PSTN call, and in step 608, the ISB calls
the user's ISP and logs on. In step 610, the ISB contacts the ISBSS
and sends the calling and called telephone numbers and that ISB's
IP address. In step 612, the ISBSS sends the ISB the IP address of
the other party's ISB, and the ISBs open an IT connection in step
614. In step 616, the user hangs up the telephone, and in step 618,
the ISB logs off the ISP and hangs up from the telephone connection
to the ISP.
[0103] A technique called "double packets" can be implemented to
improve voice quality. In this technique, every packet is sent
twice. Thus, if packets are dropped or sent out of sequence, voice
quality will most likely not suffer. Packet dropping and
out-of-sequence packet transmission are usually not a problem when
the users' ISPs communicate over a common backbone or over
backbones which have a peering arrangement (i.e., freely transmit
packets over each other's facilities). However, if the two ISPs
communicate over an NAP (network access point), packet dropping and
transmission out of sequence are problems, which double packet
transmission corrects.
[0104] There is a special kind of call known as a self-test call.
When the user dials #5, the ISB initiates a call to a call
completions server via the user's ISP. If the call is completed
correctly, the user hears a recording from the call completions
server to that effect. Otherwise, the user knows that there may be
a problem with the ISB.
[0105] To implement the functionality noted above, the ISB can
perform any of several calling operations: passive operation,
establishing a connection to the ISP, PTIC (PSTN-to-Internet
calling), MMIC (meet-me Internet calling), checking messages,
sending messages, etc. These calling operations will now be
explained with reference to FIGS. 7A-7E and 8.
[0106] Passive operation will be explained with reference to FIG.
7A, which shows ISB 100 connected between telephone 211 and
telephone line 212. In this operation, the ISB monitors the
off-hook status of the telephone and the dialed digits via the
connection to the telephone. Via the connection to the telephone
line, the ISB monitors ring signals (incoming calls). If the first
dialed digit is the pound sign ("#"), the ISB allows the user to
control it via the menu system. Because IT is invoked through the
menu system (and more specifically by dialing "#1"), IT is not
invoked unless the first dialed digit is a pound sign. If more than
six digits are called, the ISB operates as a PTIC caller, to be
explained below, while if a ring signal is received from the
telephone line, the ISB operates as a PTIC called party, to be
explained below. Once the telephone is placed on-hook, all
operations of the ISB are reset except the mode and the digit
buffer.
[0107] Connection to the ISP will now be explained with reference
to FIG. 7B. The modem is initialized, and telephone line 212 is
monitored for a dial tone. ISB 100 dials the ISP access number to
connect via PSTN 702 to modem rack 704 of the ISP. The modem of the
ISB and a modem reached in modem rack 704 negotiate the baud rate
and the protocol, whereupon ISB 100 is connected to the facilities
of ISP 706. The ISB and the ISP perform any authentication
procedure required, and the ISB selects "PPP" from the ISP's logon
menu, if any. The ISB and the ISP then start communication by PPP,
and PAP (the password authentication protocol) is carried out if no
authentication has been performed before. The ISB is then connected
by TCP to the ISP and thus via line 708, such as a T1 or T3 line or
the like, to Internet backbone 710. If the call to the ISP results
in a busy signal, the user can simply wait and call again.
Alternatively, the ISB can be configured to store and dial multiple
access numbers for one or more ISPs.
[0108] In case a user's ISP requires a special logon procedure, the
ISB can have a scripting facility. This facility allows the ISB to
store a logon script and to play the script to satisfy the ISP's
logon requirements. The scripting language can be the same as that
used for dial-up networking in Microsoft Windows 95, which is known
in the art and will therefore not be explained here.
[0109] The script can be supplied to the ISB in different ways. For
example, the user can compose the script on a PC and transfer the
script to the ISB over a serial connection, or the agent at the
help desk (to be explained in detail below) can remotely program
the script into the ISB. Alternatively, the ISB can store a
boilerplate script with various components which can be enabled or
disabled remotely by the agent. Still another way of programming
the script into the ISB is to log on manually, while the ISB is
connected to a PC over a serial connection, and to issue a command
to automate the logon, as certain terminal emulation programs do.
