Method and apparatus for multiplexing of multiple users on the same virtual circuit

• US 6,345,051 B1
• Filed: 02/18/1998
• Issued: 02/05/2002
• Est. Priority Date: 02/18/1997
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Gupta, Dev Vrat, Lo, John, Cao, Carlos, Baker, Lee
• Primary Examiner(s): Olms, Douglas
• Assistant Examiner(s): HOM, SHICK C
• Application Number:
  US09/025,177
• Time in Patent Office: 1,448 Days
• Field of Search: 370/237, 370/516, 370/397, 370/395, 370/259, 370/396, 370/257, 370/229, 370/419, 370/232, 370/432, 370/352, 370/351, 370/389, 370/349, 370/357, 370/323, 370/355, 370/356, 370/260, 370/270, 370/390, 375/285, 709/247
• US Class Current: 370/395.2
• CPC Class Codes: H04L 2012/561 Star, e.g. cross-connect, concentrator, subscriber group equipment, remote electronics
• CPC Class Codes: H04L 2012/5615 Network termination, e.g. NT1, NT2, PBX
• CPC Class Codes: H04L 2012/5619 Network Node Interface, e.g. tandem connections, transit switching
• CPC Class Codes: H04L 2012/5638 Services, e.g. multimedia, GOS, QOS
• CPC Class Codes: H04L 2012/5651 Priority, marking, classes
• CPC Class Codes: H04L 2012/5672 Multiplexing, e.g. coding, scrambling
• CPC Class Codes: H04L 49/3081 ATM peripheral units, e.g. policing, insertion or extraction
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

The invention provides a method and apparatus for communicating to a destination node over a broadband network from plural users connected to an access node. A virtual circuit is provisioned through the broadband network for connecting the access node to the destination node. Data units are received from plural users at the access node, with each data unit having plural cells. The data units are multiplexed onto the virtual circuit at the access node such that the cells of any one data unit are noninterleaving with the cells of any other data unit on the virtual circuit. In a preferred embodiment, the destination node is a service provider node in an ATM network and the data units are Ethernet protocol data units that comprise plural ATM cells. According to another aspect, an access node for communicating to a service provider node over an ATM network includes at least one line unit for transmitting Ethernet protocol data units to and from plural users, each Ethernet protocol data unit comprising plural ATM cells, the line unit coupling the ATM cells to and from a communication bus. A trunk unit coupled to the communication bus transmits and receives ATM cells to and from the ATM network.

Claims

1. A method of communicating to first service provider nodes over an ATM network from plural users connected to an access node, the method comprising the steps of:

provisioning a first virtual circuit through the ATM network for connecting a first access node to the first service provider node;

receiving first protocol data units intended for the first service provider node from plural users at the access node, the first protocol data units comprising plural ATM cells; and

multiplexing the first protocol data units onto the first virtual circuit at the first access node such that the ATM cells of the first protocol data units are noninterleaving with the ATM cells of any other of the first protocol data units on the first virtual circuit and provisioning a second virtual circuit through the ATM network for connecting the access node to a second service provider node and wherein the step of receiving includes receiving second protocol data units intended for the second service provider node, each comprising plural ATM cells and wherein the step of multiplexing includes multiplexing the second protocol data units onto the second virtual circuit such that the ATM cells of any one of the second protocol data units are nonintcrleaving with the ATM cells of any other of the second protocol data units on the second virtual circuit.

2. The method of claim 1 wherein the first protocol data units have a first service priority and the second protocol data units have a second service priority, the first priority being higher than the second priority, and wherein the step of multiplexing includes preempting ATM cells of the second protocol data units with ATM cells of the first protocol data units.

3. The method of claim 1 further comprising transmitting from one of the plurality of users of the service provider nodes a request for a virtual circuit identifier associated with the second virtual circuit connecting the access node to a second service provider node;

transmitting the virtual circuit identifier from the service provider nodes to the one user; and

connecting the one user to the second service provider nodes using the virtual circuit identifier.

