U.S. patent application number 08/868649 was filed with the patent office on 2001-11-01 for telephone doubler arrangement.
Invention is credited to HANSSON, ALLAN, TONNBY, INGMAR.
Application Number | 20010036171 08/868649 |
Document ID | / |
Family ID | 20402881 |
Filed Date | 2001-11-01 |
United States Patent
Application |
20010036171 |
Kind Code |
A1 |
TONNBY, INGMAR ; et
al. |
November 1, 2001 |
TELEPHONE DOUBLER ARRANGEMENT
Abstract
A method and a device for providing a telephone service to a
subscriber (A) which over a computer (2) and a modem (4) has an
ongoing Internet session with a an Internet access server (8) over
an IP link established over a connection in the telephony network.
A telephony application (11) allowing for voice transmission over
said IP connection is running on the computer. In accordance with
the invention a telephony server (10) is provided. The telephony
server has access to the public network and to the Internet access
server (8). Upon start up of the telephony application the
telephony server requests forwarding of calls to the subscriber's
own telephone number to go to the telephony server from which they
are transported to over the IP access server to the subscriber's
computer. Speech is transported as compressed audio in a manner
known per se.
Inventors: |
TONNBY, INGMAR; (STOCKHOLM,
SE) ; HANSSON, ALLAN; (STOCKHOLM, SE) |
Correspondence
Address: |
BURNS DOANE SWECKER & MATHIS L L P
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Family ID: |
20402881 |
Appl. No.: |
08/868649 |
Filed: |
June 4, 1997 |
Current U.S.
Class: |
370/352 ;
370/401 |
Current CPC
Class: |
H04M 3/54 20130101; H04M
2242/22 20130101; H04M 11/06 20130101; H04M 2203/156 20130101; H04Q
2213/13298 20130101; H04L 12/2856 20130101; H04L 12/5692 20130101;
H04L 12/2898 20130101; H04Q 2213/13106 20130101; H04M 3/382
20130101; H04M 3/42289 20130101; H04M 3/436 20130101; H04M 3/4285
20130101; H04M 7/129 20130101; H04Q 2213/13389 20130101; H04M 3/428
20130101; H04Q 2213/13209 20130101; H04Q 2213/13199 20130101; H04Q
11/0457 20130101; H04M 3/42102 20130101; H04M 7/0057 20130101; H04Q
2213/13093 20130101; H04Q 2213/13204 20130101; H04M 7/122 20130101;
H04M 7/0033 20130101; H04Q 3/72 20130101 |
Class at
Publication: |
370/352 ;
370/401 |
International
Class: |
H04L 012/66; H04L
012/50; H04L 012/28 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 4, 1996 |
SE |
9602212-4 |
Claims
1. A method of providing a telephone service to a subscriber which
has an ongoing session with an Internet access server over an IP
link (14) established in a public or private network, said IP link
extending between a data communication device (4) at the current
location of the subscriber and an Internet access server (8) at the
site of an Internet gateway node, said data communication device
being connected to a data terminal equipment (2) at said current
location of the subscriber, said data terminal equipment having a
telephony application allowing for voice transmission over the IP
link characterized by providing a telephony server (10) that has
access to the public network and to the Internet access server,
redirecting a call, using as destination the telephony number of
said subscriber, to said telephony server, and connecting the
redirected call with said subscriber via the Internet access
server.
2. A method in accordance with claim 1 characterized in that upon
start up of said telephony application, said telephony application:
establishes a connection (14A, 15) to the telephony server,
requests the forwarding of calls to the subscriber to go to the
telephony server.
3. A method in accordance with claim 2 characterized in that said
telephony server upon completion of said connection receives the
identity of the subscriber and the IP address to the subscriber's
data terminal equipment (2).