In any event, it should be possible to allocate 1,024 bytes in
memory to store any script.
[0110] The operation of making a PTIC call will now be explained
with reference to the diagram of FIG. 7C and the flow chart of FIG.
8. In FIG. 8, operational steps or states occurring at the same
time are indicated by the same reference numeral, except suffixed
by A (caller A's state), B (caller B's state) or C (user actions or
common states).
[0111] Caller A uses telephone 211A, ISB 100A and ISP 706A, while
caller B uses telephone 211B, ISB 100B and ISP 706B. Once the PTIC
call is completed, they communicate over Internet 712, generally
after communication over the Internet with ISBSS 714.
[0112] At the time at which user A dials user B in step 802C, user
A's ISB is passive and off hook (step 802A), while user B's ISB is
passive (step 802B). As user A dials, his ISB records the digits
dialed in the digit buffer in step 804A and enters "PTIC caller"
mode in step 806A. Then, in step 808A, user A's ISB becomes
"passive," i.e., acts as a passive pass-through between user A's
telephone set and the PSTN. In step 808C, user B's telephone rings,
and in step 808B, user B's ISB goes into the "PTIC called" mode.
User A talks to user B in step 810C, and once they agree to an IT
call, they both hang up in step 812C. During these operations,
their ISBs are "passive" (steps 810A, 810B, 812A, 812B). They both
pick up their telephones and dial # in step 814C, whereupon their
ISBs go into menu mode in steps 814A and 814B. They both dial 1 in
step 816C to initiate ISP connections in steps 816A and 816B. While
they both monitor (listen for the ring-back tone) in step 818C,
their ISBs remain connected to their ISPs in steps 818A and 818B.
The ISBs connect to the ISBSS in steps 820A and 820B, and the users
hear ring-back tones in step 820C. The ISB data are exchanged in
steps 822A and 822B, and the users hear a confirmation tone in step
822C. While the users continue their conversation in step 824C, the
ISBs undergo dynamic adjustment in steps 824A and 824B. If either
user's ISP drops that user's connection, that user can simply dial
#1 again to be reconnected to the ISP and thus to the other
user.
[0113] Dynamic adjustment will now be described with reference to
FIG. 8A. Dynamic adjustment starts in step 8A02. In step 8A04, the
first hundred packets (about one-third of a second) are monitored
to determine transmission quality. More specifically, the baud rate
and the percentage of dropped packets are measured. In response to
these measurements, it is determined in step 8A06 whether one or
more of the following need to be adjusted to maximize transmission
within the bandwidth provided by the baud rate: the degree of
compression (e.g., 6.3, 5.3, 4.8 or 4.1 kB/sec), the packetization
(number of frames per packet, from one through five, which is also
a measure of delay) and whether double packet transmission is
turned on or off. For example, if the baud rate is 14.4 kilobaud
and the percentage of dropped packets is below 10%, the ISBs may be
adjusted to 6.3 kB/sec, two frames per packet and no double
packets. At the same baud rate and a percentage of dropped packets
of 10% or more, the ISBs may be adjusted to 4.1 kB/sec, five frames
per packet and double packets. If the connection rate is greater
than 16 kB and the rate of lost packets is 10% or less, the ISBs
are adjusted to 6.3 kB/sec compression, one frame and no double
packets; at the same connection rate and a higher rate of lost
packets, the number of frames is increased, and double packets are
used. The ISBs may implement this dynamic adjustment through a
look-up table in the software; i.e., every combination of the baud
rate and the percentage of dropped packets will correspond to a
previously calculated and stored set of settings. For example, the
look-up table is consulted in step 8A08, and the adjustment is made
in step 8A10. Alternatively, calculation of the settings may be
done on the fly. Once the adjustment is made, or if no adjustment
is required, the dynamic adjustment ends in step 8A12. The ISB can
be configured to abort the connection or any operation if the baud
rate is less than 14.4 kB.
