U.S. patent application number 11/387942 was filed with the patent office on 2006-07-27 for system and method for provisioning virtual circuits in broadband access multiplexing elements.
Invention is credited to Thomas L. Georges, Ren-Wei Liou, Harry Tang, Marvin Jeffery Wilson.
Application Number | 20060165086 11/387942 |
Document ID | / |
Family ID | 36659175 |
Filed Date | 2006-07-27 |
United States Patent
Application |
20060165086 |
Kind Code |
A1 |
Wilson; Marvin Jeffery ; et
al. |
July 27, 2006 |
System and method for provisioning virtual circuits in broadband
access multiplexing elements
Abstract
A system for provisioning virtual circuits in broadband access
multiplexing elements is disclosed. The system manages an algorithm
that selects a unique virtual path identifier and virtual circuit
identifier for each new multiplexor input from a pool. The system
sends commands to connect each new input to the multiplexor output
based on the selected virtual path identifier and virtual circuit
identifier. The selected virtual path identifier and virtual
circuit identifier remain assigned to the input port even if the
input connection is later deleted.
Inventors: |
Wilson; Marvin Jeffery;
(Duluth, GA) ; Liou; Ren-Wei; (Dunwoody, GA)
; Georges; Thomas L.; (Roswell, GA) ; Tang;
Harry; (Atlanta, GA) |
Correspondence
Address: |
WITHERS & KEYS FOR BELL SOUTH
P. O. BOX 71355
MARIETTA
GA
30007-1355
US
|
Family ID: |
36659175 |
Appl. No.: |
11/387942 |
Filed: |
March 23, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10112558 |
Mar 28, 2002 |
|
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11387942 |
Mar 23, 2006 |
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Current U.S.
Class: |
370/395.2 |
Current CPC
Class: |
H04L 12/5601
20130101 |
Class at
Publication: |
370/395.2 |
International
Class: |
H04L 12/56 20060101
H04L012/56 |
Claims
1. A method for provisioning virtual circuits in broadband access
multiplexing elements, comprising: selecting a multiplexing element
input port for use determining if the selected input port has been
previously selected for use; if the input port has not been
previously selected, then assigning to the input port a virtual
path identifier and a virtual circuit identifier selected from a
pool of available virtual path identifiers and available virtual
circuit identifiers; and if the input port has been previously
selected, then assigning to the input port its previously assigned
virtual path identifier and virtual circuit identifier.
2. The method of claim 1, wherein the step of assigning to the
input port a virtual path identifier and a virtual circuit
identifier selected from a pool comprises removing the assigned
virtual path identifier and virtual circuit identifier from the
pool after it has been assigned.
3. The method of claim 1, further comprising the step of sending
commands to a multiplexing element management device to complete a
connection between the selected multiplexing element input port and
the multiplexing element output port using the virtual path
identifier and virtual circuit identifier assigned to each
port.
4. The method of claim 1, wherein said pool of available virtual
path identifiers and available virtual circuit identifiers is
unique to each multiplexing element.
5. The method of claim 1, wherein said broadband access
multiplexing element comprises a digital subscriber line access
multiplexor.
6. The method of claim 1, wherein said input port comprises a port
receiving a connection from one of a digital subscriber line modem
or a miniature remote access multiplexer.
7. The method of claim 1, wherein said pool of available virtual
path identifiers and available virtual circuit identifiers is
maintained by a network management system.
8. A computer readable medium having computer executable
instructions recorded thereon for performing the method recited in
claim 1.
9. A system for provisioning virtual circuits in broadband access
multiplexing elements, comprising: a processor operative to execute
computer executable instructions; and a memory having stored
therein computer executable instructions for performing the
following steps: selecting a multiplexing element input port for
use; determining if the selected input port has been previously
selected for use; if the input has not been previously selected,
then assigning to the input port a virtual path identifier and a
virtual circuit identifier selected from a pool of available
virtual path identifiers and available virtual circuit identifiers;
and if the input port has been previously selected, then assigning
to the input port its previously assigned virtual path identifier
and virtual circuit identifier.
