Method and apparatus for converting data packets between a higher bandwidth network and a lower bandwidth network having multiple channels

• US 7,386,008 B2
• Filed: 05/07/2002
• Issued: 06/10/2008
• Est. Priority Date: 07/19/2001
• Status: Active Grant

• Current Assignee: Reuvem D. Jordan
• Original Assignee: ECI Telecom Limited (Shaul Shani)
• Inventors: Jordan, Reuven D.
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): ZHU, BO HUI ALVIN
• Application Number:
  US10/139,398
• Publication Number:
  US 20030016697A1
• Time in Patent Office: 2,226 Days
• Field of Search: 370/466, 370/467
• US Class Current: 370/466
• CPC Class Codes: H04J 2203/0085 Support of Ethernet
• CPC Class Codes: H04J 3/1617 carrying packets or ATM cells
• CPC Class Codes: H04L 2007/045 Fill bit or bits, idle words
• CPC Class Codes: Y10S 370/907 Synchronous optical network, SONET

Abstract

A method and apparatus for converting packetized data received from a broadband network to a multi-channel payload network having a narrower bandwidth is disclosed. The method includes converting a packet received from the broadband network to a serial stream having first and second pluralities of bytes, the second plurality of bytes being idle; removing the idle bytes from the serial stream thereby providing a reduced data; demultiplexing sequentially occurring reduced data across plural channels of a narrower bandwidth payload network and converting each channels reduced data to corresponding second packets of the payload network. The method also includes receiving the respective second packets from the respective channels of the payload network; converting the packets to corresponding serial data streams and multiplexing the streams to restore an original sequence; inserting substitute idle bytes in substitution of the idle bytes removed from the first serial stream thereby providing a restored data; and converting the multiplexed and restored data to a third packet of the broadband network.

Claims

1. A method for converting a data stream comprising first data having a plurality of first data packets and idle bytes interposed therebetween received from a broadband network to another data stream, comprising second data having the plurality of second data packets for communication on a payload network having a narrower bandwidth than said broadband network, said payload network having two channels, method comprising

receiving the first data from the broadband network;

converting said first data into a serial data-stream;

identifying idle bytes and non-idle bytes in said serial data-stream;

removing said idle bytes from said first data thereby providing a reduced data;

providing said reduced data to one or another of said two channels of said payload network as follows;

writing said non-idle bytes into a first buffer if space is available therein;

writing said non-idle bytes into a second buffer if space is not available in said first buffer;

writing a place keeping flag into said first and second buffers in substitution of an idle byte omitted from the data stream stored therein;

outputting said non-idle bytes from each of said first and second buffers; and

converting said outputted non-idle bytes into respective said second data packets.

2. The method as claimed in claim 1 wherein said broadband network is a 1 Gb Ethernet network.

3. The method as claimed in claim 1 wherein said payload network is a SONET network.

4. The method as claimed in claim 3 wherein said SONET network is selected from the group consisting of (OC 1, OC3, and OC12).

5. The method as claimed in claim 1 wherein said first data packet is formatted in accordance with a protocol of said broadband network.

6. The method of claim 1 further comprising using a GFP or POS protocol.

7. The method of claim 1 further comprising outputting said place keeping flag from said buffer.

8. The method of claim 1 further comprising writing a switch flag into said first and second buffers whenever a first of two successive serial data streams is written into one of said two channels and a second of two successive data streams is written into another of said two channels.

9. The method as claimed in claim 1 wherein said step of identifying said idle bytes and said non-idle bytes is in response to a first clock signal, said first clock signal corresponding to a timing of said first data packets.

10. The method as claimed in claim 1 wherein said step of writing said non-idle bytes into said buffer is in response to a first clock signal, said first clock signal corresponding to a timing of said first data packets.

11. The method as claimed in claim 1 wherein said step of converting said outputted non-idle bytes to said second data packets is in response to a payload network clock signal.

12. The method as claimed in claim 1 further comprising deserializing said non-idle bytes outputted from said buffers.

13. The method as claimed in claim 1 further comprising formatting said second data packet in accordance with a protocol of said payload network.