[0114] The hardware shown in FIG. 2 or 2B can be used to implement
the dynamic adjustment of FIG. 8A. For example, the modem can
detect the baud rate in a known manner, while the look-up table can
be stored in whatever memory is provided (RAM, EEPROM, etc.), and
the microprocessor can perform the remaining operations.
[0115] The ISB can be configured to give the following error
messages, which can be used by either a user or a technical support
person to determine why a call has not been completed normally:
TABLE-US-00004 Error code Problem 0 No dial tone 1 ISP busy 2 ISP
did not answer 3 Logon failed, no logon prompt 4 Logon failed, no
password prompt 5 Insufficient baud rate 6 PPP authentication
failed 7 PPP failed 8 PPP timed out 9 Server did not connect 10
Server did not respond 11 Server rejected transaction 12 Reception
terminated 13 Transmission terminated 14 Number not programmed
Error codes 20-24 refer to sending a voice mail message, to be
described below. 20 DNS did not answer 21 SMTP address wrong 22
SMTP user ID wrong 23 SMTP rejected message 24 SMTP disconnected
Error codes 33-34 refer to receiving a voice mail message, to be
described below. 30 DNS does not answer 31 POP address wrong 32 POP
user ID/password wrong 33 POP stopped sending 34 POP disconnected
Error codes 40-42 refer to user programming of the ISB through the
telephone keypad. 40 Character not defined. 41 Character entered is
not permissible where entered. 42 Too many characters.
[0116] The error codes can be given to the user in the form of
voice prompts. For example, if there is no dial tone, the ISB can
play a first sound clip of a voice saying, "I'm sorry, but there is
a problem with your Internet access; please try again. Error code .
. . " and a second sound clip of a voice saying, "zero." The user
can consult the manual to find the significance of error code 0. In
the case of errors which require a call to technical support, the
user can make a note of the error code.
[0117] Variations on the PTIC call avoid incurring PSTN charges at
all. Such variations include a previously agreed-upon signal that a
particular person is calling, such as letting the telephone ring
twice and then hanging up, and letting the telephone ring just long
enough for caller ID information to be sent and then hanging up.
The users then call each other back over the Internet as for a
meet-me Internet call, which will now be described.
[0118] The MMIC, or meet-me Internet call, is a simplified version
of the PTIC. In the MMIC, the users have previously agreed to call
each other at a certain time, so no PSTN handshaking is
required.
[0119] In the MMIC, both users dial #2 to access MMIC operation in
their ISBs via the menu. User A enters user B's number, which user
A's ISB verifies in its directory, and user A's ISB enters
MMIC-caller mode. User B enters user A's number, which user B's ISB
verifies in its directory, and user B's ISB enters
MMIC-called-party mode. The rest of the conversation proceeds as
for a PTIC call, i.e., steps 814A-C to 824A-C in FIG. 8.
[0120] Once two users have already called each other using the ISBs
or otherwise added each other to their friends databases, MMIC can
be used with a speed-dialing technique in which a user dials the
last six digits of the other user's telephone number followed by #,
regardless of where in the world the other user is, thereby
avoiding long and confusing digit sequences for conventional
international dialing. The ISB then matches the dialed last six
digits with the friends data stored in the ISB to identify the
other ISB which is to be called.
[0121] The last six digits can be used for a unique identification
of up to a million other ISBs. While it is possible that a user's
friends database will contain two entries having the same last six
digits, this possibility is remote. Even if such a situation does
arise, the ISB can be configured to prompt the user to dial more
digits to identify the called party uniquely.
[0122] Checking and sending messages will now be explained with
reference to FIGS. 7D and 7E. To check messages, the user dials #3
to enter message checking through the menu. The ISB connects to the
ISP and then connects through ISP 706 and Internet 712 to POP
server 716. Once this last connection is achieved, the ISB
downloads and plays the first message. The user can then dial 1 to
repeat, 2 to go to the next message or 3 to erase a message, much
as he would with an answering machine. To send a message, the user
dials #4, whereupon the ISB connects to the ISP and then connects
through ISP 706 and Internet 712 to SMTP server 718 (the function
of the SMTP server having been described above). The user can then
record a message and then send it via the SMTP server to the
recipient's e-mail address. The ISB can be configured to impose a
time limit on outgoing messages (e.g., 60 seconds). The ISB can
also be configured to poll the ISP periodically (e.g., four times a
day or some other interval which is either set in the factory or
programmed by the user) to check for message and to give an
indication to the user via an LED or the like when messages are
waiting.
