MLPoE at PTA
The Multilink PPP over Ethernet (MLPoE) at PPP Termination and Aggregation (PTA) feature allows customer premises equipment (CPE) and PTA devices to interleave high-priority and low-latency packets (PPP encapsulated) between Multilink PPP fragments of lower-priority and higher-latency packets.
- Finding Feature Information
- Prerequisites for MLPoE at PTA
- Restrictions for MLPoE at PTA
- Information About MLPoE at PTA
- How to Configure MLPoE at PTA
- Configuration Examples for MLPoE at PTA
- Additional References for MLPoE at PTA
- Feature Information for MLPoE at PTA
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and 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.
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 MLPoE at PTA
Before configuring Multilink PPP over Ethernet (MLPoE) at PPP termination and aggregation (PTA), you must complete the following tasks:
Creating a Class Map
Creating a Policy Map
Defining a PPP over Ethernet Profile
Configuring a Virtual Template Interface
For more information see Configuring Multilink PPP over Broadband section.
Restrictions for MLPoE at PTA
- In-Service Software Upgrade (ISSU) and Stateful Switchover (SSO) for Broadband MLP sessions are not supported.
- Multilink PPP over Ethernet (MLPoE) using EtherChannel is not supported.
- Cisco IOS XE software supports a maximum of 4000 member links using MLPoE.
- For MLP virtual access bundles, the default Layer 3 (that is IP, IPv6) maximum transmission unit (MTU) value is 1500. When the member link of the MLPPP bundle are Ethernet-like in MLPoEoE, MLPoEoVLAN, and MLPoEoQinQ, the MTU value of 1500 can cause an issue when sending IP packets close to this size. For example, when a 1500-byte IP packet is sent by a device over MLPoEoE, the actual packet size transmitted is 1522: 14 (Ethernet header) + 8 (PPPoE header) + 6 (MLP header) + 1500 (IP) = 1528. A device enforcing MRU might drop the incoming packet as a "giant" because it exceeds the default expected maximum packet size. The 1500-byte MTU size does not take into account any PPPoE or MLP header overhead and, hence, causes packets greater than 1492 bytes to be dropped by the peer. To address this issue, do one of the following:
- Member Link Session bandwidth—For MLPoE PPP termination and aggregation (PTA) variations, by default the bandwidth of the member link session is that of the parent interface. If a bandwidth statement is added to the virtual template, the member link session uses that bandwidth as the member link session bandwidth. This bandwidth is in turn communicated to MLPPP in the bundle member link aggregate data rate bandwidth calculation.
- If the Digital Subscriber Line Access Multiplexer (DSLAM) between the CPE and PTA communicates the link rate via the PPPoE dsl-sync-rate tags (Actual Data-Rate Downstream [0x82/130d] tag), this data is passed by the PTA device to the RADIUS server but is not acted upon by the ASR 1000 device. The data rate of the session remains as described above in the previous bullet. Note that this behavior is specific to PTA mode; LAC/LNS behaves differently. Use the dsl line info forwarding command on the LAC to transport the LAC access speed to the LNS.
Information About MLPoE at PTA
MLPoE at PTA Overview
Single-link PPP over Ethernet and Multilink PPP over Ethernet (MLPoE) bundles support upstream and downstream link fragmentation and interleaving (LFI). Upstream refers to the traffic from the customer premises equipment (CPE) and downstream refers to the traffic to the CPE. The receiving device (CPE for downstream and PPP termination and aggregation [PTA] for upstream) reassembles fragmented, nonpriority packets. To reduce any delay in forwarding high-priority packets, the receiving device processes high-priority PPP packets as soon as they arrive.
The figure below shows a sample MLPoE network with LFI.
PPP over Ethernet (PPPoE) sessions in MLPoE on a PTA device are handled as follows:
All supported variations of PPPoE, such as PPP over Ethernet over ATM (PPPoEoA), PPP over Ethernet over Ethernet (PPPoEoE), PPP over Ethernet over Queue-in-Queue (PPPoEoQinQ), and PPP over Ethernet over VLAN (PPPoVLAN), can be used as member links for MLPoE bundles.
Termination of an MLPoE bundle in a virtual routing and forwarding (VRF) block is similar to terminating a PPPoE session in a VRF instance.
MLPoE bundles are distinguished by the username that was used to authenticate the PPPoE member link session.
