The present invention relates generally to a digital subscriber line access multiplexer (DSLAM), and more particularly, to systems and methods for automatically configuring cross-connections in a DSLAM.
Digital subscriber line (DSL) technologies have become a widely-used solution for providing high bit rate transmission over the existing copper wire infrastructure, known as the “subscriber loop.” DSL technologies dramatically improve the bandwidth of the existing analog telephone system. DSL enhances the data capacity of the existing copper wire that runs between the local telephone company switching offices and most homes and offices. The bandwidth of the wire is limited to approximately 3,000 Hz due to its primary use as a voice telephone system. While the wire itself can handle higher frequencies, the telephone switching equipment is designed to cut-off signals above 4,000 Hz to filter noise off the voice line. DSL enables high-speed data traffic from a service provider network, such as an ATM network, to be provided on the existing wires with voice traffic.
In order to provide DSL service, a digital subscriber line access multiplexer (DSLAM) is employed at the local telephone company central office or digital loop carrier (DLC) to separate the voice-frequency traffic provided by the public-switched telephone network (PSTN) from the high-speed data traffic service provided by the network service provider. A DSLAM concentrates the high-speed data traffic and routes it to subscribers on twisted-pair wires, referred to as a local loop. Many DSLAMs are designed to work with ATM networks.
Generally, a DSLAM includes an uplink interface, a switch concentration module (SCM), a backplane interface, and multiple line cards. High-speed data traffic from an ATM network is received by the uplink interface via multiple data communications channels. The high-speed data traffic is then transmitted to the SCM where it is transmitted to the backplane interface. The backplane interface provides the high-speed data traffic to multiple DSL ports in the line cards for subsequent delivery to subscribers.
As will be described in more detail below, in order to establish an ATM connection through the DSLAM, each node must be provisioned with matching ATM virtual channel information or virtual path identifier (VPI)/virtual circuit identifier (VCI) addresses. With existing DSLAMs, for each connection through the DSLAM, a VPI/VCI address must be configured on each node to match the VPI/VCI addresses corresponding to the data communications channels received from the external ATM network. This manual configuration of multiple VPI/VCI addresses within the DSLAM is very time consuming and costly.
Thus, a heretofore unaddressed need exists in the industry to address these aforementioned deficiencies and inadequacies by automatically configuring ATM cross-connects in a DSLAM between a plurality of digital subscriber line channels and a plurality of data communications channels provided from an ATM service provider.
The present invention provides a system and method for automatically configuring ATM cross-connects in an ATM-based switch between a plurality of network-side communications channels provided from an ATM network and a plurality of user-side communications channels associated with a plurality of user ports.
Briefly described, in architecture, the switch comprises a means for receiving a plurality of network-side communications channels, a means for receiving a plurality of user-side communications channels, and a means for automatically configuring a plurality of cross-connects between the plurality of network-side communications channels and the plurality of user-side communications channels. The means for automatically configuring the plurality of cross-connects may comprise a means for obtaining a default logical VPI/VCI address associated with the plurality of network-side communications channels, a means for defining a first plurality of unique logical VPI/VCI addresses based on a predefined set of rules for incrementing logical VPI/VCI addresses, each of the first plurality of unique logical VPI/VCI addresses associated with one of the plurality of user-side communications channels, a means for determining a second plurality of unique logical VPI/VCI addresses based on the default logical VPI/VCI address and the predefined set of rules, and a means for creating signal connectivity between the plurality of network-side communications channels and the plurality of user-side communications channels by linking the first and second unique logical VPI/VCI addresses. The switch may further comprise a means for detecting a user port, the user port associated with one of a portion of the plurality of user-side communications channels, a means for specifying one of the first and second plurality of unique logical VPI/VCI addresses as a base logical VPI/VCI address for each of a plurality of types of channels, a means for associating each type of channel for the user port with one of the first plurality of unique logical VPI/VCI addresses.
The present invention can also be viewed as providing methods for automatically configuring a plurality of cross-connects in an ATM-based switch between a plurality of network-side communications channels and a plurality of user-side communications channels.