10. A system for provisioning virtual circuits in broadband access
multiplexing elements, comprising: a means for selecting a
multiplexing element input port for use; a means for determining if
the selected input port has been previously selected for use; and a
means for assigning to the input port a virtual path identifier and
a virtual circuit identifier selected from a pool of available
virtual path identifiers and available virtual circuit identifiers
if the input has not been previously selected; and a means for
assigning to the input port its previously assigned virtual path
identifier and virtual circuit identifier if the input port has
been previously selected.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to telecommunications systems
and, more specifically, to systems and methods for provisioning
resources in a broadband network.
[0003] 2. Description of the Prior Art
[0004] Demand for in-home data and telephony services has grown
dramatically in recent years and is expected to continue to
increase. Accordingly, providers of data and telephony services
have sought to design and deploy broadband networks with increased
delivery capacity.
[0005] One broadband technology that has become particularly
popular is digital subscriber lines (DSL). DSL offers increased
data transfer rates and integrated telephony and data services
using the existing public switched telephone network (PSTN), which
previously was used exclusively for telephone voice
communications.
[0006] As the demand for DSL service has grown, service providers
have needed to build-out their infrastructure for providing DSL
service. In particular, service providers have needed to quickly
install large numbers of network elements devoted to providing DSL
service. For example, service providers have needed to install
large numbers of broadband access multiplexing elements, which
generally include digital subscriber line access multiplexors
(DSLAM's) and miniature remote access multiplexors (MINIRAM's).
Installing, managing, and administering these quickly expanding,
geographically distributed DSL networks has become increasingly
complex, time consuming, and expensive.
[0007] One aspect of DSL network maintenance that is very cost and
labor intensive is provisioning permanent virtual circuits (PVC's)
in broadband access multiplexing elements. PVC's are permanent,
"always on" connections between devices in the DSL network. A
physical transmission path may be divided into a certain number of
virtual paths. Each virtual path may be further divided into a
certain number of virtual channels. Each PVC may be identified by a
virtual path identifier (VPI) and a virtual channel identifier
(VCI). At a multiplexing element, PVC's may be connected using
VPI's and VCI's. Thus, it is necessary to assign a specific VPI and
a VCI to each of the multiplexor's input ports. This is often a
difficult task because multiplexors may often contain a very high
quantity of inputs, and the number of VCI's and VPI's available is
limited.
[0008] There are several existing methods for assigning a VPI and a
VCI to each multiplexor input. One existing scheme assigns a VPI
and a VCI to each input from an algorithm based on the rack, shelf,
card and port to which that input path is connected. However, this
scheme is ineffective because multiplexors often contain too many
racks, shelves, cards, and ports.
[0009] Another existing scheme selects a new VPI and VCI for each
"new" input. A "new" input is created each time a new subscriber
requests DSL service. For each new input, an available VPI and VCI
is selected from a pool of available VPI's and VCI's. When a VPI
and a VCI is selected for the new input they are removed from the
pool. If an existing subscriber wishes to have his or her service
discontinued, then an existing connection must be deleted. When an
existing connection is deleted the existing VPI and VCI are placed
back in the pool. However, the effectiveness of this scheme is
limited because attempts to delete a virtual circuit cross
connection are often unsuccessful. Thus, despite attempts to delete
it, a VPI and VCI may remain assigned to a given input even if that
input is not actually used by a subscriber. When a new subscriber
requests service, he or she may be assigned the same VPI and VCI as
the connection that the service provider had previously attempted
to remove. Therefore, the new subscriber's cross connection will
fail.
[0010] Thus, a need exists in the art for systems and methods for
provisioning virtual circuits in broadband access multiplexing
elements that are suitable for the high quantity of multiplexor
inputs and that eliminate the problem of service failure due to
unsuccessful cross connection deletion attempts.
SUMMARY OF THE INVENTION
[0011] Accordingly, systems and methods for provisioning virtual
circuits in broadband access multiplexing elements are disclosed.
Systems and methods in accordance with the invention are operable
in DSL networks comprising DSL line multiplexor devices such as for
example, DSLAM's, and element management systems (EMS's) for
managing the operation of these same multiplexor devices. As is
explained in detail below, a DSL network may comprise a large
number of EMS's, with each EMS having a large number of
multiplexors that it is dedicated to managing. The DSL network may
also comprise a network management system (NMS) that is responsible
for managing the entire network. The NMS manages individual network
elements by sending commands to the EMS dedicated to managing the
particular element.