4. A method in accordance with claim 3 characterized in that (a) an
incoming call to the subscriber, in consequence of said forwarding,
is forwarded to said telephony server, (b) that the telephony
server establishes a relation between the incoming call and the IP
address of the subscribers data terminal equipment, (c) that the
telephony server sends an alert to the subscriber's telephony
application via the Internet access server.
5. A method in accordance with claim 4 characterized in that in
response to said alert the subscriber instructs the telephony
server to take the call, and that the telephony server performs
said step of connecting the redirected call with the subscriber
using said relation.
6. A method in accordance with claim 4 characterized in that in
response to said alert the subscriber decides that the incoming
call shall be redirected to a call handling agent (19,20), and that
the telephony server initiates redirection of the incoming call to
the call handling agent using said relation.
7. A method in accordance with claim 3 wherein an outgoing call
from the subscriber initially is made in a manner known per se in
that the subscriber enters the number to call and requests the
telephony application to initiate the call characterized in that
the telephony application (11) requests the telephony server (10)
to initiate the call to the requested number, that the telephony
server selects an outgoing line an initiates the call in the public
network (3), that the called party answers the call and that voice
information is exchanged between the telephony server and the
telephony application as compressed audio transported over the IP
link and that the call is terminated and charged.
8. A method in accordance with claim 3 wherein the subscriber
requests the telephony application to withdraw characterized in
that the telephony application requests the call forwarding service
to be canceled.
9. A method in accordance with claim 3 characterized in that after
establishing said connection (15, 14a) the telephony server
initiates an authentication process the purpose of which is to
identify the subscriber and to receive the subscriber's own
telephone number which is to trigger forwarding to the telephony
server, thus allowing the subscriber to take calls to the
subscriber's own telephone while the subscriber is having the
Internet session at another terminal equipment connected to the
telephony server by other means than using the subscriber's own
telephone line.
10. A telephony server for providing the telephony service to an
Internet user, characterized by a central controller (27) connected
to an access handler (28), a voice compression and packetizing unit
(29) and an IP access controller (30), incoming and outgoing
telephone lines (31, 32) connected to the access handler, and lines
(33) connected to the IP access controller and adapted to be
connected to an Internet access server.
11. A telephony server in accordance with claim 10, characterized
by a fax handling unit.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to telecommunication in
general and to voice communication over the Internet in
particular.
PRIOR ART
[0002] The TCP/IP protocol, sometimes referred to as the `Internet
protocol`, was developed as a standard protocol to allow different
types of computers to exchange electronic mail and other files over
a network. The network using this protocol is known as the
`Internet` and has grown from its beginning when it linked military
and educational sites in the USA to become world-wide.
[0003] A new IEEE standard referred to as isoEthernet allows up to
96 two way voice channels to be present on a standard 10BaseT
Ethernet network without affecting any of the normal ethernet
traffic. The isoEthernet technology keeps packet data and real-time
information separated so voice and video are unaffected by data
traffic and vice versa.
[0004] The use of Internet for telephony is known and requires a
sound card mounted in a PC (personal computer), a microphone and a
pair of speakers connected to the sound card, and a telephony
application (software) that recognizes the sound card.
Bidirectional voice communication is possible between two telephony
applications.
[0005] The use of a LAN for telephony is known and requires a
telephony application running under WINDOWS on a PC which is
connected to a LAN (Local Area Network) or an ATM-LAN (Asynchronous
Transfer Mode). The user can make and receive telephone calls
to/from another PC or the public ISDN (Integrated Services Digital
Network), PSTN (Public Switched Telephone Network) or mobile
networks. Access between a private LAN and a public telephony
network is provided by a gateway.
RELATED TECHNIQUE
[0006] When a computer is connected to the Internet via a modem and
a subscriber line of the PSTN, it is not possible to place outgoing
calls or to take incoming calls on the line to which the modem is
connected.
[0007] This situation is also present when Internet is used for
telephony using the above described known technique with a PC
connected to the Internet via a modem, a PC mounted sound card and
a telephony application. The Internet user's ordinary home
telephone is blocked. An incoming call meets a busy tone and no
outgoing call can be placed.