Briefly, one such method involves (1) obtaining a default logical VPI/VCI address associated with the plurality of network-side communications channels, (2) defining a first plurality of unique logical VPI/VCI addresses based on a predefined set of rules for incrementing logical VPI/VCI addresses, each of the first plurality of unique logical VPI/VCI addresses associated with one of the plurality of user-side communications channels, (3) determining a second plurality of unique logical VPI/VCI addresses based on the default logical VPI/VCI address and the predefined set of rules, and (4) creating a plurality of cross-connects between the plurality of user-side communications channels and the plurality of network-side communications channels by linking the first and second unique logical VPI/VCI addresses and defining the plurality of cross-connects as being in an autodown state. The method may further involve (5) detecting a plurality of user ports, each of the plurality of user ports associated with one of a portion of the plurality of user-side communications channels, (6) specifying one of the first and second plurality of unique logical VPI/VCI addresses as a base logical VPI/VCI address for each of a plurality of types of channels, (7) associating each type of channel for each user port with one of the first plurality of unique logical VPI/VCI addresses, and (8) changing the state of each of the plurality of cross-connects corresponding to each of the first plurality of unique logical VPI/VCI addresses associated with each type of channel for each user port to an up state.
The present invention can also be viewed as a computer-readable medium having a computer program for use by an ATM switch for automatically configuring a plurality of cross-connects between a plurality of network-side communications channels and a plurality of user-side communications channels. The computer-readable medium may include the steps of the methods of the present invention as an ordered listing of executable instructions for implementing logical functions related to automatically configuring the ATM cross-connects. The list of executable instructions for automatically configuring the ATM cross-connects, which are embodied in the computer-readable medium, may be used by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions.
Other systems, methods, features, and advantages of the present invention will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages included within this description, be within the scope of the present invention, and be protected by the accompanying claims.
The invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Having summarized the invention above, reference is now made in detail to the description of the invention as illustrated in the drawings. While the invention will be described in connection with these drawings, there is no intent to limit it to the embodiment or embodiments disclosed. On the contrary, the intent is to cover all alternatives, modifications and equivalents included within the spirit and scope of the invention as defined by the appended claims.
I. System Overview
As described in more detail below, service provider network 32 may be a cell-based network, such as an ATM network.
DSL system 20 enables a residential subscriber 22 and/or a commercial subscriber 24 to receive traditional voice-frequency services, as well as, high-speed data services over the same DSL loop 26. A DSL loop 26 is a traditional twisted-pair of copper wires that extends between central office 28 and a residential subscriber 22 and/or a commercial subscriber 24. Traditional voice-frequency services are provided by central office 28 via PSTN 30, while high-speed data services are provided via service provider network 32.
Residential subscribers 22 may be any residential entity having a twisted-pair copper connection from their premises to a central office 28. Commercial subscribers 24 may be any commercial entity, such as, for example, a business, a government agency, a hospital, a school, a university, or any other entity having a twisted-pair copper connection from their premises to a central office.
In order to enable DSL-based services, residential subscribers 22 employ at their premises a filter 34, a telephone 36, a DSL remote transceiver unit 38, and a computer 40. Commercial subscribers 24 may employ at their premises a filter 34, a telephone 36, a DSL remote transceiver unit 38, a network hub 41, a computer 40, and a workstation 42. Although
Filter 34 may be any standard plain old telephone service (POTS) splitter or any similar device capable of separating voice-frequency traffic from high-speed data traffic provided on a DSL loop 26 carrying both. Filter 34 is coupled to DSL loop 26. Tn operation, filter 34 receives voice-frequency traffic and high-speed data traffic as input from DSL loop 26 and provides the voice-frequency traffic to telephone 36 and the high-speed data traffic to DSL remote transceiver unit 38. Telephone 36 may be any conventional or future telephone or any similar device capable of converting sounds, such as voice, into analog data and transmitting the analog data over a DSL loop 26. DSL remote transceiver unit 38 functions as a DSL modem that provides the high-speed data traffic to computer 40. In the commercial subscriber environment, DSL remote transceiver unit 38 is coupled to a network hub 41, which supports a network of computers 40 and workstations 42. Computer 40 and workstation 42 may be any computer capable of receiving high-speed data traffic from a DSL loop 26. Those of ordinary skill in the art should understand that, although telephone 36 and computer 40 and workstation 42 are represented by different elements in
In accordance with the systems and methods of the present invention, DSL system 20 may provide any of a number of DSL-based services to a residential subscriber 22 and/or a commercial subscriber 24 via DSL loop 26. For example, DSL system 20 may provide high-bit-rate digital subscriber line (HDSL) services. HDSL provides T1data rates of 1.544 Mbits/sec over DSL loops 26 that are up to 3.6 kilometers in length. Generally, HDSL is a T1service that requires no repeaters, but does use two DSL loops 26. In HDSL, voice telephone services cannot operate on the same DSL loop 26. HDSL services are generally not used for residential subscribers 22, but instead are used by the operator of central office 26 as feeder lines, interexchange connections, Internet servers, or private data networks to commercial subscribers 24.