[0123] The ISB can also be configured to poll the ISP periodically
(e.g., four times a day or some other interval which is either set
in the factory or programmed by the user), whenever a call is
completed over IP, or both to check for message and to give an
indication to the user via an LED or the like when messages are
waiting. In one configuration, polling takes place only when all
three of the following conditions are satisfied: (1) the polling
period set in the ISB has expired, (2) the telephone has not been
in use in the last two minutes and (3) no ring signal has been
received in the last two minutes. Of course, the ISB can be
equipped with an internal clock, such as those used in conventional
IBM-compatible PCs, to allow periodic polling.
[0124] Each voice mail message is stored on the recipient's POP
server in the form of an e-mail message with the sender's e-mail
address listed in the "From:" field, a standard subject such as
"ISB voice mail message" and a MIME attachment of the voice mail
message in an appropriate sound file format. If the recipient
checks his e-mail on the POP server with a conventional e-mail
program such as Eudora, he will see such message interspersed among
conventional e-mail messages. The ISB can distinguish the voice
mail messages from the conventional e-mail messages by the
subject.
[0125] The ISBSS will now be described in detail. The functionality
described for the ISBSS can be implemented on a Sun Microsystems
workstation running Solaris 2.6 or on any other sufficiently
powerful computing device running an appropriate operating system.
The server program executed by the ISBSS can be written in C++ or
in any other suitable language. The primary purpose of the ISBSS,
but not the exclusive function, is to provide connection
information for two ISBs to engage in an IT call, since it is
contemplated that the ISBs will not exchange information during the
PSTN portion of the call. In addition, the ISBSS documents each
completed call and each request for any other service, such as
voice messaging and software upgrade requests, requested from ISBs
and supported by the vendor of the ISBs.
[0126] The ISBSS is an iterative server. The server functions can
be implemented in a single process and do not require threads. Each
IT call involves two connections to the ISBSS, one from each of the
ISBs. Each connection is kept open at most 200 msec after the
three-way handshake is complete. The ISBSS software makes no
blocking calls to any kernel function unless the ISBSS software is
completely idle. In any connection to the ISBSS, there is one
datagram sent in each direction.
[0127] The ISBSS provides service to the users of the ISBs by
facilitating an exchange of IP addresses between two ISBs whose
users want to communicate with each other. It does so by accepting
a TCP connection request from each client, matching corresponding
connection requests and sending the IP address of one of the ISBs
to the other ISB. Otherwise, the ISBs might have to communicate
their IP addresses to each other during the PSTN phase of the call.
Such a procedure would require the modems of the ISBs to be set
twice, once for the PSTN phase of the call and once for the IT
phase of the call, and would render the MMIC call impossible. The
use of the ISBSS allows the ISBs to set their modems only once, for
the IT phase of the call, and makes the MMIC call possible.
[0128] The operation of the ISBSS will be described with reference
to the flow chart of FIG. 9A. In steps 9A02 and 9A04, each ISB
sends the ISBSS a connection request, which is a data string
including the following: that party's serial number, the other
party's serial number, that party's telephone number, the other
party's telephone number, that party's IP address, version number
and the like. For a PTIC, the calling party's telephone number is
not required. The ISBSS searches for a match between the ISB and a
waiting list of ISB's. If there is no match, as in step 9A06 (where
caller A's request has been received fast), the ISB is appended to
the waiting list or queue in step 9A08 and is instructed by the
ISBSS to expect a call from another ISB. If there is a match, as in
step 9A10 (where caller B's request has been received second), the
ISB matches the requests in step 9A12 to find the IP address of the
other party's ISB in step 9A14. In step 9A16, the ISBSS forwards
caller A's IP address to caller B's ISB, and in step 9A18, caller
B's ISB attempts to contact caller A's ISB using the thus obtained
IP address, whereupon the ISBSS has no more involvement in the
call. Thus, when two parties want to call each other, the first
received connection request is queued, and the second received
connection request is answered with the IP address of the first
received request.
