The Cisco CRS Router Carrier Ethernet Model
This module provides
the conceptual information for implementing Ethernet Flow Points (EFPs) on the
Feature History for
Implementing Ethernet Flow Point
||The EFP model was introduced on the Cisco CRS Router
An Ethernet Flow
Point (EFP) is a Layer 2 logical subinterface used to classify traffic under a
physical or a bundle interface. A physical interface can be an Ethernet
interface and has ports on the line card.
A bundle interface
is a virtual interface, created by grouping physical interfaces together. For
example, physical interfaces such as Gigabit Ethernet 0/0/0/1 and 10 Gigabit
Ethernet 0/0/0/0 can be configured as members of a bundle interface.
interfaces together can:
EFP has the
bandwidth of the bundle interface.
traffic on the bundle members.
represents a logical demarcation point of an Ethernet Virtual Connection (EVC)
on an interface. For an EVC associating two or more UNIs, there is a flow point
on each interface of every device, through which that EVC passes.
An EFP can be
regarded as an instantiation of a particular service. An EFP is defined by a
set of filters. These filters are applied to all the ingress traffic to
classify the frames that belong to a particular EFP. An EFP filter is a set of
entries, where each entry looks similar to the start of a packet (ignoring
source/destination MAC address). Each entry usually contains 0, 1 or 2 VLAN
tags. A packet that starts with the same tags as an entry in the filter is said
to match the filter; if the start of the packet does not correspond to any
entry in the filter then the packet does not match the filter.
An EFP serves
all frames that belong to a particular flow on a given interface
ingress and egress Ethernet header manipulations
features to the identified frames
define how to forward those frames in the data path.
EFP has the following characteristics:
You can perform a
variety of operations on the traffic flows when a router is configured with
EFPs on various interfaces. Also, you can bridge or tunnel the traffic by many
ways from one or more of the router's ingress EFPs to one or more egress EFPs.
This traffic is a mixture of VLAN IDs, single or double (QinQ) encapsulation,
The following figure
shows the EFP model.
An EFP subinterface
is configured to specify which traffic on ingress is vectored to that EFP. This
is done by specifying a VLAN ID or QinQ tagging to match against on ingress.
All traffic on ingress is compared to each EFP's matching criterion, and
processed by that EFP if a match occurs. The processing performed by an EFP can
change VLAN IDs, add or remove VLAN tags, and change ethertypes.
- This command identifies a subinterface (or a physical port or bundle-port
parent interface) as an EFP.
command - This command is used to specify matching criteria.
rewrite command -
This command is used to specify the VLAN tag rewrite criteria.