DSL system 20 may also provide symmetrical digital subscribe line (SDSL) services. SDSL is a symmetrical, bi-directional DSL service that is basically the same as HDSL but operates on one twisted-pair wire. It can provide data rates up to the T1 rate of 1.544 Mbits/sec, and it operates above the voice frequency, so voice and data can be carried on the same wire.
DSL system 20 may also provide asymmetrical digital subscriber line (ADSL) services. ADSL is the most common DSL service. It is an asymmetrical technology, meaning that the downstream data rate is much higher than the upstream rate. This type of service works well for providing typical Internet services to residential subscribers 22. ADSL operates in a frequency range that is above the frequency range of voice services, so the two systems can operate over the same subscriber cable.
DSL system 20 may also provide very high-bit-rate digital subscriber line (VDSL) services. VDSL is basically ADSL at much higher data rates. It is asymmetrical and thus has a higher downstream rate than upstream rate. VDSL service can be used on the same DSL loop 26 as the voice telephone network and ISDN. The upstream rates are from 1.6 Mbits/sec to 2.3 Mbits/sec.
DSL system 20 may also provide rate-adaptive digital subscriber line (RADSL) services. This service is similar to ADSL, but it has a rate-adaptive feature that will adjust the transmission speed to match the quality of DSL loop 26 and the length of DSL loop 26. A line-polling technique is used to establish a connection speed when the line is first established.
It should be understood by one of ordinary skill in the art that the systems and methods of the present invention are not dependent on or limited by the type of DSL service provided to residential subscribers 22 and/or commercial subscribers 24. These are merely examples of common DSL services that may be implemented.
In operation, high-speed data traffic from service provider network 32 is received at central office 28 by DSLAM 44 via communications channels 50. Voice-frequency traffic is received at central office 28 by telephone switch 46 via communications channels 52. As described above, DSL system 20 provides both the voice-frequency traffic and the high-speed data traffic from central office 28 to residential subscribers 22 and/or commercial subscribers 24 via DSL loops 26. DSLAM 44 enables the high-speed data traffic to bypass telephone switch 46. DSLAM 44 concentrates the high-speed data traffic and routes it to main distribution frame 48. Main distribution frame 48 receives the high-speed data traffic from DSLAM 44 and the voice-frequency traffic from telephone switch 46 and provides both types of traffic to communications channels 54 for subsequent delivery to residential subscribers 22 and commercial subscribers 24.
DSLAM 44 may be a DSLAM or some other type of access multiplexer. As will be described in detail below, DSLAM 44 may be a general purpose ATM switch.
II. DSLAM Components
Uplink interface 56 may be any type of interface to a wide-area transmission medium, such as a fiber-based (OC3), coaxial (DS3), or any other known or future type of wide-area transmission medium.
Backplane interface 60 may be a proprietary interface to line cards 62. In alternative embodiments, backplane interface 60 may be any type of interface to a wide-area transmission medium, such as a fiber-based (OC3), coaxial (DS3), or any other known or future type of wide-area transmission medium.
Each line card 62 includes a plurality of DSL ports 64. Each DSL port 64 corresponds to a DSL loop 26 connected to a residential subscriber 22 or a commercial subscriber 24.
In operation, high-speed data traffic from service provider network 32 (
III. ATM Service Provider Network
Referring to
ATM data is transmitted through an ATM network as 53-byte cells.
IV. Switch Concentration Module
As described above, in the preferred embodiment of the present invention, service provider network 32 is an ATM network. A fundamental concept of ATM is that switching occurs based upon the VPI/VCI fields of each cell. Switching done on VPI 74 only is called a VPC, while switching done on both the VPI 74 and VCI 76 is called a VCC.
Referring again to
At block 104, a default logical VPI/VCI address is obtained, which may be associated with communications channels 50 on uplink interface 56 (
At block 106, a first plurality of unique logical VPI/VCI addresses are defined based on a predefined set of rules for, incrementing logical VPI/VCI addresses, which will be described below. The first plurality of unique logical VPI/VCI addresses may be associated with communications channels 54 on backplane interface 60 (
At block 108, a second plurality of unique logical VPI/VCI addresses are determined based on the default logical VPI/VCI address and the predefined set of rules. The second plurality of unique logical VPI/VCI addresses may be associated with communications channels 50 and uplink interface 56.