[0129] By holding connection requests in a data structure in this
manner, the ISBSS can avoid holding open a TCP connection to any
particular ISB for more than a few microseconds, thus reducing load
on the ISBSS. In fact, the ISBSS can break the TCP connection
immediately upon receiving the connection request.
[0130] The ISBSS can also send commands to an ISB while processing
a connection request. Such instructions can, for example, instruct
the ISB to modify the friends data or other data stored locally in
the ISB.
[0131] As the number of ISBs in use increases, more ISBSSs can be
added. Multiple ISBSSs can coordinate their services; for example,
an ISBSS can send an instruction to an ISB if the connection
request should be made to another ISBSS.
[0132] The ISBSS stores telephone numbers in BCD (binary coded
decimal) notation with the least significant digit of the telephone
number stored in the most significant nibble (four bits) of the
first byte (8 bits) of the telephone number string. With this
approach, the ISBSS can allow the possibility of six-digit dialing
to any ISB in the world. The code to implement this feature is
shown in FIGS. 10A and 10B.
[0133] A state diagram of the ISBSS is shown in FIG. 11. The basic
design of the ISBSS software is that of a finite state machine. The
states in the machine are prioritized such that if conditions allow
the ISBSS to enter more than one state simultaneously, the higher
priority state is entered first. After completing work to be done
in any given state, the machine always returns to the "idle" state.
The states are listed below, with a priority number of each state;
a higher number indicates a higher priority.
[0134] Idle (0): The default state, in which the ISBSS does
housekeeping on its internal data structures while waiting for
requests for service which would send it into some other state.
[0135] ISB Connection Request (4): The ISBSS enters this state
after completion of a three-way handshake. The ISBSS accepts all
pending connection requests at this time.
[0136] ISB Connection Read (5): The ISBSS enters this state when a
particular connection has data ready to be read by the ISBSS. The
data are read, verified and processed. The need to write the given
connection is announced.
[0137] ISB Connection Write (6): The ISBSS enters this state only
when a particular connection is ready to write the single datagram
which the ISBSS writes to each connection. The write takes place,
and the disconnect timer is set to expire in a predetermined time,
such as 200 msec.
[0138] ISB Connection Disconnect (7): The ISBSS enters this state
only when the disconnect timer expires for a particular connection.
The ISBSS aborts the connection and frees up any space used to
maintain the connection.
[0139] Telnet Connection Request (1): In addition to serving ISB
requests, the ISBSS has a Telnet-like interface for issuing
commands to the ISBSS. The ISBSS enters this state only when the
listening service indicates that a request for connection has been
completed. Only one such Telnet connection is permissible at a
time. Each new request results in a dropping of the previous
request. The commands include --A to set a parameter (such as the
connection list time out in seconds and the billing file size in
records, with the syntax being --A parametername newvalue), --B to
dump the billing file, --C list to list the commands currently
available, --C set (actual command) to send that command to all
connection requests, --H for help, --L for a parameter list, --M n
to monitor for n minutes if n>0 or to turn off monitoring if
n=0, --Q (password) to quit, --T on or --T off to turn testing on
or off, and --V (serial number) (status) to add the given serial
number to the list of invalid serial number if (status)>0 or to
remove the given serial number from the list of invalid serial
numbers if (status)=0.
[0140] Telnet Connection Read (2): The ISBSS enters this state only
if a command has been received on the Telnet connection and is
ready to be read.
[0141] Telnet Connection Write (3): Everything which needs to be
sent to the Telnet connection is buffered asynchronously in a
message list. The ISBSS enters this state and sends a single
message if the message list is not empty.
