Techniques for migrating a point to point protocol to a protocol for an access network

• US 8,086,749 B2
• Filed: 12/16/2008
• Issued: 12/27/2011
• Est. Priority Date: 11/29/2004
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Townsley, William Mark, Jones, Huw, Mammoliti, Vincent John
• Primary Examiner(s): Jaroenchonwanit, Bunjob
• Application Number:
  US12/335,841
• Publication Number:
  US 20090154466A1
• Time in Patent Office: 1,106 Days
• Field of Search: None
• US Class Current: 709/230
• CPC Class Codes: H04L 69/03 Protocol definition or specification protocol conformance testing H04L1/244
• 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 69/324 in the data link layer [OSI layer 2], e.g. HDLC

Abstract

Techniques for managing a persistent session associated with a particular Media Access Control (MAC) include determining at a broadband remote access server whether an elapsed time since a data packet is received with the particular MAC address exceeds a threshold time. If so, then point-to-point protocol (PPP) control data is sent in a data link protocol payload that is encapsulated in a data packet with an Ethernet destination field that indicates the particular MAC address. The PPP control data indicates a request for an echo. It is determined whether a data packet with the particular MAC address in an Ethernet source field is received within a particular time interval. If not, then a session associated with the particular MAC address is terminated. These techniques allow PPP control plane functionality while utilizing IP over Ethernet for the data plane.

Claims

1. A method, comprising:

receiving a particular inbound data packet of a first data link protocol, the particular inbound packet including particular header data and a payload of the first data link protocol, wherein the payload of the first data link protocol contains point-to-point protocol (PPP) data plane data from particular PPP data traffic, the particular header data including an identification of a particular media access control (MAC) address;

receiving another inbound data packet of a second data link protocol different from the data packet of the first data link protocol, the other inbound packet including other header data and a payload of the second data link protocol, the other header data including an identification of the particular MAC address, wherein the payload of the second data link protocol contains particular PPP control plane data from the particular PPP data traffic, wherein the particular and other inbound data packets were generated by splitting the PPP data traffic;

determining that an elapsed time since a latter of the particular and other inbound data packets was received exceeds a threshold time;

sending other PPP control data in a particular data link protocol payload that is encapsulated in an outbound data packet with an Ethernet destination field that indicates the particular MAC address, wherein the other PPP control data indicates a request for an echo; and

determining that a data packet with the particular MAC address in an Ethernet source field is received within a particular time interval, wherein receiving the data packet within the particular time interval is used as a basis for presuming that a persistent session is active and prompts a new time window to be initiated for determining whether the persistent session continues to be active.

4. The method of claim 1, wherein failures to detect a response from requests for an echo are used as a basis for terminating corresponding persistent sessions.

5. The method of claim 1, further comprising using the particular PPP control data to authenticate a user.

6. The method of claim 1, further comprising using the particular PPP control data to test a performance metric of a link associated with the persistent session.

7. The method of claim 1, wherein the particular header data includes a type field indicating that PPP data plane data is contained in the payload of the first data link protocol.

8. The method of claim 1, wherein the other header data includes a type field indicating that the PPP control plane data is contained in the payload of the second data link protocol.

9. The method of claim 8, further comprising determining, from the other header data, that the other inbound data packet includes PPP control plane data.

10. The method of claim 1, wherein each of the particular and other header data exclude at least a portion of point-to-point protocol over Ethernet (PPPoE) protocol header data.

11. The method of claim 1, wherein the first data link protocol comprises IP-over-Ethernet.

12. The method of claim 11, wherein the PPP data plane data comprises an IP datagram from a PPP payload of the PPP traffic.

13. The method of claim 1, wherein the second data link protocol is a modified Ethernet protocol.

14. The method of claim 1, wherein the particular and other inbound data packets and received substantially simultaneously.

2. An apparatus, comprising:

a network interface that is coupled to a network for communicating one or more packet flows therewith;

one or more processors; and

one or more stored sequences of instructions which, when executed by the one or more processors, causes the one or more processors to carry out the steps of;

receiving a particular inbound data packet of a first data link protocol, the particular inbound packet including particular header data and a payload of the first data link protocol, wherein the payload of the first data link protocol contains point-to-point protocol (PPP) data plane data from particular PPP data traffic, the particular header data including an identification of a particular media access control (MAC) address;

receiving another inbound data packet of a second data link protocol different from the data packet of the first data link protocol, the other inbound packet including other header data and a payload of the second data link protocol, the other header data including an identification of the particular MAC address, wherein the payload of the second data link protocol contains particular PPP control plane data from the particular PPP data traffic, wherein the particular and other inbound data packets were generated by splitting the PPP data traffic;

determining that an elapsed time since a latter of the particular and other inbound data packets was received exceeds a threshold time;

sending other PPP control data in a particular data link protocol payload that is encapsulated in an outbound data packet with an Ethernet destination field that indicates the particular MAC address, wherein the other PPP control data indicates a request for an echo; and

determining that a data packet with the particular MAC address in an Ethernet source field is received within a particular time interval, wherein receiving the data packet within the particular time interval is used as a basis for presuming that a persistent session is active and prompts a new time window to be initiated for determining whether the persistent session continues to be active.

3. A computer readable non-transitory medium including sequences of instructions such that when executed are configured for:

receiving a particular inbound data packet of a first data link protocol, the particular inbound packet including particular header data and a payload of the first data link protocol, wherein the payload of the first data link protocol contains point-to-point protocol (PPP) data plane data from particular PPP data traffic, the particular header data including an identification of a particular media access control (MAC) address;

receiving another inbound data packet of a second data link protocol different from the data packet of the first data link protocol, the other inbound packet including other header data and a payload of the second data link protocol, the other header data including an identification of the particular MAC address, wherein the payload of the second data link protocol contains particular PPP control plane data from the particular PPP data traffic, wherein the particular and other inbound data packets were generated by splitting the PPP data traffic;

determining that an elapsed time since a latter of the particular and other inbound data packets was received exceeds a threshold time;

sending other PPP control data in a particular data link protocol payload that is encapsulated in an outbound data packet with an Ethernet destination field that indicates the particular MAC address, wherein the other PPP control data indicates a request for an echo; and

determining that a data packet with the particular MAC address in an Ethernet source field is received within a particular time interval, wherein receiving the data packet within the particular time interval is used as a basis for presuming that a persistent session is active and prompts a new time window to be initiated for determining whether the persistent session continues to be active.