Configuring Traffic Class Maps to Manage Ingress Oversubscription
On T4000 routers with Type 5 FPCs and on MX Series routers with
MPCs, you can prioritize and classify the traffic entering a Packet
Forwarding Engine by configuring a traffic class map based on CoS
code points and associating the code points with a particular traffic
class, such as network-control, best-effort,
or real-time. During ingress oversubscription, the router
uses this traffic class map to identify the class type to forward
or drop the packets.
To configure a traffic class map:
- Configure the interface. This interface needs
to be associated with the configured traffic class maps.
[edit ] user@host# set interfaces interface-name unit unit-number family family-name address address
- Create a traffic class map based on CoS code points and
map the code points to a traffic class to decide the input packet
priority.
To create a DiffServ code point (DSCP) traffic class map and map the code points to a traffic class for IPv4 and IPv6 traffic, include the following statements at the
[edit class-of-service]hierarchy level.[edit class-of-service] user@host# set traffic-class-map dscp traffic-class-map-name traffic-class best-effort code-points code-point-value user@host# set traffic-class-map dscp traffic-class-map-name traffic-class network-control code-points code-point-value user@host# set traffic-class-map dscp traffic-class-map-name traffic-class real-time code-points code-point-value
To create an IEEE 802.1 traffic class map and map the code points to a traffic class, include the following statements at the
[edit class-of-service]hierarchy level.[edit class-of-service] user@host# set traffic-class-map ieee-802.1 traffic-class-map-name traffic-class best-effort code-points code-point-value user@host# set traffic-class-map ieee-802.1 traffic-class-map-name traffic-class network-control code-points code-point-value user@host# set traffic-class-map ieee-802.1 traffic-class-map-name traffic-class real-time code-points code-point-value
To create an MPLS EXP traffic class map and map the code points to a traffic class, include the following statements at the
[edit class-of-service]hierarchy level.[edit class-of-service] user@host# set traffic-class-map exp traffic-class-map-name traffic-class best-effort code-points code-point-value user@host# set traffic-class-map exp traffic-class-map-name traffic-class network-control code-points code-point-value user@host# set traffic-class-map exp traffic-class-map-name traffic-class real-time code-points code-point-value
To create an IPv4 precedence traffic class map and map the code points to a traffic class, include the following statements at the
[edit class-of-service]hierarchy level.[edit class-of-service] user@host# set traffic-class-map inet-precedence traffic-class-map-name traffic-class best-effort code-points code-point-value user@host# set traffic-class-map inet-precedence traffic-class-map-name traffic-class network-control code-points code-point-value user@host# set traffic-class-map inet-precedence traffic-class-map-name traffic-class real-time code-points code-point-value
To create an IEEE 802.1ad code point traffic class map and map the code points to a traffic class, include the following statements at the
[edit class-of-service]hierarchy level.[edit class-of-service] user@host# set traffic-class-map ieee-802.1ad traffic-class-map-name traffic-class best-effort code-points code-point-value user@host# set traffic-class-map ieee-802.1ad traffic-class-map-name traffic-class network-control code-points code-point-value user@host# set traffic-class-map ieee-802.1ad traffic-class-map-name traffic-class real-time code-points code-point-value
- Associate the traffic class map with the interface that
is configured in Step 1.
Associate the DSCP traffic class map with the interface.
[edit class-of-service] user@host# set interfaces interface-name traffic-class-map dscp traffic-class-map-name
Associate the IEEE 802.1 traffic class map with the interface.
[edit class-of-service] user@host# set interfaces interface-name traffic-class-map ieee-802.1 traffic-class-map-name <vlan-tag (inner | outer)>
Associate the MPLS EXP traffic class map with the interface.
[edit class-of-service] user@host# set interfaces interface-name traffic-class-map exp traffic-class-map-name
Associate the IPv4 precedence traffic class map with the interface.
[edit class-of-service] user@host# set interfaces interface-name traffic-class-map inet-precedence traffic-class-map-name
Associate the IEEE 802.1ad traffic class map with the interface.
[edit class-of-service] user@host# set interfaces interface-name traffic-class-map ieee-802.1ad traffic-class-map-name <vlan-tag (inner | outer)>
Note:If you do not associate the traffic class map with the configured interface, all traffic through this interface is treated with the existing fixed rule in the Packet Forwarding Engine, which prioritizes network control traffic over best-effort traffic.
As soon as you associate a traffic class map with an interface, any code points entering that interface and not included in the traffic class map are treated as best effort.
You can associate either an IPv4 precedence traffic class map or a DSCP traffic class map with an interface. You cannot associate both these traffic class maps with a single interface. The DSCP traffic class map applies to both IPv4 and IPv6 traffic.
You can associate either an IEEE 802.1 traffic class map or an IEEE 802.1ad traffic class map with an interface. You cannot associate both these traffic class maps with a single interface.
An aggregated Ethernet interface bundle can have member links from both interfaces that support traffic class maps and interfaces that do not. A configured traffic class map is associated with an aggregated Ethernet bundle in following ways:
If an aggregated Ethernet bundle has child links only from interfaces that support traffic class maps, then the traffic class map is associated with all links of the aggregated Ethernet bundle.
If an aggregated Ethernet bundle has child links only from interfaces that do not support traffic class maps, then the traffic class map is not associated with the aggregated Ethernet bundle or its links.
If an aggregated Ethernet bundle has child links from both interfaces that support traffic class maps and interfaces that do not, the traffic class map is associated only with the links from the interfaces that support traffic class maps.