[0142] In a connection with an ISB, the ISBSS receives a connection
data structure and sends a response data structure. The connection
data structure is shown in FIG. 11A, wherein the tx_data array has
a structure shown in FIG. 11B and the tx_BillingData structure is
shown in FIG. 11C. The response data structure is sent to every
connecting ISB unless the incoming datagram is incorrect and has a
structure shown in FIG. 11D, wherein the tx_data array has a
structure shown in FIG. 11E.
[0143] The ISBSS is able to monitor its own behavior over a
specified range of any number of minutes. The number of minutes is
specified by a Telnet command described above. The output of the
monitoring process is shown in an illustrative example in FIG. 11F.
The data shown in FIG. 11F show the number of connection requests
and the manner in which they were processed.
[0144] The ISBSS is also able to maintain a log of any errors or
suspect situations which arise in running the server program. A
sample log file is shown in FIG. 11G.
[0145] While it is contemplated that the ISBSS will be a public
server accessible to all ISB users, it is also possible that an
ISBSS will be supplied, either as a workstation with the software
installed or as software for installation on a separately supplied
workstation, to an organization which wishes to maintain its own
dedicated ISBSS to supply connection information to ISBs within
that organization. The ISBs can be programmed to use this dedicated
ISBSS for calls within the organization or a public ISBSS for other
calls, which are called off-net calls and initiated by dialing #8.
Off-net calls can also be made by users of the public ISBSS to call
one another via a backup ISBSS when their usual ISBSS is down and
automatic reroute routines fail.
[0146] MMIC calls are treated similarly to PTIC calls. In MMIC
calls, it does not matter which ISB is the calling ISB and which is
the called ISB, so that the ISBSS can assign these roles
arbitrarily. In an MMIC call, the users may not coordinate the time
of their call properly, in which case the calling party's request
remains in the queue in the ISBSS. Either the ISB or the ISBSS can
be configured to wait a certain period of time and request via a
voice prompt that the user try the call again later.
[0147] In sending voice mail, the ISBSS has no involvement beyond
sending a "Go ahead and send your voice mail" message, whereupon
the ISBSS disconnects. In the Interne test call, the ISBSS
disconnects after sending a "test complete" message.
[0148] The ISBSS can be used to program the ISB automatically as
needed. The ISBSS uses the same commands which would be used to
program the ISB from a PC over a serial connection. The ISBSS
programs server information, e.g., the ISBSS's IP address and the
feature key.
[0149] Another use of the ISBSS is to notify a customer that an
upgrade is available. Whenever the ISB contacts the ISBSS, the
ISBSS can supply the current software version number, which is
compared with the version number of the software in the ISB. If the
current version number is higher, an LED lights up on the ISB to
inform the customer of the availability of the upgrade. The ISBSS
supplies the ISB with the IP address of the upgrade server from
which the upgrade is available and then disconnects.
[0150] In the programming and upgrade notification operations just
described, the ISBSS can send the following commands to the
ISB:
[0151] "Turn on the `upgrade available` LED."
[0152] "Use the accompanying IP address as the new address for the
main ISBSS."
[0153] "Use the accompanying IP address as the new address for the
backup ISBSS."
[0154] The ISBSS can also reject a connection request, for example,
if a caller's bill is sufficiently overdue, if the serial number or
telephone number in the connection request is invalid, or if the
ISBSS lacks memory or process time. When an ISB's attempt to
contact the ISBSS fails three times, the ISB assumes that the ISBSS
is not functional and tries to connect to a secondary ISBSS.
[0155] Each connection to the ISBSS is accompanied by data
describing the service most recently completed by the connecting
ISB (usually about the most recently connected telephone call
before the current call request). Such data are written to a log
file for future processing.
[0156] Other servers besides the ISBSS can be used. For example, a
backup ISBSS can be added and can become active when the main ISBSS
fails or passes control. Also, auxiliary servers such as an upgrade
server, an inquiry server, an H.323 server, a commercial server and
the like can be used.
