Layer 2 Control Processing (L2Cp) - Alcatel-Lucent 7210 Sas-x Service Manual

Layer 2 Control Processing (L2CP)

Operators providing Epipe service need to be able to transparently forward Layer-2 control frames
received from the customers. This allows their customers to run these control protocols between
the different locations which are part of the L2 VPN service. The 7210 SAS platforms provide
user with the following capability:
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NOTE: The CDP, VTP, DTP, PgAP, and UDLD management protocols, are forwarded
transparently in an Epipe service.
By default, LACP, LLDP, EFM OAM, and Dot1x Layer-2 control protocol untagged packets are
discarded if the protocol is not enabled on the port where these frames are received. User has an
option to enable peering by enabling the protocol on the port and configuring the appropriate
parameters for the protocol. User also has an option to tunnel these packets using an Epipe or
VPLS service.
In a VPLS service, the layer-2 control frames are sent out of all the SAPs configured in the VPLS
service. It is recommended to use this feature carefully and only when an VPLS is used to emulate
an end-to-end Epipe service (that is, an Epipe configured using a 3-point VPLS Service, with one
access SAP and 2 access-uplink SAP/SDPs for redundant connectivity). In other words, if the
VPLS service is used for multipoint connectivity, it is not recommended to use this feature. When
a layer-2 control frame is forwarded out of dot1q SAP or a QinQ SAP, the SAP tags of the egress
SAP are added to the packet.
The following SAPs can be configured for tunneling the untagged L2CP frames (corresponding
protocol tunneling needs to be enabled on the port):
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In addition to the protocols listed above, protocols that are not supported on 7210, For example:
GARP, GVRP, ELMI, and others are transparently forwarded in case of a VPLS service. These
protocols are transparently forwarded if a NULL SAP, dot1q default SAP , dot1q explicit null SAP
or 0.* SAP is configured on the port and received packet is untagged. If the received packet is
tagged and matches the tag of any of the SAPs configured on the port, it is forwarded in the
7210 SAS-X, R6 OS Services Guide
An option to tunnel, discard or peer for EFM OAM, LLDP, Dot1x, and LACP.
BPDU translation and Layer 2 Protocol Tunnelling support for xSTP and CISCO control
protocols. This is supported only in a VPLS service. For more information, see the
and BPDU Translation on page
If the port encapsulation is null, user has an option to tunnel these packets by configuring
a NULL SAP on a port
If the port encapsulation is dot1q, user an option to use dot1q explicit null SAP (e.g. 1/1/
10:0) or a dot1q default SAP (For example: 1/1/11:*) to tunnel these packets.
If the port encapsulation is QinQ, user has an option to use 0.* SAP (For example 1/1/
10:0.*) to tunnel these packets.
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Services
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