[0008] A caller that dials, in the PSTN or the ISDN, the telephone
number associated with the modem line on which an Internet session
is taking place will hear a busy tone. Conversely, it is not
possible to place outgoing phone calls on a line to which a modem
is connected when the modem is engaged in an ongoing Internet
session.
[0009] Typically an Internet session is started by having the
computer to dial the telephone number to an Internet gate way. A
PPP (point-to-point protocol) connection or a SLIP (serial line
Internet protocol) connection is established between the computer's
modem and the Internet gateway when the Internet gateway answers
the call. The telephone line is used for this connection. A person
operating the computer starts an Internet session by running an
Internet application such as NETSCAPE. A session may comprise
sending e-mail, downloading a file, participate in a discussion by
exchanging information in writing, `surfing on the net` and many
other activities. During a session digital data is exchanged over
the line using the standard TCP/IP protocol (transmission control
protocol and Internet protocol). Information is exchanged between
the computer and the Internet in form of packets.
[0010] In a household an ongoing Internet session presents a
problem. Members of the family cannot place outgoing calls when the
line is occupied by the computer engaged in the Internet session.
During an Internet session the line will be marked as occupied when
there is an incoming call to the family.
[0011] An obvious solution to the above problem is to provide a
separate telephone line for the computer. In view of the
subscription costs for a line this solution is less feasible.
[0012] Japan Patent Abstract JP-7-170 288 (U.S. Patent Ser. No.
5,604,737) relates to a communication system comprising a local
area network (LAN) and a communication server connected to the LAN
and to a public switched telephone network (PSTN) over an access
line to a central office. The communication server allows
establishment of telephone calls between communication terminals on
the LAN and between communication terminals connected to the LAN
and telephones in the PSTN or in a local telephone network
connected to the communication server.
[0013] In the LAN each communication terminal is identified by a
unique statically determined adress. To handle telephone calls a
communication terminal is also associated with a telephone number.
This association is a static relation, stored in the communication
server. The telephone numbers of the communication terminals
connected to the LAN are in the PSTN statically attributed to the
communication server, which acts as a Private Branch Exchange
(PBX), forwarding incoming calls to the communication terminal
associated with the called extension number of an incoming
call.
[0014] The present invention differs from the Japanese Patent
Abstract in that the present invention does not use a LAN but a
dialed up connection. The telephony server is located at the modem
pool and not at the user. Temporary relations are used, both as
regards the relation telephone number/IP adress as well as the
telephone number relation established while a call forwarding
service is active.
SUMMARY OF THE INVENTION
[0015] One object of the present invention is to provide a method
allowing a subscriber, engaged in an ongoing Internet session over
an IP (Internet Protocol) link that uses a telephone line, to place
an outgoing call over the telephone line without disrupting the
Internet session.
[0016] Another object of the present invention is to provide a
method allowing a subscriber, engaged in an ongoing Internet
session over an IP link that uses a telephone line, to take an
incoming call that as destination has the telephone number
associated with the occupied line without disrupting the Internet
session.
[0017] Still another object of the invention is to afford a mobile
Internet user access to the user's own home telephone. In
particular the user shall be able to place and to take calls
from/to the home telephone while engaged in an Internet session
over a line of another telephone. In other words the user shall be
able to start an Internet session from any selected telephone in
the telephone network and to be able to take calls, which as
destination has the telephone number of the user's home telephone,
while engaged in an Internet session on the telephone line of said
selected telephone, thus enabling placed calls to be charged to the
user's own subscription.
[0018] The method in accordance with the invention is to redirect,
also referred to as call forwarding or call transfer, a call to a
subscriber engaged in an Internet session, to a telephony server
connected to the Internet gateway. In the telephony server the
speech of the calling party is compressed and packetized. From the
telephony server an IP link is established to the user via the
Internet gateway. Over this IP link compressed and packetized
speech is transferred.