At block 110, cross-connects are created between communications channels 50 and 54 by linking the first and second unique logical VPI/VCI addresses. Each of the cross-connects may be initialized to an autodown status. For example, in all known systems and methods, the cross-connects are typically administratively in an up or down status. In accordance with the systems and methods of the present invention, the automatically generated cross-connects are initialized to autodown, which signifies that the cross-connect has been automatically generated and does not have an association with a DSL port 64 or line card 62 (
At blocks 112 and 114, a line card 62 is detected and information is received from line card 62. In the preferred embodiment, the information relates to (1) a slot number corresponding to DSL ports 64, (2) the number of DSL ports 64 associated with the line card 62, (3) the number of types of channels 54 (
Block 116 specifies that for each type of channel indicated by line card 62, the following steps are performed. At block 118, one of the first and second plurality of unique logical VPI/VCI addresses are specified as a base logical VPI/VCI address for each channel based on the information from line card 62.
At block 120, each type of channel 54 for each DSL port 64 is associated with one of the first plurality of unique logical VPI/VCI addresses. At block 122, the state of each cross-connect corresponding to each of the first plurality of unique logical VPI/VCI addresses associated with each type of channel for each DSL port 64 is changed to up and traffic on each cross-connect is bound to the traffic profile specified by line card 62.
For example, a line card 62 in slot #3 may call for one channel 54 with 24 DSL ports 64. Line card 62 may also call for unspecified bit rate (UBR) packet-based service. Based on this information, a base logical VPI/VCI address corresponding to VPI=0 and VCI=32 may be specified. Then the status of cross-connects corresponding to VPI=0 and VCI=32 through VPI=0 and VCI=55 are changed to up and the traffic on each is bound to UBR.
For a second example, a line card 62 in slot #8 may call for one channel 54 with 16 DSL ports 64 for carrying unspecified bit rate (UBR) packet traffic and another channel for carrying variable bit rate (VBR) voice traffic. Based on this information, a base logical VPI/VCI address corresponding to VPI=0 and VCI=32 may be specified for the packet channel and another corresponding to VPI=1 and VCI=32 may be specified for the voice channel. Then the cross-connects corresponding to VPI=0 and VCI=32 through VPI=0 and VCI=55 are allocated and the status of cross-connects corresponding to VPI=0 and VCI=32 through VPI=0 and VCI=47 are changed to up and the traffic on each is bound to UBR. The cross-connects corresponding to VPI=1 and VCI=32 through VPI=1 and VCI=55 are also allocated and the status of cross-corresponding to VPI=1 and VCI=32 through VPI=1 and VCI=47 are changed to up and the traffic on each is bound to VBR.
Although in the embodiment of SCM 58 described with respect to
Management software 100 may be implemented in hardware, software, firmware, or a combination thereof. In the preferred embodiment, management software 100 is implemented in software or firmware that is stored in a memory and that is executed by a suitable instruction execution system, such as central processing unit 86. If implemented in hardware, as in an alternative embodiment, management software 100 may be implemented with any or a combination of the following technologies, which are all well known in the art: a discrete logic circuit(s) having logic gates for implementing logic functions upon data signals, an application specific integrated circuit (ASIC) having appropriate combinational logic gates, a programmable gate array(s) (PGA), a field programmable gate array (FPGA), etc.
The flow charts of
In one embodiment, management software 100 includes an uplink interface data module 130, cross-connect data module 132, backplane interface data module 134, VCL data module 136, a line card data module 138, an auto-configuration data module 140, and a DSL port data module 142 (
Line card data module 138 may include information related to line cards 62, which may be received from backplane interface 60.
DSL port data module 142 may include information related to DSL ports 64 for line cards 62.
Backplane interface data module 134 may include information related to backplane interface 60, such as identifiers for each of the links for communications channels 54 in backplane interface 60 and VPI/VCI pairs for each channel associated with each of the links.
Uplink interface data module 130 may include information related to uplink interface 56, such as identifiers for each of the links for communications channels 50 in uplink interface 56 and VPI/VCI pairs for each channel associated with each of the links.
