System for transporting ethernet frames over very high speed digital subscriber lines

• US 6,680,940 B1
• Filed: 05/19/1999
• Issued: 01/20/2004
• Est. Priority Date: 05/19/1999
• Status: Expired due to Term

• Current Assignee: Far North Patents, LLC
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Poddobny, Yuri, Sfadya, Yackov, Mann, Eytan, Lewin, Amit
• Primary Examiner(s): Olms, Douglas
• Assistant Examiner(s): Nguyen, Van Kim T.
• Application Number:
  US09/315,215
• Time in Patent Office: 1,707 Days
• Field of Search: 370/389, 370/352-358, 370/397, 370/419, 370/440, 370/465, 370/466, 370/467, 370/469, 370/492, 370/493-494, 370/522
• US Class Current: 370/389
• CPC Class Codes: H04L 12/2856 Access arrangements, e.g. Internet access asynchronous transfer mode networks H04L12/5601; broadband local area networks H04L12/2801; optical access or distribution networks H04Q11/0067; access to open networks H04L12/5691; digital subscriber line end-user equipment and bit-level processing of data on a PSTN-based network H04M11/00; home network gateways H04L12/2834; wireless access networks H04W
• CPC Class Codes: H04L 12/2881 IP/Ethernet DSLAM
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 2212/00 Encapsulation of packets
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04M 11/062 using different frequency bands for speech and other data
• CPC Class Codes: H04M 3/007 Access interface units for simultaneous transmission of speech and data, e.g. digital subscriber line [DSL] access interface units DSL access multiplexers H04Q11/0478, and H04L12/2856

Abstract

An apparatus for and method of encapsulating Ethernet frames over a Very high speed Digital Subscriber Line (VDSL) transport facility. The VDSL frames are transmitted over a point to point VDSL link where they are subsequently extracted and forwarded as standard Ethernet frames. The VDSL facility transport system comprises an Ethernet to VDSL Customer Premises Equipment (CPE) coupled to a DSL Access Multiplexor (DSLAM) over a VDSL transport facility. The Ethernet to VDSL CPE functions to receive a 10 BaseT Ethernet signal and encapsulate the Ethernet frame into a VDSL frame for transmission over the VDSL facility. The DSLAM is adapted to receive VDSL frames, extract Ethernet frames therefrom and generate and output a standard Ethernet signal. Ethernet frames are encapsulated within VDSL frames and transmitted on the wire pair without regard to the state of the Tx and Rx SOC signals output by the VDSL transceiver.

Claims

1. An apparatus for encapsulating and extracting Ethernet frames to and from a Very high speed Digital Subscriber Line (VDSL) facility, comprising:

an Ethernet transceiver for receiving and transmitting Ethernet frames from and to an Ethernet source;

a VDSL transceiver for receiving and transmitting VDSL frames from and to said VDSL facility; and

an Ethernet encapsulation/extraction (EEE) unit coupled to said Ethernet transceiver and said VDSL transceiver, the EEE unit operative to;

store Ethernet frames received from said Ethernet source by said Ethernet transceiver;

encapsulate within VDSL frames Ethernet frames received from said Ethernet source for transmission over said DSL facility by said VDSL transceiver;

extract Ethernet frames received from said VDSL facility by said VDSL transceiver; and

store said Ethernet frames received from said VDSL facility for transmission to said Ethernet transceiver.

2. The apparatus according to claim 1, wherein said Ethernet encapsulation/extraction unit comprises:

Ethernet input circuitry coupled to the receive portion of said Ethernet source and operative to convert the Tx serial input bitstream to a parallel stream of Tx bytes;

Ethernet output circuitry coupled to the receive portion of said Ethernet source and operative to convert a parallel stream of Rx bytes into a Rx serial bitstream;

VDSL output circuitry coupled to the transmit portion of said VDSL facility and operative to transfer VDSL frames ready for transmission to said VDSL transceiver;

VDSL input circuitry coupled to the receive portion of said of said VDSL facility and operative to receive VDSL frames from said VDSL transceiver;

a memory unit for storing data received from said Ethernet input circuitry and said VDSL input circuitry; and

a data processor coupled to said Ethernet input circuitry, Ethernet output circuitry, said VDSL output circuitry and said VDSL input circuitry, said data processor operative to store and forward data received via said Ethernet input circuitry to said VDSL output circuitry, said data processor operative to store and forward data received via said VDSL input circuitry to said Ethernet output circuitry.

3. The apparatus according to claim 1, wherein said Ethernet transceiver comprises a 10BaseT Ethernet transceiver operative to communicate with a 10BaseT Ethernet source.

8. The apparatus according to claim 1, wherein VDSL frames are transmitted over Said VDSL facility without regard to Rx and Tx Start of Cell (SOC) signals provided by said VDSL transceiver.