[0019] In accordance with the invention the telephony application,
running on the PC having the IP session, in collaboration with the
telephony server activates and deactivates the call forwarding
service.
[0020] As mentioned above the telephone number to which incoming
calls to a subscriber engaged in an Internet session are forwarded
to the telephony server.
[0021] In accordance with another embodiment of the invention the
user, when accessing the telephony server, is subjected to an
authentication process the purpose of which is to verify the
identity of a user. An authorized user is allowed to activate call
forwarding a non-authorized user not. An authorized user will have
calls, which are directed to the user's home telephone number,
forwarded to the current location at which the user is having the
Internet session. In this manner the user is given mobility.
[0022] A further advantage achieved by the present invention is
that the telephony service can be implemented with no or minimal
changes to the existing telephony networks. Telephony service
providers offering the service in accordance with the invention can
integrate the inventive service nicely with a user's normal
subscription.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The invention and its merits will be described in connection
with the accompanying drawings, wherein
[0024] FIG. 1 is a block diagram of entities involved in an
Internet session; among these a telephony server in accordance with
the present invention; the telephony server handling an incoming
call to an Internet user from a telephone user,
[0025] FIG. 2 is a block diagram similar to FIG. 1; the telephony
server handling an incoming call in a slightly different way,
[0026] FIG. 3 is a block diagram similar to FIG. 1; the telephony
server handling an outgoing call from an Internet user to a
telephone user,
[0027] FIG. 4 is a block diagram similar to FIG. 1; the telephony
server handling a call between two Internet users,
[0028] FIG. 5 is a block diagram of the telephony server in
accordance with the invention, and
[0029] FIG. 6 is a block diagram similar to that of FIG. 1 showing
a management system providing the service remote controlled call
forwarding.
DETAILED DESCRIPTION OF EMBODIMENTS
[0030] In FIG. 1 a user A has a telephone 1 and a personal computer
2 connected to the public switched telephone network (PSTN) 3 via a
modem 4 and a subscriber line 5. Another user B has a telephone 6
connected to PSTN 6 via another subscriber line 7.
[0031] In FIG. 1 there is also shown an Internet access server 8,
in the following referred to as an IP access server, which is
connected to PSTN and to the Internet 9. The IP access server acts
as an Internet gateway between the PSTN and the Internet. A
telephony server 10 in accordance with the invention is connected
to the Internet access server 8 and to PSTN 3 and provides a
telephony service to users of the Internet.
[0032] The personal computer is provided with sound capabilities
and has a microphone and a speaker connected. In FIG. 1 a telephony
application 11 is shown by the telephone symbol 11 at the screen of
the computer's monitor 12.
[0033] The telephony application is software that runs on the PC
and that operates on the Internet, on the PSTN and on the sound
card and its attached speaker and microphone. The telephony
application allows bidirectional voice communication over the sound
card and its attached microphone and speaker. The telephony
application in conjunction with the computer's sound capabilities
can transform electrical voice signals from the microphone into
digitized and compressed audio signals that are packetized and
supplied to the modem and can conversely transform packets
containing digitized compressed audio signals into analogue
electrical signals which are supplied to the speaker. For example
the sound capabilities of the computer are realized by sound card
connected to a serial port of the computer. The audio signals of
the sound card are processed by the computer and are exchanged with
the modem via the IP protocol driver programs and the serial port
to which the modem is attached. The modem, in its turn, is
connected to the subscriber line 5.
[0034] The telephony server 10 is co-located with the IP access
server and is generally independent of the IP access server. Its
physical connections with the PSTN and the IP access server are not
shown in FIG. 1 for the sake of clarity. As an example the
telephony server is connected to the IP access server via a non
shown LAN, and to the PSTN/ISDN via an ISDN or PABX line interface.