[0012] When a new subscriber requests DSL service, an available
input port on a multiplexor is selected to serve as the line
termination port for the subscriber's line. The NMS determines if
the selected input port has been previously used. If the selected
input port has not been previously used, then the NMS assigns to
the input port a unique VPI and VCI selected from a pool of
available VPI's and VCI's. The pool is unique to each multiplexor
and is maintained by the NMS. The NMS then removes the selected VPI
and VCI from the pool. If the selected input port has been
previously used, then the NMS assigns to the input port its
previous VPI and VCI. The NMS then sends commands to the EMS to
connect the selected input port's assigned VPI and VCI to the
output VPI and VCI.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will be better understood after
reading the following detailed description of the presently
preferred embodiments thereof with reference to the appended
drawings, in which:
[0014] FIG. 1 is a high level diagram of an exemplary DSL
network;
[0015] FIG. 2 is a high level diagram of an exemplary DSL element
management network;
[0016] FIG. 3 is a block diagram of a computing device for use in a
system in accordance with an aspect of the invention; and
[0017] FIG. 4 is a flowchart of a method for provisioning virtual
circuits in broadband access multiplexing elements.
DETAILED DESCRIPTION
[0018] Systems and methods for provisioning virtual circuits in
broadband access multiplexing elements in accordance with the
invention are described below with reference to FIGS. 1-4. Those
skilled in the art will readily appreciate that the description
given herein with respect to those figures is for explanatory
purposes only and is not intended in any way to limit the scope of
the invention. Throughout the description, like reference numerals
will refer to like elements in the respective figures.
[0019] Generally, applicants have invented systems and methods for
provisioning virtual circuits in broadband access multiplexing
elements. When a new subscriber requests DSL service, an available
input port on a broadband access network multiplexing element such
as, for example, a DSLAM, is selected to serve as the line
termination port for the subscriber's line. The NMS determines if
the selected input port has been previously used. If the selected
input port has not been previously used, then the NMS assigns to
the input port a unique VPI and VCI selected from a pool of
available VPI's and VCI's. The pool is unique to each DSLAM and is
maintained by the NMS. The NMS then removes the selected VPI and
VCI from the pool. If the selected input port has been previously
used, then the NMS assigns to the input port its previous VPI and
VCI. The NMS then send commands to the EMS to connect the selected
input port's assigned VPI and VCI to the output VPI and VCI.
[0020] Prior to explaining the details of an illustrative
embodiment of the invention, it is useful to provide a description
of a suitable exemplary environment in which the invention may be
implemented.
Exemplary DSL Network Environment
1. Exemplary DSL Network
[0021] DSL is a technology that converts existing twisted-pair
telephone lines into access paths for multimedia and high-speed
data communications. DSL services promise to dramatically increase
the speed of copper wire based transmission systems without
requiring expensive upgrades to the local loop infrastructure. As
used herein, xDSL refers to the numerous variations of DSL
technology using the Bellcore acronyms such as ADSL (Asymmetric
DSL), HDSL (high bit-rate DSL), RADSL (rate-adaptive DSL), and the
like. New and improved versions of xDSL are in constant development
and the invention is not intended to be limited to any single
variation of the technology.
[0022] Most xDSL signals fall within the frequency range of 4 KHz
to 2.2 MHz, with the range of 0 to 4 KHz reserved for the
transmission of analog voice signals for plain old telephone
service (POTS). The theoretical maximum amount of bandwidth between
4 KHz and 2.2 MHz is almost 70 Mbps of digital data spectrum. In
practice however, only lab test conditions have ever reached higher
than 60 Mbps and currently available products typically use 2 Mbps
to 8 Mbps.