4. Apparatus for communicating to a first service provider node over an ATM network from plural users connected to an access node comprising:

a receiver for receiving first protocol data units intended for the first service provider node from plural users at the access node, each first protocol data unit comprising plural ATM cells; and

a multiplexer for multiplexing the first protocol data units onto a first virtual circuit connecting the access node to the first service provider node through the ATM network such that the ATM cells of any one Ethernet protocol data unit are noninterleaving with the ATM cells of any other Ethernet protocol data unit on the first virtual circuit and for receiving second protocol data units intended for a second service provider node, each second protocol data unit comprising plural ATM cells and means for multiplexing the second protocol data units onto a second virtual circuit connecting the access node to said second service provider node through the ATM network such that the ATM cells of any one of the second protocol data units are noninterleaving with the ATM cells of any other of the second protocol data units on the second virtual circuit.

5. The apparatus of claim 4 wherein the first protocol data units have a first service priority and the second protocol data units have a second service priority, the first priority being higher than the second priority, and wherein the means for multiplexing includes means for preempting ATM cells of the second protocol data units with ATM cells of the first protocol data units.

6. The apparatus of claim 4 wherein the first and second protocol data units comprise Ethernet protocol data units.

7. A system comprising:

plural end user sites each having a network interface device for sending and receiving protocol data units, each protocol data unit comprising plural ATM cells;

a first virtual circuit connecting an access node to a first destination node through an ATM network, the access node coupled to the plural end user sites and having means for receiving first protocol data units intended for the first destination node from the network interface devices and means for multiplexing the first protocol data units onto the first virtual circuit such that the ATM cells of any one protocol data unit are noninterleaving with the ATM cells of any other protocol data unit on the first virtual circuit and wherein the access node further comprises means for receiving second protocol data units from the end user sites and means for multiplexing the second protocol data units onto a second virtual circuit connecting the access node to a second destination node through the ATM network such that the ATM cells of any one of the second protocol data units are noninterleaving with the ATM cells of any other of the second protocol data units on the second virtual circuit.

8. The system of claim 7 wherein the first and second protocol data units comprise Ethernet protocol data units.

9. The system of claim 7 wherein the access node communicates a virtual circuit identifier to each network interface device to indicate a proper virtual circuit for communication with an associated destination node.

10. The system of claim 7 wherein each network interface device provides an ATM adaptation layer SAR function to encapsulate Ethernet frames as bridged protocol data units.

11. An access node for communicating to a service provider node over an ATM network from plural users, the access node comprising:

a communication bus for transporting ATM cells;

at least one line unit for transmitting downstream and receiving upstream protocol data units to and from plural users, each protocol data unit comprising said ATM cells, the line unit coupling the ATM cells to and from the communication bus; and

a trunk unit coupled to the communication bus for transmitting upstream ATM cells and receiving downstream ATM cells to and from the ATM network;

wherein the line unit further includes means for multiplexing the upstream protocol data units onto a virtual circuit connecting the access node to the service provider node and wherein the upstream ATM cells of any one upstream protocol data unit are noninterleaving with the upstream ATM cells of any other upstream protocol data unit on the virtual circuit and wherein the line unit further includes means for selecting downstream ATM cells from the communication bus that are destined for any of the plural users associated therewith based on a virtual circuit identifier and a PDU address in the ATM cells.

12. The access node of claim 11 wherein the upstream protocol data units comprise Ethernet protocol data units.

13. The access node of claim 11 wherein the means for selecting includes means for detecting start of a protocol data unit, means for buffering the said downstream ATM cells, means for detecting the PDU address, and means for buffering all ATM cells of the protocol data unit for transmission to a user associated with the PDU address.

14. The access node of claim 13 wherein the protocol data units comprise Ethernet protocol data units and the PDU address comprises an Ethernet MAC address.