Over the connections between the telephony server and the IP access
server speech and data information is transported using the IP
protocol. Over the connections between the telephony server and the
PSTN speech to and from users is transferred and signalling to and
from the PSTN takes place.
[0035] the moment it is assumed the user telephony application is
not running on the computer.
Application Start Up
[0036] In FIG. 1 user A has set up a PSTN connection 13 to the IP
access server using an Internet application (not shown) running on
the computer 2. The IP access server gives a unique IP address to
user A's computer. While the Internet session is active the modem
will block user A's telephone 1. The telephone can therefore not
access PSTN. On the PSTN connection 13 packets organized in
accordance with the IP protocol, in the following referred to as IP
packets, are sent to and from the IP access server and from there
out to Internet following the horizontal path indicated by the
dashed line 14. Dashed line 14 is in the following referred to as
an IP link. For illustration purposes only the IP link 14 is shown
to have a first section 14A between the modem and the IP access
server and a second section 14B from the IP access server to the
Internet. In reality it is not possible to distinguish the first
and second sections of the IP link 14.
[0037] Accordingly the horizontal dashed line 14 in FIG. 1
represents user A's Internet connection.
[0038] User A is thus having an Internet session and user A's
subscriber line is marked "busy" at the local switching office (not
shown) in the PSTN. Conventionally and prior to the present
application user B, when placing a call to A, would meet a busy
tone.
[0039] In accordance with the present invention user A starts the
telephony application 11. Next the telephony application logs on to
the telephony server. To this end the telephony application
establishes an IP link 14A, 15 to the telephony server 10. The IP
link 15 is using any of the connections (non shown) between the IP
access server and the telephony server. When the telephony
application logs on to the telephony server it passes user A's
telephone number as well as the IP adress of user A's computer to
the telephony server. The telephony server now establishes a
temporary relation between user A's telephony number and the
IP-adress of user A's computer. The temporary relation will last
for the duration of the telephony application session and is
released when the telephony application session ceases
[0040] Finally the telephony server activates, in the PSTN and on
behalf of user A, the service "call forwarding" and indicates as
call forwarding number the unique telephone number of the telephony
server. Calls to user A's telephone number will, in accordance with
the invention, be routed in the PSTN to the telephony server.
Incoming Call
[0041] User B wants to speak with user A over the telephone and
dials the telephone number to user A. PSTN detects that calls to A
should be forwarded to the forwarding number and therefore
redirects the call to the telephony server. The telephony server
receives an incoming call at an port 16. Accordingly a PSTN
connection 17 is established to the telephony server. Next the
telephony server, based upon the temporary relation between user
A's telephone number and the IP adress of user A's computer,
creates a relation between the incoming call and the IP address of
user A's computer. This relation is referred to as the second
relation and is different from' the previously mentioned temporary
relation. Various methods to this are described below in connection
with FIG. 6. Next the telephony server alerts user A of the
incoming call by sending an alert message over the IP link 15. The
alert message is formatted in accordance with the TCP/IP
protocol.
[0042] Depending on the facilities available at user A, user A may
now decide to (a) take the call or (b) request the telephony server
to redirect the call to a call handler or (c) reject the call.
[0043] In alternative (a) user A sends a request, over the IP
packet paths 14a, 15, to the telephony server to take the call. The
request is sent by the telephony application. The telephony server
connects port 16 with a voice compression and packetizing device,
shown in FIG. 5, which digitizes, compresses and packetizes B's
speech and sends it over the IP packet paths 15, 14A to user A.
Without disrupting the Internet session user A can now speak with
user B over the IP packet paths 14a, 15 and the PSTN connection 17
using the telephony application 11. The voice path is indicated by
the heavy dash dot line 18. Eventually the call is terminated. User
A has thus got a soft phone for communication with PSTN over an IP
path. The soft phone comprises the telephony application 11, the
microphone, the speaker and the PC's sound capabilities.
