Facility for transporting TDM streams over an asynchronous ethernet network using internet protocol

• US 6,963,561 B1
• Filed: 12/15/2000
• Issued: 11/08/2005
• Est. Priority Date: 12/15/2000
• Status: Expired due to Term

• Current Assignee: Nokia Siemens Networks Ethernet Solutions Limited (Nokia Corporation)
• Original Assignee: Atrica Israel Limited
• Inventors: Lahat, Amir
• Primary Examiner(s): Ngo, Ricky
• Assistant Examiner(s): Juntima, Nittaya
• Application Number:
  US09/738,597
• Time in Patent Office: 1,789 Days
• Field of Search: 370/401, 370/466, 370/474, 370/352, 370/465, 370/537, 370/356
• US Class Current: 370/356
• CPC Class Codes: H04J 3/0632 Synchronisation of packets and cells, e.g. transmission of voice via a packet network, circuit emulation service [CES] queuing arrangements in packet switching elements H04L49/90; synchronising systems for the synchronous transmission of a pulse code modulated video signal with one or more other pulse code modulated signals H04N7/56
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/166 IP fragmentation; TCP segmentation
• CPC Class Codes: H04L 69/168 specially adapted for link layer protocols, e.g. asynchronous transfer mode [ATM], synchronous optical network [SONET] or point-to-point protocol [PPP]
• CPC Class Codes: H04L 69/169 Special adaptations of TCP, UDP or IP for interworking of IP based networks with other networks protocols for interworking, protocol conversion H04L69/08

Abstract

A transport facility adapted to transport TDM bit streams using IP packets over an asynchronous Ethernet network. TDM bit streams such as E1, T1, E3, T3, OC-3, OC-12, STM-1, STM-4, etc. are received, buffered and encapsulated into Ethernet frames. The Circuit Emulation Device (CED) receives, buffers and assembles in real-time ingress data from TDM ports into Ethernet Frames and forwards them to an Ethernet interface. The TDM data is encapsulated within RTP, UDP and IP packets before being encapsulated within an Ethernet frame. In the egress direction, Ethernet frames enter the encapsulation/segmentation processor from the Ethernet port and the IP, UDP and RTP packets are extracted from the frame. TDM data is extracted and the bit streams are re-generated and forwarded to the TDM ports for transmission over legacy TDM facilities.

Claims

1. An apparatus for transporting a plurality of Time Division Multiplexing (TDM) streams over an asynchronous Ethernet network, comprising:

an ingress buffer for storing TDM data before encapsulation into Ethernet frames;

an egress buffer for storing TDM data after received Ethernet frames are segmented;

encapsulation means for retrieving TDM data from said ingress buffer, assembling Ethernet frames therefrom, inserting therein a first timestamp related to said TDM data and forwarding said assembled Ethernet frames to an Ethernet interface;

segmentation means for receiving Ethernet frames from said Ethernet interface, extracting TDM data and a second timestamp therefrom and storing said TDM data in said egress buffer; and

a processor comprising means for;

receiving TDM data from a plurality of TDM ports;

storing received TDM data in a queue within said ingress buffer wherein all TDM data to be encapsulated within an Ethernet frame is stored together; and

retrieving TDM data from said egress buffer and generating a plurality of synchronous TDM data streams therefrom.

2. The apparatus according to claim 1, wherein said plurality of TDM streams comprises streams selected from a group comprising E1, T1, E3, T3, OC-3, STM-1, OC-12, and STM-4 streams.

3. The apparatus according to claim 1, wherein said encapsulation means encapsulates data from said plurality of TDM ports into a single Ethernet frame.

4. The apparatus according to claim 1, wherein said encapsulation means encapsulates data from a plurality of TDM frames corresponding to a single TDM port into a single Ethernet frame.

5. The apparatus according to claim 1, wherein said segmentation means segments an Ethernet frame into a plurality of TDM streams, each TDM stream corresponding to a different TDM port.

6. The apparatus according to claim 1, wherein said segmentation means segments an Ethernet frame into a plurality of TDM frames corresponding to a single TDM port.

7. The apparatus according to claim 1, wherein said processor for storing TDM data received from a plurality of TDM ports in accordance with specific port based parameters.

