The Upstream PPPoX Connection Speed Transfer at LAC feature allows the transfer of the upstream PPPoX session speed value at the Layer 2 Tunnel Protocol (L2TP) access concentrator (LAC). This transfer is accomplished by configuring the required speed on the ATM virtual circuit (VC) carrying the PPPoX session and then transferring this information into attribute-value (AV) pair 38 for transport from the LAC to the L2TP network server (LNS).
Note
PPPoX is a term used to refer to PPPoE, PPPoA, and PPPoEoA. All are implementations of PPP over various delivery protocols such as Ethernet and ATM.
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Prerequisites for Upstream PPPoX Connection Speed Transfer at LAC
You must understand the concepts described in the
Preparing for Broadband Access Aggregation module.
You must establish PPPoE sessions using the procedures in the
Providing Protocol Support for Broadband Access Aggregation of PPPoE Sessions module.
Restrictions for Upstream PPPoX Connection Speed Transfer at LAC
The following restrictions apply to the Upstream PPPoX Connection Speed Transfer at LAC feature:
For PPPoE, all sessions over the same VC must have the same send and receive speed.
The upstream speed is informational and does not imply any policing or shaping of the session speed.
Information About Upstream PPPoX Connection Speed Transfer at LAC
The send speed from the LAC to the remote destination is copied into AV pair 38 so that the session is symmetric at the LNS. The LNS does not do any policing of the upstream rate but verifies the session speed against the Service Level Agreement (SLA) before accepting it.
The transfer of the upstream PPPoX session speed at the LAC is done by:
Configuring the required speed on the ATM virtual circuit carrying the PPPoX session.
Transferring the information to AV pair 38 for transport from the LAC to the LNS.
The figure below shows how the Upstream PPPoX Connection Speed Transfer at LAC feature works.
Figure 1
Upstream PPPoX Connection Speed Transfer at LAC
Benefits of Upstream PPPoX Connection Speed Transfer at LAC
The Upstream PPPoX Connection Speed Transfer at LAC feature enables the configuration of an upstream PPPoX session speed, which is different from the downstream speed and allows the transfer of the upstream speed value from the LAC to the LNS. The default state (before this feature is enabled) is that the upstream speed and the downstream speed are the same. This feature implements changes that allows asymmetry in the upstream and downstream speeds.
This feature provides the following benefits:
Allows support for asymmetric broadband service speeds such as asymmetric digital subscriber line (ADSL).
Complies with RFC 2661 for L2TP.
Is required for regulatory compliance in certain European countries; for example, Germany.
How to Configure Upstream Connection Speed Transfer at LAC
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Feature Information for Upstream PPPoX Connection Speed Transfer at LAC
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to
www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 1
Feature Information for Upstream PPPoX Connection Speed Transfer at LAC
Feature Name
Releases
Feature Information
Upstream PPPoX Connection Speed Transfer at LAC
12.2(15)B 12.2(4)T 12.2(33)SRE
The Upstream PPPoX Connection Speed Transfer at LAC feature allows the transfer of the upstream PPPoX session speed value at the LAC.
The following command was introduced:rx-speed.
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