- Preparing for Broadband Access Aggregation
- Providing Protocol Support for Broadband Access Aggregation of PPPoE Sessions
- PPPoE Session Limit Local Override
- PPPoE Circuit-Id Tag Processing
- Configuring PPP over Ethernet Session Limit Support
- PPP-Max-Payload and IWF PPPoE Tag Support
- PPPoE QinQ Support
- PPPoE Session Limiting on Inner QinQ VLAN
- PPPoE Agent Remote-ID and DSL Line Characteristics Enhancement
- Enabling PPPoE Relay Discovery and Service Selection Functionality
- Configuring Cisco Subscriber Service Switch Policies
- Per Session Queueing and Shaping for PPPoEoVLAN Using RADIUS
- 802.1P CoS Bit Set for PPP and PPPoE Control Frames
- PPPoE Smart Server Selection
- Monitoring PPPoE Sessions with SNMP
- PPPoE on ATM
- PPPoE on Ethernet
- Remote Access MPLS VPNs
- Broadband High Availability Stateful Switchover
- Broadband High Availability In-Service Software Upgrade
- Controlling Subscriber Bandwidth
- PPPoE Service Selection
- Finding Feature Information
- Prerequisites for 802.1P CoS Bit Set for PPP and PPPoE Control Frames
- Restrictions for 802.1P CoS Bit Set for PPP and PPPoE Control Frames
- Information About 802.1P CoS Bit Set for PPP and PPPoE Control Frames
- How to Configure 802.1P CoS Bit Set for PPP and PPPoE Control Frames
- Configuration Examples for 802.1P CoS Bit Set for PPP and PPPoE Control Frames
- Additional References
- Feature Information for 802.1P CoS Bit Set for PPP and PPPoE Control Frames
802.1P CoS Bit Set for PPP and PPPoE Control Frames
The 802.1P CoS Bit Set for PPP and PPPoE Control Frames feature provides the ability to set user priority bits in the IEEE 802.1Q tagged frame to allow traffic prioritization. This capability enables a way to provide best-effort quality of service (QoS) or class of service (CoS) at Layer 2 without requiring reservation setup.
- Finding Feature Information
- Prerequisites for 802.1P CoS Bit Set for PPP and PPPoE Control Frames
- Restrictions for 802.1P CoS Bit Set for PPP and PPPoE Control Frames
- Information About 802.1P CoS Bit Set for PPP and PPPoE Control Frames
- How to Configure 802.1P CoS Bit Set for PPP and PPPoE Control Frames
- Configuration Examples for 802.1P CoS Bit Set for PPP and PPPoE Control Frames
- Additional References
- Feature Information for 802.1P CoS Bit Set for PPP and PPPoE Control Frames
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 802.1P CoS Bit Set for PPP and PPPoE Control Frames
The PPPoE over 802.1Q VLAN feature must be enabled.
Restrictions for 802.1P CoS Bit Set for PPP and PPPoE Control Frames
You cannot set different CoS levels for PPP and Point-to-Point Protocol over Ethernet (PPPoE) control packets; all control packets default to a CoS level set at 0.
Information About 802.1P CoS Bit Set for PPP and PPPoE Control Frames
To configure the 802.1P CoS Bit Set for PPP and PPPoE Control Frames feature, you should understand the following concepts:
The command can help troubleshoot 802.1P control frame marking: debug pppoe error
- Benefits of 802.1P CoS Bit Set for PPP and PPPoE Control Frames
- Feature Design of 802.1P CoS Bit Set for PPP and PPPoE Control Frames
Benefits of 802.1P CoS Bit Set for PPP and PPPoE Control Frames
The 802.1P CoS Bit Set for PPP and PPPoE Control Frames feature facilitates moving from ATM-based to Ethernet-based networks by supporting the ability to offer prioritized traffic services, Voice over Internet Protocol (VoIP), and other premium services.
Feature Design of 802.1P CoS Bit Set for PPP and PPPoE Control Frames
The IEEE 802.1P specification is an extension of the IEEE 802.1Q VLANs tagging standard and enables Layer 2 devices to prioritize traffic by using an 802.1P header that includes a three-bit user priority field. If congestion occurs when the 802.1P CoS bit is not set, PPP keepalive packets can be lost, which can result in disconnection of an established session with loss of service to the end user. Congestion caused by noncontrol packets can also prevent new sessions from being established, which also can result in denying service to the end user.
PPPoE sessions established over 802.1Q VLANs use the priority header field to provide best-effort QoS or CoS at Layer 2 without involving reservation setup. 802.1P traffic is marked and sent to the destination, and no bandwidth reservations are established.
In Cisco IOS XE Release 2.4, PPPoE sessions established over IEEE 802.1Q VLAN make use of the priority field of the IEEE 802.1p header by setting the CoS field to user priority 7.
During network congestion, when the Ethernet network and digital subscriber line access multiplexer (DSLAM) offer 802.1P support, control packets are offered a higher priority than noncontrol packets, thereby increasing the likelihood of reliable delivery. PPPoE control packets and PPP packets originating from the broadband remote access server (BRAS) are marked with user priority 0, the highest level of priority.
The following packets are tagged with user priority 0 in their 802.1P header:
How to Configure 802.1P CoS Bit Set for PPP and PPPoE Control Frames
The 802.1P CoS Bit Set for PPP and PPPoE Control Frames feature is enabled by default and requires no configuration.
Configuration Examples for 802.1P CoS Bit Set for PPP and PPPoE Control Frames
The following task explains how to change the CoS setting for PPP and PPPoE control frames over 802.1Q VLAN.
Setting 802.1P Priority Bits in 802.1Q Frames Containing PPPoE Control Packets
This task explains how to change the CoS settings for PPP and PPPoE control frames over 802.1Q VLAN.
DETAILED STEPS
Additional References
The following sections provide references related to the 802.1P CoS Bit Set for PPP and PPPoE Control Frames feature.
Related Documents
Related Topic |
Document Title |
---|---|
Broadband access aggregation concepts |
Cisco IOS XE Broadband and DSL Configuration Guide |
Broadband access commands |
Cisco IOS Broadband Access Aggregation and DSL Command Reference |
Standards
Standard |
Title |
---|---|
IEEE Standard 802.1P |
PPPoE over IEEE 802.1Q |
IEEE Standard 802.1Q |
Virtual Bridged Local Area Networks |
MIBs
MIB |
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 XE software releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFCs
RFC |
Title |
---|---|
RFC 2516 |
PPP over Ethernet |
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. |
Feature Information for 802.1P CoS Bit Set for PPP and PPPoE Control Frames
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 802.1P CoS Bit Set for PPP and PPPoE Control Frames |
Feature Name |
Releases |
Feature Information |
---|---|---|
802.1P CoS Bit Set for PPP and PPPoE Control Frames |
Cisco IOS XE Release 2.4 |
The 802.1P CoS Bit Set for PPP and PPPoE Control Frames feature provides the ability to set user priority bits in the IEEE 802.1Q tagged frame to allow traffic prioritization. This capability enables a way to provide best-effort QoS or CoS at Layer 2 without requiring reservation setup. In Cisco IOS XE Release 2.4, this feature was introduced. The following command was introduced: control-packets vlan cos. |
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.