8. The apparatus according to claim 1, wherein said processor for storing TDM data received from a plurality of TDM ports in accordance with specific time based parameters.

9. The apparatus according to claim 1, wherein said encapsulation means receives TDM data on a plurality of constant synchronous serial bit streams.

10. The apparatus according to claim 1, wherein said encapsulation means encrypts said TDM data before packaging said TDM data into Ethernet frames.

11. The apparatus according to claim 1, wherein said encapsulation means compresses said TDM data before packaging said TDM data into Ethernet frames.

12. The apparatus according to claim 1, wherein said encapsulation means calculates a Cyclic Redundancy Check (CRC) code for use in packaging said TDM data into Ethernet frames.

13. The apparatus according to claim 1, wherein said encapsulation means comprises:

means for packaging TDM stream data into Real Time Protocol (RTP) packets, then into User Datagram Protocol (UDP) packets, then into Internet Protocol (IP) packets and finally into Ethernet frames; and

means for generating appropriate header information for said RTP packets, UDP packets, IP packets and Ethernet frames or a subset thereof.

14. The apparatus according to claim 1, wherein said encapsulation means forwards Ethernet frames toward an Ethernet Media Access Control (MAC) device.

15. The apparatus according to claim 1, wherein said segmentation means comprises;

means for extracting TDM stream data from the contents of a Real Time Protocol (RTP) packet, User Datagram Protocol (UDP) packet and Internet Protocol (IP) packet extracted from a received Ethernet frame; and

means for storing said TDM data in said egress buffer in accordance with the contents of RTP header information.

16. The apparatus according to claim 1, wherein said processor for performing rate adaptation between a plurality of TDM ports and an egress buffer interface.

17. The apparatus according to claim 1, wherein said processor for forwarding TDM frames to appropriate TDM ports as a constant synchronous serial or parallel bit stream.

18. An apparatus for transporting TDM streams over an Ethernet network, comprising;

a plurality of TDM port interfaces coupled to a plurality of TDM ports, each TDM port for receiving a constant synchronous serial or parallel TDM stream;

at least one Ethernet interface coupled to said Ethernet network;

encapsulation means for retrieving TDM data from an ingress buffer, assembling Ethernet frames therefrom, inserting therein a first timestamp related to said TDM data and forwarding said assembled Ethernet frames to said Ethernet interface;

segmentation means for receiving Ethernet frames from said Ethernet interface, extracting TDM data and a second timestamp therefrom and storing said TDM data in an egress buffer; and

a processor comprising means for;

receiving TDM data from a plurality of TDM ports;

storing received TDM data in a queue within said ingress buffer wherein all TDM data to be assembled within a single Ethernet frame is stored together; and

retrieving TDM data from said egress buffer and generating a plurality of TDM data streams therefrom.

19. The apparatus according to claim 18, wherein said Ethernet interface comprises a 10Base-T Ethernet interface.

20. The apparatus according to claim 18, wherein said Ethernet interface comprises a 100Base-T Fast Ethernet interface.

21. The apparatus according to claim 18, wherein said Ethernet interface comprises a 1000Base-T Gigabit Ethernet interface.

22. The apparatus according to claim 18, wherein said Ethernet interface comprises a 10 Gigabit Ethernet interface.

23. The apparatus according to claim 18, wherein said plurality of TDM port interfaces comprises at least one port interface selected from a group comprising E1, T1, E3, T3, OC-3, STM-1, OC-12 and STM-4 port interfaces.

24. The apparatus according to claim 18, wherein said encapsulation means encapsulates data from said plurality of TDM ports into a single Ethernet frame.

25. The apparatus according to claim 18, wherein said encapsulation means encapsulates data from a plurality of TDM frames corresponding to a single TDM port into a single Ethernet frame.

26. The apparatus according to claim 18, wherein said segmentation means segments an Ethernet frame into a plurality of TDM streams, each TDM stream corresponding to a different TDM port.

27. The apparatus according to claim 18, wherein said segmentation means segments an Ethernet frame into a plurality of TDM frames corresponding to a single TDM port.

28. The apparatus according to claim 18, wherein said processor for storing TDM data received from a plurality of TDM ports in accordance with specific port based parameters.

