Method and apparatus for automatically detecting virtual circuit settings and encapsulation types in a DSL network

• US 7,489,693 B2
• Filed: 09/18/2002
• Issued: 02/10/2009
• Est. Priority Date: 09/18/2002
• Status: Expired due to Fees

• Current Assignee: Ikanos Communications Incorporated (Qualcomm, Inc.)
• Original Assignee: Conexant Systems Incorporated (Synaptics Incorporated)
• Inventors: Xu, Haibo
• Primary Examiner(s): Pham; Chi H
• Assistant Examiner(s): Jain; Raj K
• Application Number:
  US10/245,982
• Publication Number:
  US 20040052263A1
• Time in Patent Office: 2,337 Days
• Field of Search: None
• US Class Current: 370/395.5
• 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 12/2859 Point-to-point connection between the data network and the subscribers encapsulation H04L12/4633; virtual LANs H04L12/4641; routing of packets H04L45/00
• CPC Class Codes: H04L 12/2889 Multiservice, e.g. MSAN
• CPC Class Codes: H04L 12/5601 Transfer mode dependent, e.g. ATM
• CPC Class Codes: H04L 2012/5615 Network termination, e.g. NT1, NT2, PBX
• CPC Class Codes: H04L 2012/5617 Virtual LANs; Emulation of LANs
• CPC Class Codes: H04L 2012/5625 Operations, administration and maintenance [OAM]
• CPC Class Codes: H04L 2012/5672 Multiplexing, e.g. coding, scrambling
• 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 69/168 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 69/24 Negotiation of communication capabilities
• CPC Class Codes: H04M 11/062 using different frequency bands for speech and other data

Abstract

Automatic detection of the virtual circuit setting and encapsulation type of a DSL line. A DSL modem determines the correct virtual path identifier (VPI) and virtual channel identifier (VCI) by sending OAM loopback requests to different VPI/VCI pairs until a valid loopback reply is received. PPPoA encapsulation is detected when a valid reply is received to a PPP LCP configuration request or echo request. PPPoE encapsulation is detected when a valid reply is received to a PPP LCP termination request or a PPPoE discovery offer (a PADO packet) is received in response to a PPPoE discovery initiation request (a PADI packet).

Claims

1. A method for determining whether a DSL line (digital subscriber line) is using PPPoA (point-to-point protocol over asynchronous transfer mode) encapsulation comprising:

sending a PPP/LCP (point-to-point protocol/link control protocol) configure-request packet;

if a reply to the sent configure-request packet is received, storing the encapsulation type as PPPoA;

sending a PPP/LCP echo-request packet; and

if a reply to the sent echo-request packet is received, storing the encapsulation type as PPPoA,

wherein the PPP/LCP configure-request and echo-request packets are sent simultaneously.

2. A method as claimed in claim 1, wherein the reply to the configure-request packet is a PPP/LCP configure-ack packet, configure-nak packet or configure-reject packet.

3. A method as claimed in claim 1, wherein the reply to the echo-request packet is a PPP/LCP echo-reply packet.

4. A method as claimed in claim 1, wherein configure-request and echo-request packets are sent rapidly and alternately for a pre-determined time period or until a reply to either a configure-request packet or echo-request packet is received.

5. A method as claimed in claim 1, wherein the method is carried out by software residing in a DSL modem.

6. A method as claimed in claim 1, wherein if any reply to the sent configure-request packet is received, determining the encapsulation type as PPPoA.