[0044] In FIG. 2 alternative (b) is shown. In response to the
alert, user A sends a request to the telephony server. The request
is sent by the telephony application and orders the telephony
server to take the incoming call and to connect it to a call
handling agent. The call handling agent is a distributed entity,
one part 19 thereof being part of or connected to the telephony
server, another part 20 thereof being connected to the called
user's computer. An example of a call handling agent is an
electronic secretary having voice prompting facilities, another
example is a voice mail box. An example of a service provided by
the call handling agent is redirection of the incoming call to
another telephone number or to another facility.
[0045] In alternative (c) the telephony server rejects the call
without answering it.
[0046] When the conversation between A and B is finished the call
is terminated. The telephony server releases the second relation
between the incoming call and IP address of the called user's
computer.
Outgoing Call
[0047] In FIG. 3 an outgoing call from user A is shown. It is
supposed user A has an ongoing IP session with the Internet and
that user A wants to place an outgoing call. As described above in
connection with start up of the telephony application the IP access
server has associated a unique IP address to user A's computer and
has set up IP packet paths 14A, 15 to the telephony server. User A
enters the telephone number to call on the keyboard of the personal
computer and requests the telephony application to initiate an
outgoing call. In response to said request the telephony
application in its turn requests the telephony server to place an
outgoing call to the requested number. Said latter request together
with the requested telephone number is sent to the telephony server
over the IP packet paths 14A, 15.
[0048] The telephony server selects an outgoing line to the PSTN
and dials the requested number. The called party answers. A PSTN
connection, symbolically shown at 17 in FIG. 3, is set up to the
called party, user B in the example. Next, speech information is
exchanged between the telephony server and the telephony
application via the IP access server using the IP packet paths 14a,
15. The voice path is labelled 18.
[0049] In FIGS. 1, 2 and 3 members of the family of user A can
place outgoing calls using the telephony application while there is
an ongoing IP session. They also can take incoming calls using the
telephony application while there is an ongoing IP session.
Typically a modem connection has a bandwidth of 28 kbit/s. Using
modern speech coding technique voice transmission requires a
bandwidth of only about 10 kbit/s. The rest of the bandwidth
available on the PSTN connection 13 can be used for other
simultaneously running Internet applications.
[0050] FIG. 4 illustrates an example where users A and B both have
a respective personal computer 2 and 21 respectively. Each computer
is provided with a respective telephony application 11 and 22. Both
users are engaged in a respective IP session. User B's IP session
is using an IP packet path 23 comprising two parts 23A and 23B.
Both users will therefore also have their respective call
forwarding service activated. Suppose user A wants to make an
outgoing call, using his telephony application, to user B. Using
the method for an outgoing call described above the telephony
server places an outgoing call, PSTN connection 24, to B using B's
telephone number. The PSTN will redirect the call to the telephony
server which receives the call at an port 25. The telephony server
creates a relation between the incoming call and the called user B
and alerts B over IP packet paths 26, 23B. When B decides to take
the call, the telephony server will send voice data from A,
digitalized, compressed and packetized, in IP packets to the IP
access server over the IP packet paths 26, 23B. This completes a
connection between A and B.
Service Termination
[0051] User A requests the telephony application to withdraw. In
response to the request the telephony application requests the
telephony server to cancel the call forwarding service. Next the
telephony server deactivates the call forwarding service in the
PSTN. The dynamic relation between user A's telephone number and
the IP adress of user A's computer is released.
[0052] FIG. 5 is a block diagram of the telephony server 10 in
accordance with the invention. It comprises a central controller
27, an access handler 28, a compression- and packetizing unit 29,
an IP access controller 30, incoming and outgoing subscriber lines,
31 and 32 respectively, connected to the PSTN network and a number
of lines 33 connected to the IP access server 8. Under control from
the central controller the access handler receives incoming calls,
places outgoing calls, handles the telephone numbers of the
telephony server, requests the PSTN network to activate and
deactivate the call forwarding service and provides connections to
the IP access server. The compression and packetizing unit converts
analogue speech signals into digital format, and vice versa, so
that they can be subjected to digital processing. The digitized
speech signals are sampled using conventional technique and are
subjected to compression using conventional speech compression
algorithms. Finally the sampled compressed digital signals are
organized into packets and sent to the IP access controller. The IP
access controller provides the packets with headers and tails and
controls the flow of IP packets to and from the telephony server
using the TCP (transmission control protocol), the IP (Internet
protocol) network layer protocol and the UDP (user datagram
protocol) protocol.
