Enterprise QoS Solution Reference Network Design Guide

Provider-Edge QoS Considerations
Pipe Mode
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Enterprise QoS Solution Reference Network Design Guide
Chapter 5 MPLS VPN QoS Design
conform-action set-mpls-exp-topmost-transmit 1 ! Conforming Bulk set to 1
exceed-action set-mpls-exp-topmost-transmit 6 ! Excess Bulk set to 6
class class-default
police cir 750000
conform-action set-mpls-exp-topmost-transmit 0 ! Conforming BE set to 0
exceed-action set-mpls-exp-topmost-transmit 4 ! Excess BE set to 4
!
…
!
interface FastEthernet1/0
description FE TO CUSTOMER RED CE ! Link to/from CE
ip vrf forwarding RED
ip address 10.1.12.2 255.255.255.0
service-policy input PE-FIVE-CLASS-SHORT-PIPE-MARKING
!
Verification commands:
show policy
show policy interface
The main difference between Short Pipe Mode and Pipe Mode MPLS DiffServ tunneling is that the PE
egress policies (toward the customer CEs) are provisioned according to the service provider’s explicit
markings and re-markings, not the enterprise customer’s IP DiffServ markings (although these are
preserved). As with Short Pipe Mode, any changes to label markings that occur within the service
provider’s cloud do not get propagated to the IP ToS byte when the packet leaves the MPLS network.
Because egress PE-to-CE QoS policies in Pipe Mode are dependent on the last MPLS EXP value, this
value must be preserved before the final label is popped. A temporary placeholder (as used in Uniform
Mode operation) is again required. On the final PE router in a given path, the MPLS EXP value is copied
to the QoS Group value. Optionally, a Discard Class value also might set drop preference at the same
time. Thereafter, egress queuing or dropping policies are performed based on these QoS Group/Discard Class
values. Figure 5-13 illustrates the Pipe Mode MPLS DiffServ tunneling operation.
Version 3.3