[0157] A particular server which can be used with the ISB system is
called a billing serer. The billing server maintains information
regarding each completed IT call for billing purposes. The ISBSS
can supply this information to the billing server. The billing
record for each call includes the caller telephone number, the
caller serial number, the called telephone number, the called
serial number, the start time and date, the call duration and the
quality of the connection. To determine the quality of the
connection, the billing server or another server can maintain a
statistical record, either globally or for each call. The
statistical record can include such information as the percentage
of lost packets, the percentage of late packets, the percentage of
packets out of sequence, the percentage of discarded transmission
packets, the percentage of discarded reception packets, and, for
each of the parties to the call, the baud rate, the compression
rate, and the frames.
[0158] The billing information is collected for all different
transactions of an ISB. To make this process more efficient, the
billing information about a transaction is passed to the billing
sever at the beginning of the next transaction.
[0159] The ISB generates a billing record as follows. When the ISB
contacts the ISBSS for a transaction, the ISB receives the current
time from the ISBSS and produces a partial billing record which
includes the start time and the telephone number of the other party
(the latter field being left blank when it is inapplicable, e.g.,
when checking messages). At the end of the transaction, the ISB
adds the duration to the partial billing record to produce a
complete billing record, which is provided to the billing server at
the beginning of the next transaction.
[0160] A feature which a company selling ISBs can provide to
enhance the functionality of the ISBs is called the "help desk."
Through the help desk, customer service agents can assist customers
by remotely programming their ISBs, answering questions about the
service, upgrade the software in the ISBs, etc.
[0161] FIG. 9 shows a connection between a customer's location 900C
and an agent's position 900HD at the help desk. The help desk has
one or more call center positions 900HD, each equipped with a
standard telephone 211 HD, a computer or data terminal 908 and a
specially equipped ISB 100HD connected to computer or data terminal
908 via a serial port or other connection such as serial port 408
of FIG. 4. The customer connects to the help desk via PSTN 902,
customer's ISP 904C, Internet 906 and help desk's ISP 904HD. The
agent can use ISB 100HD to access, program, upgrade and test
customer's ISB 100C. The agent can change the data stored in ISB
100C (for example, the device data, server data and owner data).
The help desk does not have to change the data maintained
automatically by ISB 100C or by other servers (e.g., friends data,
billing data and service records). Also, the agent and the customer
can talk via telephones 211C and 211HD, either in voice over data
via the Internet or in voice-only mode via the Internet or the
PSTN, so that the agent can answer the customer's questions. The
user can initiate a voice-over-data conversation by dialing
*0#.
[0162] Programming of the ISB from the help desk takes place in the
following manner. The customer and the agent engage in a
conversation, either by IT or by the PSTN. If the agent decides
that the customer's ISB 100C is to be remotely programmed from the
help desk, the agent instructs the customer to dial *0# into
telephone 211C. The agent verifies that the customer's ISB 100C has
accepted this code to go into voice-over-data mode and enters a
similar command to set his own ISB 100HD to voice-over-data mode.
The ISBs 100C and 100HD perform a modem handshaking and then start
a PPP link between them. Once the link is established, the
bandwidth is shared between voice and data, and the agent and the
customer can resume their conversation while the agent accesses,
examines and programs the customer's ISB 100C.
[0163] The agent's computer or data terminal 908 has software to
allow the agent to access, examine and program the customer's ISB
100C in this manner. The software displays a window into which the
agent enters his own identifying information, device data such as
the serial number, feature key and hardware and software versions,
server IP addresses, and the user data. The window also has buttons
to allow the agent to read the data stored in the customer's ISB,
write data to the customer's ISB, activate voice-over-data mode,
save information about the customer's ISB to disk for future
reference, and load that information from disk. The window offers
menu options to allow the agent to log on and off his position at
the help desk, to change the serial port settings for his position
at the help desk, to select the source for data being accessed as
local (the help desk position) or remote (the customer's ISB) and
the like.