[0053] The lines 31, 32 are preferably digital lines such as ISDN
30B+D (Primary rate B) or a digital PABX line (Private Automatic
Branch telephone exchange). To the telephony server it does not
matter whether the telephones 1, 6 are of analogous or digital
type, because PSTN/ISDN will provide the proper type of signals to
the telephones. The telephony server must however unpacketize the
compressed speech and decompress it before it is sent as normal
speech information to the PSTN or the ISDN network.
Relating an Incoming Call to the Called Internet User
[0054] In a preferred embodiment of the invention the telephony
server has a unique telephone number which is used by many
different telephony applications. The telephony server must thus be
able to combine an individual incoming call with the IP address of
the called Internet user. As described above when an Internet user
logs on to the telephony server at start up of the telephony
application the IP-address associated with the user's computer is
dynamically linked to the user's telephone number in the telephony
server. This information is stored by the telephony server. The
telephony server will thus have a list of telephone
number/IP-address combinations.
[0055] To establish the correct relation between an incoming call
and the called Internet user the telephony server must be given the
destination of the incoming call from the incoming call itself.
Several methods are available depending on the capabilities of the
network transporting the incoming call. It should be remembered
that the incoming call is a call that has been forwarded to the
telephony server.
[0056] If the network supports the service called A-number
transmission, a service that presents to the called party the
telephone number of the calling party (using the internationally
adopted notation that A makes a call to B; A and B not being the
same identities as used in the examples given in the
specification), then the number presented as A-number identity to
the telephony server will be the telephone number that forwards the
call, referred to as the call forwarding number. In this case the
call forwarding number is the telephone number to the called user.
Accordingly the incoming call will present to the telephony server
the telephone number to the called Internet user. Given this number
the telephony server looks into its list. In the list it will find
a matching telephone number/IP-address combination. Thus a relation
is created between the incoming call and the called user's IP
address.
[0057] In the future it is foreseen, quite independently of the
present invention, to change the line protocol containing the
A-number identification so that it presents to the called party
both the real destination address and the address to which
forwarding is taking place.
[0058] An alternative method of establishing the relation between
an incoming call and the IP address of an Internet user is possible
if the telephony server is connected to the PSTN or ISDN via an
interface, such as a PABX interface, allowing for several numbers
to be associated with the telephony server. In this case the
telephony server will assign a unique telephone number to the user
when the user starts the telephony application, and will release
the assigned number when the telephony application is terminated.
The released telephone number can then be used by another user that
logs on to the telephony server. The relation between a user's IP
address and said selected number of the telephony server is stored
in a table.
[0059] For an incoming call, the destination number of the
telephony server to which the call is redirected is known to the
telephony server, and the corresponding IP address to the user's
telephone is derived from the above mentioned table.
Call Forwarding
[0060] As an example how the call forwarding service is activated
by the telephony server on behalf of an Internet user A the
telephony server uses the known service called remote controlled
call forwarding. How this is done is explained with reference to
FIG. 7. In FIG. 7 a management system 37 of the PSTN network has
connections 38 to the PSTN and TCP/IP connections 39 to the IP
access server 8. To activate the remote controlled call forwarding
service the telephony server sends the above mentioned request for
forwarding of calls to the telephony server using a TCP/IP
connection 39. The telephony server states the selected telephone
number and the Internet user's home telephone number. In response
to this request the management system activates the forwarding
service with respect to the user's home telephone number. To
deactivate the forwarding service the telephony server sends
another request to the management system.