How to Configure MLPoE at PTA
Configuring MLPoE at PTA
1.
enable
2.
configure
terminal
3.
interface
type
number
4.
negotiation
auto
5.
pppoe
enable
group
group-name
6.
end
DETAILED STEPS
Configuring MLPoE over VLAN
1.
enable
2.
configure
terminal
3.
interface
type
number
4.
encapsulation
dot1q
vlan-id
5.
pppoe
enable
group
group-name
6.
end
DETAILED STEPS
Configuring MLPoE over QinQ
1.
enable
2.
configure
terminal
3.
interface
type
number
4.
encapsulation
dot1q
vlan-id
second-dot1q
{any |
vlan-id |
vlan-id-vlan-id | [,
vlan-id-vlan-id]}
5.
pppoe
enable
group
group-name
6.
end
DETAILED STEPS
Configuration Examples for MLPoE at PTA
Example: Configuring MLPoE at PTA
The following example shows how to configure the Multilink PPP over Ethernet (MLPoE) on the PTA device:
class-map match-all ip-prec-1 match ip precedence 1 ! policy-map mlp-child-lfi-policy class ip-prec-1 priority percent 10 policy-map mlp-parent-250K class class-default shape average 250000 service-policy mlp-child-lfi-policy policy-map mlp-parent-10M class class-default shape average 10000000 service-policy mlp-child-lfi-policy interface virtual-template 15 description MLPoE/oEoVLAN/oEoQinQ (single-link bundle) Virtual Template ip address negotiated peer default ip address pool MLP-IPv4-Pool ppp max-failure 30 ppp chap password 0 passowrd1 ppp multilink ppp multilink interleave ppp multilink endpoint magic-number ppp timeout retry 4 service-policy output mlp-parent-10M bba-group pppoe mlpoe-bba-group-10M virtual-template 15 ip local pool MLP-IPv4-Pool 209.165.201.2 209.165.201.10 interface GigabitEthernet 0/0/0 description MLPoE (Single-Link Bundles) Session (PTA Mode) to 7200-41 0/1 no ip address negotiation auto pppoe enable group mlpoe-bba-group-10M
Example: Configuring MLPoE over VLAN
The following example shows how to configure Multilink PPP over Ethernet over VLAN (MLPoEoVLAN) on the PTA device:
class-map match-all ip-prec-1 match ip precedence 1 policy-map mlp-child-lfi-policy class ip-prec-1 priority percent 10 policy-map mlp-parent-250K class class-default shape average 250000 service-policy mlp-child-lfi-policy policy-map mlp-parent-10M class class-default shape average 10000000 service-policy mlp-child-lfi-policy interface virtual-template 15 description MLPoE/oEoVLAN/oEoQinQ (single-link bundle) Virtual Template ip address negotiated peer default ip address pool MLP-IPv4-Pool ppp max-failure 30 ppp chap password 0 password1 ppp multilink ppp multilink interleave ppp multilink endpoint magic-number ppp timeout retry 4 service-policy output mlp-parent-10M bba-group pppoe mlpoe-bba-group-10M virtual-template 15 ip local pool MLP-IPv4-Pool 209.165.201.2 209.165.201.10 interface GigabitEthernet 0/0/0.13 description MLPoEoVLAN Session (Single-Link Bundles) Session (PTA Mode) encapsulation dot1Q 13 pppoe enable group mlpoe-bba-group-10M
Example: Configuring MLPoE over QinQ
The following example shows how to configure Multilink PPP over Ethernet over Queue-in-Queue (MLPoEoQinQ) on the PTA device:
class-map match-all ip-prec-1 match ip precedence 1 policy-map mlp-child-lfi-policy class ip-prec-1 priority percent 10 policy-map mlp-parent-250K class class-default shape average 250000 service-policy mlp-child-lfi-policy policy-map mlp-parent-10M class class-default shape average 10000000 service-policy mlp-child-lfi-policy interface virtual-template 15 description MLPoE/oEoVLAN/oEoQinQ (single-link bundle) Virtual Template ip address negotiated peer default ip address pool MLP-IPv4-Pool ppp max-failure 30 ppp chap password 0 password1 ppp multilink ppp multilink interleave ppp multilink endpoint magic-number ppp timeout retry 4 service-policy output mlp-parent-10M bba-group pppoe mlpoe-bba-group-10M virtual-template 15 ip local pool MLP-IPv4-Pool 40.1.0.1 40.1.0.6 interface GigabitEthernet 0/0/0.14 description MLPoEoQinQ Sessions (Single-Link Bundles) Session (PTA Mode) encapsulation dot1Q 14 second-dot1q 140 pppoe enable group mlpoe-bba-group-10M
Additional References for MLPoE at PTA
Related Documents
Related Topic |
Document Title |
---|---|
Cisco IOS commands |
|
PPP commands |
|
Multilink PPP |
Multilink PPP Feature Functionality on the ASR 1000 Series Aggregation Services Router |
Standards and RFCs
Standard/RFC |
Title |
---|---|
RFC 1990 |
The PPP Multilink Protocol (MP) |
RFC 2686 |
The Multi-Class Extension to Multi-Link PPP |
MIBs
Technical Assistance
Description |
Link |
---|---|
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
Feature Information for MLPoE at PTA
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.
Feature Name |
Releases |
Feature Information |
---|---|---|
MLPoE at PTA |
12.2(33)XNE Cisco IOS XE Release 3.4S Cisco IOS XE Release 3.10S Cisco IOS XE Release 3.12S |
Multilink PPP over Ethernet (MLPoE) at PPP Termination and Aggregation (PTA) feature allows the customer premises equipment (CPE) and PTA devices to interleave high-priority and low-latency packets (PPP encapsulated) between MLPPP fragments of lower-priority and higher-latency packets. |