Cisco 10000 Series User Manual

20-3
Cisco 10000 Series Router Quality of Service Configuration Guide
OL-7433-09
Chapter 20 Configuring Quality of Service for MPLS Traffic
MPLS QoS
MPLS Tunneling Modes
MPLS QoS provides QoS on MPLS packets using the following tunnel modes:
• Uniform—Provides uniformity in per-hop behavior (PHB) throughout the network. In this mode, all
customers of your MPLS network use the same precedence settings.
• Short Pipe—(Default) Provides for a distinct MPLS PHB layer (on top of the IP PHB layer) across
the entire MPLS network. In this mode, your customers implement their own IP PHB marking
scheme.
• Pipe—Similar to short pipe mode, except that at the egress of the provider edge (PE) router the
MPLS PHB layer is used to classify the packet for discard and scheduling behavior at the outbound
interface. In this mode, you schedule and discard packets without needing to know your customer
setting.
Figure 20-1 shows a service provider MPLS network that connects two sites of a customer’s network. To
use these features in a network, set the MPLS experimental field value at PE1 (the ingress label
switching router) by using the modular QoS CLI. This sets the QoS value in the MPLS packet.
Figure 20-1 MPLS Network Connecting Two Sites of a Customer's IP Network
Short pipe tunnel mode discards the MPLS EXP value on label disposition. To enable MPLS EXP-based
classification after label disposition, you can map the EXP values to the qos-group values at the inbound
interface and use qos-group to classify packets into different classes at the outbound interface. However,
Weighted Random Early Detection (WRED) on the outbound interface is still based on the IP type of
service (ToS) value rather than the disposed EXP value.
The Cisco 10000 series router does not support the propagate-cos command to enable uniform mode.
The router does not copy the MPLS EXP values on disposition to the packet’s IP header, unless you map
the EXP value to a qos-group value at the inbound interface and use the qos-group value to set the IP
ToS value on the outbound interface.
CE1
41867
PE1 P1 P2 PE2 CE2
IP
network
MPLS
network
IP
network
MPLS
network
Host A
Host B
Owned by
service provider

Cisco 10000 Series Specifications

General

Brand	Cisco
Model	10000 Series
Category	Network Router
Language	English