[0164] As those skilled in the art will readily appreciate, the
various components described above form a coherent system which is
shown in FIG. 12. In this system, multiple customer locations 900C
and help desk location 900HD, which have already been described,
interface via PSTN 902 and ISPs 904C, 904HD with one another and
with ISPs 904S, which allow access to one or more ISBSSs 1201, one
or more e-mail (POP, SMTP, IMAP (which is another mail protocol),
etc.) servers 1204, one or more billing servers 1206, one or more
Web servers 1208 and any other servers or other system components
which can be used.
[0165] The present invention can be adapted for use with the H.323
communication standard, which will now be described briefly with
reference to FIG. 13. The H.323 standard provides interoperability
among products from multiple vendors. The standard includes the
H.320 standard for ISDN (integrated services digital network)
communication and H.324 for the PSTN. The standard provides for
encapsulation of UDP packets (which have been identified above) as
RTP (real-time transport protocol) packets.
[0166] FIG. 13 shows various components of an H.323 system. Those
skilled in the art will readily appreciate that not all components
shown in FIG. 13 will necessarily be present.
[0167] H.323 system 1300 is implemented on LAN (local-area network)
1302. Terminals 1304 are used by users to communicate; each
terminal 1304 can include an ISB, with or without video
capabilities, or an PC with audio or audio-video capabilities.
Gateway 1306 provides interoperability with other networks, e.g.,
over PSTN 1308 or ISDN line 1310. MCU (multipoint control unit)
1312 control conferencing among three or more terminals. Gatekeeper
1314 performs network functions such as bandwidth control and
translation between IP addresses and names by which terminals 1304,
gateway 1306, etc. are known to LAN 1302.
[0168] The ISB software is written such that at any time during the
operation the user can terminate whichever operation is in progress
by simply hanging up the telephone and can hear a dial tone by
picking up the telephone again. There might be instances in which
the hang-up is not recognized by the software because of unexpected
interactions between the software and real-life conditions. To
prevent the ISB from locking up and possibly blocking the telephone
from the user, a watchdog timer can be implemented to recover from
these situations and reset the system. In all other instances in
which the ISB recognizes that an error has occurred, it plays a
prompt which in general terms explains the condition followed by an
error code which helps the user to troubleshoot the problem by
referring to the manual or which helps the agent at the help desk
to diagnose the problem. The error codes have been listed above,
although, of course, other error codes could be assigned as
needed.
[0169] In the instances in which the ISB expects the user to enter
data or hang up, a timer can be set with a predefined time-out
value. If the user does not respond within time-out period, the
prompt is repeated. This process can be repeated up to three times,
and if there is no response from the user, then the ISB goes
on-hook and, after a short delay, back off-hook.
[0170] The ISB can be tested at the factory or elsewhere in the
following manner. The ISB is connected to a telephone and to a
computer in the manner described above. The computer has
appropriate testing software installed thereon. The tester makes a
call through the ISB to a second ISB which has been tested and is
known to work properly. Any aspect of operation of the ISB under
test can be tested, and a report can be generated.
[0171] The foregoing detailed description covers interfacing a
wireline analog version of the ISB and is illustrative of the
various preferred embodiments of the present invention which also
include wireline digital versions which are ISDN or LAN based as
well as wireless analog or digital versions, either cellular or PCS
(personal communication systems). The ISB can also be adapted to
work with facsimile machines. The invention is not limited to
embodiments using a SLIP, PPP or other dialup connection to the
Internet; instead, any connection to the Internet or another
secondary network, such as a T1 line or a cable modem, can be used.
Also, while it is contemplated that a caller will usually want to
speak to one called party at a time, conference calls can be
implemented with no difficulty. In addition, ISBs can be made with
inexpensive digital cameras and LCD screens to allow videophone
service by using Internet audiovisual conferencing software such as
CU-Seeme. ISBs can also be provided with encryption. Moreover,
modifications disclosed separately can be combined in any
technically feasible manner, while modifications disclosed together
can be implemented separately wherever technically feasible. It
will be appreciated that numerous variations and changes can be
made not only to provide a range of services but also to interface
the many different devices used to access the PSTN, including
personal computers and laptops, without departing from the scope of
the invention as defined in the accompanying claims.
* * * * *