[0023] The different types of xDSL technologies may also be
categorized as either symmetric EC xDSL or asymmetric (FDM) xDSL. A
first class of EC xDSL includes Integrated Services Digital
Network. (ISDN), High-Bit-Rate DSL (HDSL), and Single-Line DSL
(SDSL). A second class of EC xDSL includes Asymmetric DSL (ADSL)
and Rate Adaptive DSL (RADSL). The modulation technologies employed
with the various types of xDSL include 2-binary 1-quaternary (2B1Q)
for ISDN and HDSL, carrierless amplitude phase modulation (CAP) for
HDSL, SDSL and RADSL, and discrete multi-tone modulation (DMT) for
ADSL and RADSL.
[0024] Generally, DMT divides the upstream and downstream bands
into smaller individual or discrete bands. The modems on either end
listen to these discrete bands as smaller channels within the main
upstream or downstream channel. Often, one of these smaller bands
will be disrupted by noise, rendering the information carried
within that band useless. Rather than toss away all the information
sent at that instant across the entire upstream or downstream band,
only that small part is lost and needs to be retransmitted.
[0025] With CAP, the overall amplitude or power of the signal is
modulated. The signal is not safeguarded against noise and often
suffers from lost information, which accounts in part for the lower
transmission speeds of CAP-based DSL technologies. With amplitude
modulation, there is also more loss over longer ranges. The
benefits of CAP over DMT are that it is simpler in design and
therefore cheaper, requires less power, and generates less heat.
Both power consumption and heat are serious factors when it comes
to housing many of these systems together (as in a central office).
DMT however, often provides the best results and maintains the full
bandwidth at its maximum range of 18,000 feet. CAP signals degrade
quickly after 10,000 feet.
[0026] Typical xDSL systems are implemented as follows. At the
customer premises a splitter is provided which separates the xDSL
signals (i.e., digital data signals) from the POTS analog voice
signals. The main purpose of the splitter is to shield ordinary
telephones from the high frequency xDSL signals that can have
disastrous effects on the telephone or human ear. The data line
from the splitter connects to an xDSL modem and the analog line
connects to the telephone. With xDSL Lite and some other product
models, there is no external splitter or it is combined into the
xDSL modem unit. An Ethernet line will usually link the xDSL modem
to the customer premises PC.
[0027] The twisted pair from the customer premises connects to an
xDSL access multiplexor such as, for example a DSLAM, typically
located at the incumbent local exchange carrier (ILEC) central
office (CO). The twisted pair from the customer premise may also
pass through a neighborhood wiring distribution frame, which is a
central point where the wire pairs from several customer premises
come together, and/or an ILEC remote terminal before reaching the
CO. Typically, a DSLAM is a multi-module unit that houses many
CO-side xDSL modems within a single shelf much like the analog
modern racks of today. At the DSLAM the voice and data lines are
split out along separate paths. The digital data signal goes into
either an ATM concentrator or an Internet Protocol router. The
analog voice signals are connected to the CO phone switch. Thus,
the digital data packets go through the router out to the Internet,
and the analog voice signals go through the phone switch and into
the public switched telephone network.
[0028] ADSL is one particularly promising and popular form of xDSL.
ADSL can transmit up to 6 Mbps to a subscriber, and as much as 832
kbps or more in both the downstream and upstream directions. Such
rates expand existing access capacity by a factor of 50 or more
without the need to install new wiring or cabling. An ADSL circuit
connects an ADSL modem on each end of a twisted-pair telephone
line, creating three information channels--a high speed downstream
channel, a medium speed duplex channel, depending on the
implementation of the ADSL architecture, and a POTS or ISDN
channel. The POTS/ISDN channel is split off from the digital modem
by filters, thus guaranteeing uninterrupted POTS/ISDN, even if ADSL
fails. The high speed channel ranges from 1.5 to 6.1 Mbps, while
duplex rates range from 16 to 832 kbps. Each channel can be
submultiplexed to form multiple, lower rate channels, depending on
the system.
[0029] ADSL modems provide data rates consistent with North
American and European digital hierarchies and can be purchased with
various speed ranges and capabilities. The minimum configuration
provides 1.5 or 2.0 Mbps downstream and a 16 kbps duplex channel;
others provide rates of 6.1 Mbps and 64 kbps duplex. Products with
downstream rates up to 8 Mbps and duplex rates up to 640 kbps are
currently available. ADSL modems also can accommodate ATM transport
with variable rates and compensation for ATM overhead, as well as
IP protocols. Downstream data rates depend on a number of factors,
including the length of the copper line, its wire gauge, presence
of bridged taps, and cross-coupled interference. Line attenuation
increases with line length and frequency, and decreases as wire
diameter increases.
