Understanding Pfc3Bxl Or Pfc3B Mode Mpls Qos; Lers At The Eompls Edge - Cisco 7604 Configuration Manual
Ios software configuration guide
Hide thumbs
Also See for 7604:
- Configuration manual (742 pages) ,
- Installation manual (324 pages) ,
- User manual (98 pages)
Table of Contents
Advertisement
Understanding PFC3BXL or PFC3B Mode MPLS QoS
Understanding PFC3BXL or PFC3B Mode MPLS QoS
PFC3BXL or PFC3B mode MPLS QoS supports IP QoS. For MPLS packets, the EXP value is mapped
into an internal DSCP so that the PFC3BXL or PFC3B can apply non-MPLS QoS marking and policing.
For both the ingress and egress policies, PFC3BXL or PFC3B mode MPLS QoS marking and policing
decisions are made on a per-interface basis at an ingress PFC3BXL or PFC3B. The ingress interfaces are
physical ports, subinterfaces, or VLANs.
The QoS policy ACLs are programmed in QoS TCAM separately for ingress and egress lookup. The
ternary content addressable memory (TCAM) egress lookup takes place after the IP forwarding table
(FIB) and NetFlow lookups are completed.
The results of each QoS TCAM lookup yield an index into RAM that contains policer configuration and
policing counters. Additional RAM contains the microflow policer configuration; the microflow
policing counters are maintained in the respective NetFlow entries that match the QoS ACL.
The results of ingress and egress aggregate and microflow policing are combined into a final policing
decision. The out-of-profile packets can be either dropped or marked down in the DSCP.
This section describes PFC3BXL or PFC3B mode MPLS QoS for the following:
•
•
•
The following sections refer to QoS features for LAN ports, OSM ports, and FlexWAN ports. For details
Note
about how the different features work, refer to the appropriate documentation.
LERs at the EoMPLS Edge
This section summarizes the Ethernet over MPLS (EoMPLS) QoS features that function on the LERs.
EoMPLS QoS support is similar to IP-to-MPLS QoS:
•
•
•
•
•
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
42-8
LERs at the EoMPLS Edge, page 42-8
LERs at the IP Edge (MPLS, MPLS VPN), page 42-9
LSRs at the MPLS Core, page 42-13
For EoMPLS, if the port is untrusted, the CoS trust state is automatically configured for VC type 4
(VLAN mode), not for VC type 5 (port mode). 802.1q CoS preservation across the tunnel is similar.
Packets received on tunnel ingress are treated as untrusted for EoMPLS interfaces, except for VC
Type 4 where trust CoS is automatically configured on the ingress port and policy marking is not
applied.
If the ingress port is configured as trusted, packets received on an EoMPLS interface are never
marked by QoS policy in the original IP packet header (marking by IP policy works on untrusted
ports).
802.1p CoS is preserved from entrance to exit, if available through the 802.1q header.
After exiting the tunnel egress, queueing is based on preserved 802.1p CoS if 1p tag has been
tunnelled in the EoMPLS header (VC type 4); otherwise, queuing is based on the CoS derived from
the QoS decision.
Chapter 42
Configuring PFC3BXL or PFC3B Mode MPLS QoS
OL-4266-08
- Quick Links:
- Supported Hardware and Software
Hide quick links:
Advertisement
Chapters
Table of Contents
