Upstream PPPoX Connection Speed Transfer at LAC

Last Updated: December 1, 2011

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.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the Feature Information Table at the end of this document.

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.

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

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

Configuring Upstream PPPoX Connection Speed Transfer at the LAC

The tasks in this section configure upstream PPPoX connection speed transfer at the LAC on a PVC or VC:

Configuring Upstream PPPoX Connection Speed Transfer at LAC on a PVC

Perform this task to configure the Upstream PPPoX Connection Speed Transfer feature at the LAC on a PVC.

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    interface atm slot / port . [subinterface-number{mpls | multipoint| point-to-point}]

4.    range [range-name] pvc start-vpi / start-vci end-vpi / end-vci

5.    rx-speed incoming-cell-rate

6.    exit


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 3
interface atm slot / port . [subinterface-number{mpls | multipoint| point-to-point}]


Example:

Router(config)# interface atm 2/0.1 multipoint

 

Enters subinterface configuration mode.

 
Step 4
range [range-name] pvc start-vpi / start-vci end-vpi / end-vci


Example:

Router(config-subif)# range pvc 0/100 0/110

 

Enters PVC-in-range configuration mode.

 
Step 5
rx-speed incoming-cell-rate


Example:

Router(config-if-atm-range)# rx-speed 128

 

Allows L2TP to send AV pair 38 with the given value to LNS.

  • The valid range for incoming-cell-ratefor L2TP AVP is from 0 to 44209 kb/s.
 
Step 6
exit


Example:

Router(config-if-atm-range)# exit

 

Exits PVC-in-range configuration mode.

 

Configuring Upstream PPPoX Connection Speed Transfer at LAC on VC

Perform this task to configure the Upstream PPPoX Connection Speed Transfer at LAC on a VC.

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    interface atm slot / port . [subinterface-number{mpls | multipoint | point-to-point}]

4.    pvc [name] {vpi/vci | vci} [ces | ilmi | qsaal | smds | l2transport]

5.    rx-speed incoming-cell-rate

6.    encapsulation {aal2 | aal5auto | aal5autoppp virtual-template number [group group-name] | aal5ciscoppp virtual-template number | aal5mux protocol | aal5nlpid | aal5snap}

7.    exit


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 3
interface atm slot / port . [subinterface-number{mpls | multipoint | point-to-point}]


Example:

Router(config)# interface atm 2/0.1 multipoint

 

Enters subinterface configuration mode.

 
Step 4
pvc [name] {vpi/vci | vci} [ces | ilmi | qsaal | smds | l2transport]


Example:

Router(config-subif)# pvc pvc1 0/100

 

Enters PVC-class configuration mode.

 
Step 5
rx-speed incoming-cell-rate


Example:

Router(config-if-atm-vc)# rx-speed 128

 

Allows L2TP to send (AV) pair 38 with the given value to LNS.

 
Step 6
encapsulation {aal2 | aal5auto | aal5autoppp virtual-template number [group group-name] | aal5ciscoppp virtual-template number | aal5mux protocol | aal5nlpid | aal5snap}


Example:

Router(config-if-atm-vc)# encapsulation aal5snap

 

Configures Logical Link Control (LLC) Subnetwork Access Protocol (SNAP) encapsulation on the PVC.

 
Step 7
exit


Example:

Router(config-if-atm-vc)# exit

 

Exits PVC-class configuration mode.

 

Configuration Examples for Upstream PPPoX Connection Speed Transfer at LAC

Configuring Upstream PPPoX Connection Speed Transfer at LAC Example

The following examples show how to configure the upstream PPPoX connection speed transfer at LAC in PVC, range PVC, and PVC-in-range modes.

PVC Class

interface atm 6/0.110 multipoint
 pvc 0/600
 rx-speed 128
  encapsulation aal5snap
  exit

Range PVC

interface atm 6/0.110 multipoint
 range range-pppoa-1 pvc 100 4/199
  rx-speed 400
 exit

PVC-in-Range

interface atm 6/0.110 multipoint
  range range1 pvc 100 4/199
 pvc-in-range 0/300
 rx-speed 200
 shutdown

Additional References

The following sections provide references related to the upstream PPPoX connection speed transfer.

Related Documents

Related Topic

Document Title

Configuring VC classes

"Configuring VC Classes" section in the "Configuring ATM" module in theCisco IOS Wide-Area Networking Configuration Guide .

Understanding the Unspecified Bit Rate+ (UBR+) service category for ATM VCs

"Understanding the UBR+ Service Category for ATM VCs" module in ATM (Asynchronous Transfer Mode) Technical Support

Broadband access aggregation concepts

Understanding Broadband Access Aggregation module

Preparing for broadband access aggregation task

Preparing for Broadband Access Aggregation module

BBDSL commands: complete command syntax, command mode, command history, defaults, usage guidelines, and examples

Cisco IOS Broadband Access Aggregation and DSL Command Reference

Cisco IOS commands

Cisco IOS Master Commands List, All Releases

Standards

Standards

Title

No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.

--

MIBs

MIBs

MIBs Link

No new or modified MIBs are supported by this feature, and support for existing MIBs has not been modified by this feature.

To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs

RFCs

RFCs

Title

RFC 2661

Layer 2 Tunneling Protocol "L2TP"

Technical Assistance

Description

Link

The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.

To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.

Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.

http://www.cisco.com/cisco/web/support/index.html

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.

Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL: www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1110R)

Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.

© 2011 Cisco Systems, Inc. All rights reserved.