14. A method for converting a first data packet and a second data packet from a format of a first broadband network to a format of a payload network for transmission thereon and thereafter converting back to a format of the first broadband network, comprising

converting bytes of said first data packet to a first serial data stream;

identifying idle bytes and non-idle bytes in said first serial data stream;

sequentially writing said non-idle bytes of said first data stream into one of two buffers;

inserting a place keeping flag into said one of two buffers at a location corresponding to a location of an idle byte next following said non-idle byte;

converting bytes of said second data packet to a second serial data stream;

identifying idle bytes and non-idle bytes in said second serial data stream;

sequentially writing said non-idle bytes of said second serial data stream into another of two buffers;

inserting a place keeping flag into said another of two buffers at a location corresponding to a location of an idle byte next following said icon-idle byte;

inserting a switch flag into said one of two buffers;

serially outputting a contents of each of said two buffers;

converting said outputted contents to respective payload network packets;

converting said payload network packets to respective payload network serial data streams;

writing said payload network serial data streams to respective buffers;

identifying said place keeping flags in each of said payload network serial data streams;

replacing said place keeping flags with substitute idle bytes, thereby obtaining and resequencing said respective first and second serial data streams in relation to each other.

15. A communication system for converting data packets of a broadband network, comprising non-idle bytes and idle bytes together forming first data into data packets of a narrower bandwidth payload network, comprising non-idle bytes, the system comprising:

a receiver for receiving said first data;

an idle bytes identifier in communication with said receiver;

a demultiplexer connected to said idle bytes identifier;

two buffers connected to said demultiplexer;

a logic circuit connected to said idle bytes identifier and said two buffers for enabling and disabling writing of said first data into one or another of said two buffers, in response to a signal from said idle bytes identifier; and

means for inserting a place keeping flag in one or another of said two buffers in substitution of said idle bytes when said logic circuit disables writing of said first data.

16. The communication system as claimed in claim 15 wherein said broadband network is a 1 Gb Ethernet network.

17. The communication system as claimed in claim 15 wherein said narrower bandwidth payload network is a SONET network.

18. The communications system as claimed in claim 17 wherein said SONET network is selected from the group consisting of OC1, OC3 and OC12.

19. The communications system as claimed in claim 15 further comprising a first converter for converting a data packet in a format of said broadband network to said first data.

20. The communications system as claimed in claim 15 wherein each of said two buffers further comprises

a read pointer and a write pointer;

wherein said logic circuit is further controlled by said read pointer and said write pointer.

21. The communications system as claimed in claim 15 adapted for writing said first data into any of said two buffers at a rate corresponding to a clock rate of said broadband network.

22. The communications system as claimed in claim 15 adapted mr reading said non-idle bytes and said place keeping flags from any of said two buffers at a rate corresponding to a clock rate of said payload network.

23. The communications system as claimed in claim 15 further comprising a second converter for converting said non-idle bytes and said place keeping flags from any of said two buffers to a data packet in a format for said payload network.

24. A communication system for converting data packets from a format of a payload network to a format of a broadband network having a wider bandwidth than said payload network, comprising

two channels for respectively carrying first and second data each of said first and second data having non-idle bytes and place keeping flags;

first and second buffers for buffering said first and second data, respectively;

a multiplexer connected to said first and second buffers;

means for replacing said place keeping flags by substitute idle bytes,

and a logic circuit for switching an input of said multiplexer from a first of said two buffers to another of said two buffers in response to a switch flag appended to one of said first and second data.

25. The communication system as claimed in claim 24 wherein said broadband network is a 1 Gb Ethernet network.

26. The communication system as claimed in claim 24 wherein said payload network is a SONET network.

27. The communication system as claimed in claim 26 wherein said SONET network is selected from the group consisting of OC1, OC3, and OC12.

28. The communications system as claimed in claim 24, further comprising a first converter for converting a data packet in a format of said payload network to said first data.

29. The communications system as claimed in claim 24, further comprising a second converter for converting an output of Said buffer to a data packet in a format of said broadband network.

30. The communications system as claimed in claim 24, adapted for writing said first and second data into said first and second buffers at a rate corresponding to a clock rate of said payload network.

31. The communications system as claimed in claim 24, adapted for output from said first and second buffers said first and second data at a rate corresponding to a clock rate of said broadband network.