Cross-connect data module 132 may include information defining a plurality of cross-connects between communications channels 54 and 50.
a–14c illustrate a cross-connection table 210 which may be used for implementing another portion of management software 100 in
For example, in the preferred embodiment, values 212 and 214 may be determined based on the following equation:
VCL data module 136 may include information associated with values 212 and 214 and actual VPI/VCI addresses associated with communications channels 50.
Auto-configuration data module 140 may include information related to a default logical VPI/VCI address associated with the VPI!VCI addresses for communications channels 50.
At block 262, a default logical VPI/VCI address is obtained, which may be associated with the communications channels corresponding to ATM node 252. The default logical VPI/VCI address may be stored within management software 100 in memory 88 or received from user interface 92.
At block 264, a first plurality of unique logical VPI/VCI addresses are defined based on a predefined set of rules for incrementing logical VPI/VCI addresses, which will be described below. The first plurality of unique logical VPI/VCI addresses may be associated with the communications channels associated with user-side ports 254.
At block 266, a second plurality of unique logical VPI/VCI addresses are determined based on the default logical VPI/VCI address and the predefined set of rules. The second plurality of unique logical VPI/VCI addresses may be associated with the communications channels corresponding to ATM node 252.
At block 268, cross-connects are created between the communications channels provided from ATM node 252 and the communications channels received by user-side ports 254 by linking the first and second unique logical VPI/VCI addresses. Each of the cross-connects may be initialized to an autodown status, which signifies that the cross-connect has been automatically generated and does not have an association with a particular user-side port 254.
At block 270 a user-side port 254 is detected. Block 272 specifies that for each type of channel indicated in the system, the following steps are performed. At block 274, one of the first and second plurality of unique logical VPI/VCI addresses are specified as a base logical VPI/VCI address for each type of channel.
At block 276, each type of channel for each communications channel associated with user-side ports 254 is associated with one of the first plurality of unique logical VPI/VCI addresses. At block 278, the state of each cross-connect corresponding to each of the first plurality of unique logical VPI/VCI addresses associated with each type of channel for each communication channel associated with user-side ports 254 is changed to an up status.
Management software 100, which comprises an ordered listing of executable instructions for implementing logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a “computer-readable medium” can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable medium can be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (a nonexhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic), a random access memory (RAM) (electronic), a read-only memory (ROM) (electronic), an erasable programmable read-only memory (EPROM or Flash memory) (electronic), an optical fiber (optical), and a portable compact disc read-only memory (CDROM) (optical). Note that the computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory.
It should be emphasized that the above-described embodiments of the present invention, particularly, any “preferred” embodiments, are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiment(s) of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of this disclosure and the present invention and protected by the following claims.
This application is related to U.S. Provisional Application entitled “Automatic Cross Connect Configuration in a DSLAM and Extensions for Class of Service and Scaling,” filed on Oct. 2, 2000 and accorded Ser. No. 60/237,148, which is hereby incorporated by reference, and to U.S. Provisional Application entitled “Systems and Methods for Automatically Configuring Cross-Connections in a Digital Subscriber Line Access Multiplexer (DSLAM),” filed on Dec. 1, 2000 and accorded Ser. No. 60/250,494, which is hereby incorporated by reference.
Number | Name | Date | Kind |
---|---|---|---|
6081517 | Liu et al. | Jun 2000 | A |
6084881 | Fosmark et al. | Jul 2000 | A |
6130879 | Liu | Oct 2000 | A |
6141339 | Kaplan et al. | Oct 2000 | A |
6349096 | Liu et al. | Feb 2002 | B1 |
6490273 | DeNap et al. | Dec 2002 | B1 |
6493348 | Gelman et al. | Dec 2002 | B1 |
6529479 | Suzuki | Mar 2003 | B1 |
6546089 | Chea, Jr. et al. | Apr 2003 | B1 |
6574313 | Chea, Jr. et al. | Jun 2003 | B1 |
6643253 | Smith | Nov 2003 | B1 |
6661795 | Adas et al. | Dec 2003 | B1 |
6667971 | Modarressi et al. | Dec 2003 | B1 |
6680904 | Kaplan et al. | Jan 2004 | B1 |
6711162 | Ortega et al. | Mar 2004 | B1 |
6714516 | Todd | Mar 2004 | B1 |
6771763 | Hagirahim et al. | Aug 2004 | B1 |
Number | Date | Country | |
---|---|---|---|
20010015978 A1 | Aug 2001 | US |