[0061] Another method to activate and deactivate the remote
controlled call forwarding service is that the telephony server in
case of a PSTN network dials, or in case of an ISDN network signals
on the D channel, (1) an access code to the remote controlled call
forwarding service, (2) the selected number to the telephony
server, or the unique number to the telephony server, and (3) the
home telephone number of the Internet user. This method requires
that the line protocol of the PSTN or ISDN network supports that
the remote controlled call forwarding service can be activated and
deactivated from the telephony server. To activate and deactivate
the service the telephony server needs to signal a pass word to the
PSTN/ISDN network for security reasons.
[0062] Still another method to activate and deactivate the call
forwarding service is to request this service from the user's
computer before the user connects the computer to the Internet.
Mobility
[0063] In accordance with a modified embodiment of the invention
the telephony application, when establishing contact with the
telephony server, has to follow an authentication procedure, the
purpose of which is to establish the identity of the user and the
telephone number/telephone line from which the user is having the
ongoing Internet session. As an example the telephony server
prompts the user or the user's telephony application to give a
password and the telephone number at which the Internet session
takes place. In accordance with this modified embodiment user A can
have the IP session from any telephone line connected to the PSTN,
thus imparting mobility to user A, while calls to user A's home
telephone will be redirected to the site at which user A is having
the Internet session.
Modifications
[0064] In the above description user A has access to the Internet
access server via the modem and the public switched telephone
network PSTN. Within the realm of the present invention a user can
access the Internet access server via an integrated service digital
network ISDN or other available network such as a mobile telephone
network.
[0065] The telephony server can be equipped with a fax handling
unit. If user B sends a fax to user A while user A's telephone
number is redirected to the telephony server the telephony server
will receive the call. The telephony server probes the voice
channel for a modem tone that characterizes the transmission from a
fax machine. When said tone is detected the telephony server
redirects the call to its fax handling unit and informs user A of
an incoming fax. The fax handling unit establishes the connection
with the sending fax machine and receives the fax. The fax handling
unit stores the received fax as an image file. At a time suitable
for user A, user A retrieves the fax as a file over the IP link.
Using a conventional fax application the fax is displayed on user
A's PC or is printed on a printer connected to the PC. In the
alternative the fax handling unit can send the fax image file to
user A as an Email. In a similar fashion user A can send a fax
while the Internet session is active.
[0066] A computer connected to the ISDN network will have no modem
between its serial port and the ISDN terminal. The computer is
connected either directly or via a terminal adapter to ISDN.
[0067] The invention has been described in connection with a modem
that supports transmission of voice and data serially. Today there
are modern modems supporting DSVD (Digital Simultaneous Voice and
Data or digital SVD) technique. DSVD modems can transmit both voice
and data at the same time on the same line. If user A connects to
the IP access server from a DSVD modem and the IP access server
supports DSVD voice information between the telephony server and
user A can in the alternative be transferred over a voice channel
between the telephony server 10 and the IP access server 8, and
over the voice channel of the DSVD modem from the IP access server
to user A.
[0068] The computer's sound capabilities may be realized on the
computer's mother board in which case no separate sound card is
required.
[0069] In FIG. 2 users A and B are handled by the same IP-access
server and the same telephony server. In the alternative users A
and B are served by different IP access servers and different
telephony servers.
[0070] The telephony server has been described as being co-located
with the IP access server. By this is meant that the telephony
server shall have such good connections with the IP access server
that it can be regarded as standing in the same cabinet or the same
room as the IP access server although in reality it is standing at
a different place or in a different room.
[0071] The way in which call forwarding is activated and
deactivated by the telephony server may be varied and depend on the
capabilities of the existing telephone network. Instead of letting
the telephony server insruct the PSTN to ac-tivate/deactivate the
call forwarding service user A can do it.
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