[0030] FIG. 1 shows an exemplary ADSL based broadband access
architecture 100. In order for an IP enabled device (e.g., personal
computer 103 in home 102a) to establish a service session with a
source on the Internet 115, the IP enabled device first establishes
an access session with an Open Systems Interconnection (OSI) model
layer 2/3 communications element (e.g., router 114) in an Internet
service provider (ISP) network (e.g., ISP network 113) through an
asynchronous transfer mode (ATM) based broadband access network
(e.g., broadband access network 101) with a broadband access device
(e.g., DSL modem 104) connected to the local loop. (e.g., link
106a). An IP client (not shown) on the IP enabled device secures an
IP address from the ISP using Dynamic Host Configuration Protocol
(DHCP) from a DHCP server (not shown) in communication with the
ISP's router. The DHCP server temporarily allocates or leases a
unique IP address to the IP client. The IP client may now obtain IP
based services available on the ISP network and beyond by sending
and receiving packets to and from the ISP's router through the
broadband access network. Sources on the Internet 115 are reached
by utilizing a communications link between the ISP network and the
Internet 115 (e.g., communications link 117).
[0031] In addition to the layer 2 communications elements (e.g.,
asynchronous transfer mode (ATM) switches 108 and 109), layer 2/3
communications elements also form a part of broadband access
network 101. Specifically, a plurality of layer 2/3 communications
elements (e.g., ingress broadband gateways 120a-n) reside after
various layer 2 communications elements (e.g., ATM Switch 108)
lying near ingress points for access device IP traffic (e.g., IP
traffic from personal computer 103), and a plurality of layer 2/3
communications elements (e.g., egress broadband gateway 121a)
reside after layer 2 communications elements (e.g., ATM Switch 109)
lying near egress points for access device IP traffic destined for
ISP networks (e.g., ISP network 113) linked to broadband access
network 101. In exemplary network 100, ATM switch 108 may comprise,
for example, a Lucent CBX 500 multiservice WAN switch, and ATM
switch 109 may comprise, for example, a Lucent GX 550 multiservice
WAN switch. Ingress and egress broadband gateways 120, 121
comprise, for example, Nortel 5000 Broadband Service Nodes.
[0032] Each of the layer 2/3 communications elements in broadband
access network 101 supports the creation of layer 3 communications
sessions between various communications elements within and without
network 101 using layer 3 protocols such as IP. The layer 2/3
communications elements also support the creation of virtual layer
2 communications sessions or "virtual PVCs (vPVCs)" using one or
more of the following protocols: Point-to-Point Protocol (PPP) over
Ethernet (PPPoE), PPP over ATM (PPPoA), Layer 2 Tunneling Protocol
(L2TP), Point-to-Point Tunneling Protocol (PPTP), and/or Switched
Multimegabit Data Service (SMDS) Interface Protocol (SIP). A PVC is
a "permanent" virtual circuit and provides an "always on"
connection whether the subscribers is actively using it or not.
Thus, a series of three layer 2 virtual PVCs (e.g., vPVC1a 125a,
vPVC2a 126a, and vPVC3a 127a) extend from an access device (e.g.,
ADSL modem 104) to an ISP (e.g., ISP network 113) through broadband
access network 101 (versus having a single layer 2 PVC extending
from an access device to an ISP as in other broadband access
networks).
[0033] The first layer 2 vPVC (e.g., vPVC1a 125a) extends from an
access device (e.g., ADSL modem 103) to one of the ingress layer
2/3 communications elements (e.g., ingress broadband gateway 120a),
and is the only vPVC devoted exclusively to a single IP subscriber.
Typically the first layer 2 vPVC is a user authenticated PPP
session. In one embodiment of the network 101 the first layer 2
vPVC is a user authenticated PPPoE session where the IP enabled
device (or the operator thereof) supplies a username and domain
(e.g., "user1@domain1"). Based on the domain provided, the first
layer 2/3 communications element establishes a virtual layer 2
connection using L2TP over the remaining two layer 2 vPVCs to reach
the appropriate ISP and the ISP provides the IP enabled device an
IP address for obtaining IP based services. This model allows for
the creation of access sessions with different ISPs depending on
the domain provided by the IP enabled device. This model also
allows IP services to be billed to a particular user on a per
access session basis.
