Proxy MPC for providing MPOA services to legacy lane clients in an asynchronous transfer mode network

• US 6,614,792 B1
• Filed: 05/27/1999
• Issued: 09/02/2003
• Est. Priority Date: 05/27/1999
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Pazy, Offer, Yaron, Opher
• Primary Examiner(s): Ngo, Ricky
• Assistant Examiner(s): Lee, Timothy
• Application Number:
  US09/322,063
• Time in Patent Office: 1,559 Days
• Field of Search: 370/395.5, 370/395.51, 370/395.53, 370/395.54, 370/395.2, 370/249, 370/395.1, 370/396, 370/397, 370/400, 370/401, 370/409, 370/466, 370/465
• US Class Current: 370/395.53
• CPC Class Codes: H04L 12/5601 Transfer mode dependent, e.g. ATM
• CPC Class Codes: H04L 2012/5617 Virtual LANs; Emulation of LANs
• CPC Class Codes: H04L 2012/5669 Multiprotocol over ATM [MPOA]
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols

Abstract

A proxy MPOA client in a VLAN that is otherwise populated by legacy LECs such that the MPOA services for these LECs are provided centrally by the proxy MPC. A standard MPC enabled edge device is adapted to provide MPC services to legacy LECs that are not MPOA aware. Such an edge device provides MPOA services to legacy LECs located in other edge devices connected to the ATM cloud. The proxy MPC is configured to have at least two LECs: one residing on a legacy ELAN and another residing on an MPOA ELAN. Traffic from the legacy LEC arriving from the legacy ELAN is forwarded to an Ethernet port that is looped back to a second Ethernet port on the proxy MPC edge device. Upon ingress at the second Ethernet port, the traffic is treated as if it arrived from a regular port and provided with MPC services. The loopback may be implemented either internally or externally via one or more cables. In addition, an internal bridge is configured to steer the Ethernet traffic to the first Ethernet port for loopback to the second Ethernet port. Upon initial flow detection, the proxy MPC establishes a shortcut utilizing the MPOA Server (MPS). Once the shortcut is established, traffic is forwarded from the LEC on the MPOA side in the proxy MPC to the destination via the shortcut.

Claims

1. A proxy Multiprotocol Over ATM (MPOA) Client (MPC) for use in an ATM network including one or more legacy LAN Emulation Clients (LECs) that are not MPOA aware and at least one MPOA Server (MPS), comprising:

a first port adapted to communicate data over a first Emulated LAN (ELAN) comprising a legacy ELAN;

a second port adapted to communicate data over a second ELAN comprising an MPOA ELAN, said MPOA ELAN comprising an MPS, wherein said first port and said port are colocated within the same device;

a first LEC adapted to reside on said first ELAN, said legacy LEC also residing on said first ELAN;

a second LEC adapted to reside on said second ELAN, said MPS also residing on said second ELAN;

a loopback connection adapted to loopback said first port and said second port such that traffic ingressed to said second port is treated as regular frames and provided MPC services; and

a bridge adapted to steer traffic ingressing from said first ELAN via said first LEC over said loopback to egress to said second ELAN via said second LEC, said bridge adapted to steer traffic ingressing from said second ELAN via said second LEC over said loopback to egress to said first ELAN via said first LEC.

2. The proxy MPC according to claim 1, wherein said loopback connection comprises one or more internal loopback connections.

3. The proxy MPC according to claim 1, wherein said loopback connection comprises one or more external loopback connections.

4. The proxy MPC according to claim 1, wherein said bridge comprises:

a first Forwarding Database (FDB) adapted to store mappings between said first ELAN and said first port for both ingress and egress directions; and

a second Forwarding Database (FDB) adapted to store mappings between said second ELAN and said second port for both ingress and egress directions.

5. The proxy MPC according to claim 1, wherein said legacy LEC and said first LEC communicate via a LAN Emulation (LANE) Data Direct Virtual Circuit (DDVC).

6. The proxy MPC according to claim 1, wherein said second LEC and said MPS communicate via a LAN Emulation (LANE) Data Direct Virtual Circuit (DDVC).

7. The proxy MPC according to claim 1, wherein said second LEC is operative to forward traffic to said MPS using LANE mechanisms before an MPOA shortcut is established.

8. The proxy MPC according to claim 1, wherein said second LEC is operative to forward traffic to an MPOA shortcut once said MPOA shortcut is established.

9. The proxy MPC according to claim 1, wherein said first port comprises an Ethernet port adapted to transmit/receive Ethernet data to/from said first ELAN.

10. The proxy MPC according to claim 1, wherein said second port comprises an Ethernet port adapted to transmit/receive Ethernet data to/from said second ELAN.

11. The proxy MPC according to claim 1, wherein said first port comprises a Token Ring port adapted to transmit/receive Token Ring data to/from said first ELAN.

12. The proxy MPC according to claim 1, wherein said second port comprises a Token Ring port adapted to transmit/receive Token Ring data to/from said second ELAN.

13. The proxy MPC according to claim 1, wherein said first port comprises a port adapted to transmit/receive Layer 2 protocol data to/from said first ELAN.

14. The proxy MPC according to claim 1, wherein said second port comprises a port adapted to transmit/receive Layer 2 protocol data to/from said second ELAN.

15. A method of providing proxy Multiprotocol Over ATM (MPOA) Client (MPC) services to one or more legacy LAN Emulation Clients (LECs) that are not MPOA aware, in an Asynchronous Transfer Mode (ATM) network including at least one MPOA Server (MPS), said method comprising the steps of:

forwarding frames from a legacy LEC to a first LEC, said first LEC and said legacy LEC residing on a first ELAN comprising a legacy ELAN;

forwarding frames arriving to said first LEC to a first port;

providing a second port adapted to communicate data over a second ELAN comprising an MPOA ELAN, said MPOA ELAN comprising an MPS, wherein said first port and said port are colocated within the same device;

configuring a bridge so as to forward traffic arriving from said legacy LEC to said first port and to forward traffic ingressed to said second port to said MPS; and

looping traffic arriving to said first port back to a second port thus causing traffic ingressed to said second port to be provided MPC services.

16. The method according to claim 15, further comprising the step of forwarding traffic to said MPS before an MPOA shortcut is established upon detecting initial traffic flow.

17. The method according to claim 15, further comprising the step of forwarding traffic to an MPOA shortcut once said MPOA shortcut is established.

18. The method according to claim 15, further comprising the step of communicating frames from said legacy LEC to said first LEC via a LAN Emulation (LANE) Data Direct Virtual Circuit (DDVC).

19. The method according to claim 15, further comprising the step of forwarding frames from a second LEC associated with the second port to said MPS via a LAN Emulation (LANE) Data Direct Virtual Circuit (DDVC).

20. The method according to claim 15, wherein said first port comprises an Ethernet port adapted to transmit/receive Ethernet data to/from said first ELAN.

21. The method according to claim 15, wherein said second port comprises an Ethernet port adapted to transmit/receive Ethernet data to/from said second ELAN.

22. The method according to claim 15, wherein said first port comprises a Token Ring port adapted to transmit/receive Token Ring data to/from said first ELAN.

23. The method according to claim 15, wherein said second port comprises a Token Ring port adapted to transmit/receive Token Ring data to/from said second ELAN.

24. The proxy MPC according to claim 15, wherein said first port comprises a port adapted to transmit/receive Layer 2 protocol data to/from said first ELAN.

25. The proxy MPC according to claim 15, wherein said second port comprises a port adapted to transmit/receive Layer 2 protocol data to/from said second ELAN.