9. The apparatus according to claim 1, wherein a preamble is utilized to detect the start of VDSL frames.

10. The apparatus according to claim 1, wherein a length field transmitted in said VDSL frames is utilized in determining the end of VDSL frames.

11. The apparatus according to claim 1, wherein said EEE unit comprises means for re-synchronizing after an error is detected in a received VDSL fame.

12. The apparatus according to claim 1, wherein said EEE unit comprises means for performing rate matching between VDSL and Ethernet streams utilizing a backpressure signal output to said Ethernet transceiver.

13. The apparatus according to claim 1, said EEE unit comprises means for transmitting zero bytes when said Ethernet source is in an idle state, said transmission of zero bytes enabling a receiver to detect a start of Ethernet frame.

20. The method according to claim 1, wherein VDSL frames are transmitted over said VDSL facility without regard to Rx and Tx Start of Cell (SOC) signals provided by said VDSL transceiver.

21. The method according to claim 1, further comprising the step of transmitting zero bytes when said Ethernet source is in an idle state, said transmission of zero bytes enabling a receiver to detect a start of Ethernet frame.

22. The method according to claim 1, further comprising the step of performing rate matching between VDSL and Ethernet steams utilizing a backpressure signal output to an Ethernet transceiver.

4. A Digital Subscriber Line Access Multiplexor (DSLAM) for encapsulating and extracting Ethernet frames to and from one or more Very high speed Digital Subscriber Line (VDSL) facilities, comprising:

a plurality of VDSL transceivers for receiving and transmitting VDSL frames tom and to said VDSL facilities;

an Ethernet transceiver for receiving and transmitting Ethernet frames from and to an Ethernet source;

an Ethernet encapsulation/extraction (EEE) unit coupled to said plurality of VDSL transceivers and operative to;

extract Ethernet frames from said VDSL frames received from said VDSL facility;

store said Ethernet frames for transmission to said Ethernet transceiver;

store Ethernet frames received from said Ethernet source for subsequent encapsulation within VDSL frames for transmission over said VDSL facilities; and

an Ethernet switch operative to provide switching functions for one or more bidirectional Ethernet frame streams to and from of said EEE and said Ethernet transceiver.

5. The apparatus according to claim 4, wherein said Ethernet encapsulation/extraction unit comprises:

Ethernet input circuitry coupled to the transmit portion of said Ethernet source and operative to convert a plurality of Tx serial input bitstreams to a plurality of parallel streams of Tx bytes;

Ethernet output circuitry coupled to the receive portion of said Ethernet source and operative to convert a plurality of parallel streams of Rx bytes into a plurality of Rx serial bitstreams;

VDSL output circuitry coupled to the transmit portion of each VDSL facility and operative to transfer VDSL frames ready for transmission to said VDSL transceivers;

VDSL input circuitry coupled to the receive portion of each VDSL facility and operative to receive VDSL frames from said VDSL transceivers;

a memory unit for storing data received from said Ethernet input circuitry and said VDSL input circuitry; and

a data processor coupled to said Ethernet input circuitry, Ethernet output circuitry, said VDSL output circuitry and said VDSL input circuitry said data processor operative to store and forward data received via said Ethernet input circuitry to said VDSL output circuitry, said data processor operative to store and forward data received via said VDSL input circuitry to said Ethernet output circuitry.

6. The apparatus according to claim 4, wherein said Ethernet transceiver comprises a 100BaseT Ethernet transceiver operative to communicate with a 100BaseT Ethernet source.

7. The apparatus according to claim 4, wherein said Ethernet switch comprises an Ethernet switch adapted to switch between a plurality of 10BaseT Ethernet channels and at least one 100BaseT Ethernet source.

14. The DSLAM according to claim 4, wherein VDSL frames are transmitted over said VDSL facility without regard to Rx and Tx Start of Cell (SOC) signals provided by said VDSL transceiver.

15. The DSLAM according to claim 4, wherein a preamble is utilized to detect the start of VDSL frames.

16. The DSLAM according to claim 4, wherein a length field transmitted in said VDSL frames is utilized in determining the end of VDSL frames.

17. The DSLAM according to claim 4, wherein said EEE unit comprises means for re-synchronizing after an error is detected in a received VDSL frame.

18. The DSLAM according to claim 4, wherein said EEE unit comprises means for performing rate matching between VDSL and Ethernet streams utilizing a backpressure signal output to said Ethernet transceiver.

19. The DSLAM according to claim 4, said EEE unit comprises means for transmitting zero bytes when said Ethernet source is in an idle state, said transmission of zero bytes enabling a receiver to detect a start of Ethernet frame.

23. The method according to claim 14, wherein a preamble is utilized to detect the start of VDSL frames.

24. The method according to claim 14, wherein a length field transmitted in said VDSL frames is utilized in determining the end of VDSL frames.

25. The method according to claim 14, wherein said step of receiving comprises the step of re-synchronizing after an error is detected in a received VDSL frame.