[0034] The second vPVC (e.g., vPVC2a 126a) extends from the
foregoing ingress layer 2/3-communications element (e.g., Ingress
Broadband Gateway 120a) to one of the egress layer 2/3
communications elements (e.g., Egress Broadband Gateway 121a).
Through the use of a tunneling protocol such as L2TP, PPP
aggregation occurs at the layer 2/3 ingress communications element
and the multiple PPP communications sessions between access devices
(e.g., access devices in homes 102b-n) served by the ingress layer
2/3 communications element are funneled into the second vPVC. The
third vPVC (e.g., vPVC3a 127a) extends from the foregoing egress
layer 2/3 communications element (e.g., Egress Broadband Gateway
121a) to the layer 2/3 communications element in the ISP network.
In this embodiment of the invention the layer 2/3 communications
element in the ISP network is an LNS capable router (e.g., layer
2/3 communications element 114). Again, through the use of a
tunneling protocol such as L2TP, PPP aggregation occurs at the
egress layer 2/3 communications element and the multiple PPP
communications sessions from multiple L2TP IBG tunnels are
concentrated onto a single L2TP tunnel by the egress broadband
gateway and are funneled into the third virtual PVC. The third
virtual PVC delivers a large (doubly aggregated) L2TP tunnel to the
LNS router 114 where the PPP sessions are terminated and IP packets
are once again routed normally.
[0035] As shown in FIG. 1, each twisted wire pair from customer
premises 102a-n housing an xDSL modem 104 connects to a multiplexor
device such as, for example DSLAM 107 or MiniRAM 140. Furthermore,
a connection from MiniRAM 140 terminates in DSLAM 107. In exemplary
network 100, DSLAM 107 may be, for example, an Alcatel 7300 DSL
Access Line Multiplexor. Generally, a cross connection must be
completed between the input ports of DSLAM 107 and the output port
of DSLAM 107. This connection is completed using the unique VPI's
and VCI's assigned to each input port and to the output port.
Systems and methods for provisioning VPI's and VCI's in broadband
access multiplexing elements are described below.
2. Provisioning Virtual Circuits in Broadband Access Multiplexing
Elements
[0036] FIG. 2 depicts an illustrative DSL network management system
200 in which systems and methods provisioning virtual circuits in
broadband access multiplexing elements in accordance with the
invention may operate. As shown, system 200 comprises at least one
network management system (NMS) 202, a plurality of element
managers (EMSs) 201a-201m, DSLAMs 107a-n forming a portion of
broadband access network 101, MiniRAMs 140a-n also forming a
portion of broadband access network 101, and a plurality of
communication paths or links 202a-n, 203a-m, 204a-m between the
NMS, EMSs, DSLAMs, and MiniRAMs. NMS 202 coordinates the operation
of nodes, elements, objects, cards, physical links, equipment, and
the like, within network management system 200. DSLAMs 107a-n and
MiniRAMs 140a-n comprise managed elements within network management
system 201. EMSs 201a-m comprise intermediaries between NMS 202 and
the broadband network elements including DSLAMs 107a-n and MiniRAMs
140a-n. As an intermediary, the EMSs interpret messages, such as
simple network management protocol (SNMP) messages, to and from
nodes in network management system 201. In one embodiment of the
invention communication between the NMS 202 and the EMSs 201a-m is
via X.25, serial, TCP/IP, or UDP/IP connection while communication
between the EMSs 201a-m and the DSLAMs 107a-n is via SNMP over
UDP/IP. In an illustrative embodiment of system 200, NMS 202
comprises, for example, an Alcatel 5620 Network Manager, EMSs
201a-m comprise, for example, Alcatel 5526 Access Management
Systems, DSLAMs 107a-n comprise, for example, Alcatel 7300 DSL
Subscriber Access Platform.