29. The apparatus according to claim 18, wherein said processor for storing TDM data received from a plurality of TDM ports in accordance with specific lime based parameters.

30. The apparatus according to claim 18, wherein said encapsulation means comprises:

means for packaging TDM stream data into Real Time Protocol (RTP) packets, then into User Datagram Protocol (UDP) packets, then into Internet Protocol (IP) packets and finally into Ethernet frames; and

means for generating appropriate header information for said RTP packets, UDP packets, IP packets and Ethernet frames or any subset thereof.

31. The apparatus according to claim 18, wherein said segmentation means comprises:

means for extracting TDM stream data from the contents of a Real Time Protocol (RTP) packet, User Datagram Protocol (UDP) packet and Internet Protocol (IP) packet extracted from a received Ethernet frame; and

means for storing said TDM data in said egress buffer in accordance with the contents of RTP header information or any subset thereof.

32. A method of transporting a plurality of Time Division Multiplexing (TDM) streams over an Ethernet network, said method comprising the steps of:

receiving TDM stream data from a plurality of TDM ports;

storing received TDM stream data in a queue within an ingress buffer wherein all TDM data to be assembled into a single Ethernet frame is stored together;

assembling Ethernet frames from received TDM stream data retrieved from said queue and inserting therein a first timestamp related to said IM stream data;

forwarding said assembled Ethernet frames to said Ethernet network via an Ethernet interface connected thereto;

receiving Ethernet frames from said Ethernet network;

extracting TDM data and a second timestamp from said received Ethernet frames and generating TDM streams therefrom; and

forwarding said generated TDM streams to an appropriate TDM port in a synchronous manner.

33. The method according to claim 32, wherein said step of receiving TOM stream data comprises the step of storing said TDM data in an ingress buffer in accordance with an output Ethernet frame to be generated.

34. The method according to claim 32, wherein said step of extracting comprises the step of storing segmented TDM data in an egress buffer.

35. The method according to claim 32, wherein said Ethernet interface comprises a 10Base-T Ethernet interface.

36. The method according to claim 32, wherein said Ethernet interface comprises a 100Base-T Fast Ethernet interface.

37. The method according to claim 32, wherein said Ethernet interface comprises a 100Base-T Gigabit Ethernet interface.

38. The method according to claim 32, wherein said Ethernet interface comprises a 10 Gigabit Ethernet interface.

39. The method according to claim 32, wherein said plurality of TDM port interfaces comprises at least one port interface selected from a group comprising E1, T1, E3, T3, OC-3, STM-1, OC-12 AND STM-4 port interfaces.

40. The method according to claim 32, wherein said step of assembling comprises the step of encapsulating data from said plurality of TDM ports into a single Ethernet frame.

41. The method according to claim 32, wherein said step of assembling comprises the step of encapsulating data from a plurality of TDM frames corresponding to a single TDM port into a single Ethernet frame.

42. The method according to claim 32, wherein said step of extracting comprises the step of segmenting an Ethernet frame into a plurality of TDM streams, each TDM stream corresponding to a different TDM port.

43. The method according to claim 32, wherein said step of extracting comprises the step of segmenting an Ethernet frame into a plurality of TDM frames corresponding to a single TDM port.

44. The method according to claim 32, further comprising the step of storing TDM data received from a plurality of TDM ports in accordance with specific port based parameters.

45. The method according to claim 32, further comprising the step of storing TDM data received from a plurality of TDM ports in accordance with specific time based parameters.

46. The method according to claim 32, wherein said step of assembling comprises the steps of:

packaging TDM stream data into Real Time Protocol (RTP) packets, then into User Datagram Protocol (UDP) packets, then into Internet Protocol (IP) packets and finally into Ethernet frames; and

generating appropriate header information for said RTP packets, UDP packets, IP packets and Ethernet frames or a subset thereof.

47. The method according to claim 32, wherein said step of extracting comprises the steps of:

extracting TDM stream data from the contents of a Real Time Protocol (RTP) packet, User Datagram Protocol (UDP) packet and Internet Protocol (IP) packet extracted from a received Ethernet frame; and

storing said TDM data in said egress buffer in accordance with the contents of RTP header information.