[0037] NMS 202 manages the algorithm that provisions virtual
circuits in DSLAM's 107 a-n. NMS 202 selects a VPI and VCI for each
new input to DSLAM's 107 a-n and sends commands to EMS's 201 a-m to
connect the VPI and VCI of each new input to DSLAM's 107 a-n to the
output of DSLAM's 107 a-n.
[0038] NMS 202 may be implemented on a generic computing system
such as is shown in FIG. 3. As shown, computing device 320 includes
processing unit 322, system memory 324, and system bus 326 that
couples various system components including system memory 324 to
the processing unit 322. The system memory 324 might include
read-only memory (ROM) and random access memory (RAM). The system
might further include hard-drive 328, which provides storage for
computer readable instructions, data structures, program modules
and other data. A user may enter commands and information into the
computer 320 through input devices such as a keyboard 340 and
pointing device 342. A monitor 344 or other type of display device
is also connected to the system for output. Communications device
343, which may be for example a TCP/IP enable device, provides for
communications in system 200. Processor 322 can be programmed with
instructions to interact with other computing systems so as to
perform the algorithms described below with reference to FIG. 4.
The instructions may be received from network 200 or stored in
memory 324 and/or hard drive 328. Processor 322 may be loaded with
any one of several computer operating systems such as Windows NT,
Windows 2000, Linux, and the like. Those skilled in the art
recognize that while NMS 202 is illustrated as a single desktop
computing system, a network of computing systems and/or other
computing devices such as for example, laptop and handheld
computing devices might be employed.
[0039] FIG. 4 is a flowchart of a method for provisioning virtual
circuits in broadband access multiplexing elements. When a new
subscriber requests DSL service, NMS 202 selects an available input
port on one of DSLAM's 107 a-n to serve as the line termination
port for the subscriber's line at step 410. At step 412, NMS 202
determines if the selected input port has been previously used. If
the selected input port has not been previously used, then, at step
414, NMS 202 assigns to the input port a unique VPI and VCI
selected from a pool of available VPI's and VCI's. The pool is
unique to each DSLAM 107 a-n and is maintained by NMS 202. At step
416, NMS 202 removes the selected VPI and VCI from the pool.
[0040] If the selected input port has been previously used, then,
at step 418, NMS 202 assigns to the input port its previous VPI and
VCI. At step 420, NMS 202 sends commands to dedicated EMS 201 a-m
to complete a connection between the selected DSLAM input and the
DSLAM output.
[0041] If an existing subscriber's DSL service is canceled, the
subscriber's connection is deleted. However, the VPI and VCI of the
subscriber's input port remained assigned to that port and are not
placed back in the pool of available VPI's and VCI's. Thus, a new
subscriber's line on a different input port cannot be assigned the
same VPI and VCI as the deleted connection. This eliminates the
problem of service failure due to unsuccessful cross connection
deletion attempts.
[0042] Thus, systems and methods for provisioning virtual circuits
in broadband access multiplexing elements have been disclosed.
These novel systems and methods comprise selecting a specific VPI
and VCI for each new multiplexing element input from a pool of
available VPI's and VCI's. Furthermore, these systems and methods
eliminate the problem of service failure due to unsuccessful cross
connection deletion attempts because a permanent VPI and VCI is
assigned to each input port of the multiplexing element.
[0043] Those skilled in the art understand that computer readable
instructions for implementing the above-described processes, such
as those described with reference to FIG. 4, can be generated and
stored on one of a plurality of computer readable media such as a
magnetic disk or CD-ROM. Further, a general purpose computer such
as that described with reference to FIG. 3 may be arranged with
other similarly equipped computers in a network, and may be loaded
with computer readable instructions for performing the above
described processes. Specifically, referring to FIG. 3,
microprocessor 322 may be programmed to operate in accordance with
the above-described processes.
[0044] While the invention has been described and illustrated with
reference to specific embodiments, those skilled in the art will
recognize that modification and variations may be made without
departing from the principles of the invention as described above
and set forth in the following claims. For example, while the
invention has been described in connection with provisioning of
virtual circuits in DSLAM's, the systems and methods may be
employed to plan other types of DSL multiplexing devices as well.
Accordingly, reference should be made to the appended claims as
indicating the scope of the invention.
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