Figure 14: Mpls-Tp Pw Information Model - Alcatel-Lucent 7450 Manual

MEPs
T-PE X
global_id
node_id
In the PW information model shown in
is composed of the full AGI:SAII:TAII. The PW Path ID is also the MEP ID at the T-PEs, so a
user does not have to explicitly configure a MEP ID; it is automatically derived by the system. For
MPLS-TP PWs with static labels, although the PW is not signaled end-to-end, the directionality of
the SAII and TAII is taken to be the same as for the equivalent label mapping message i.e. from
downstream to upstream. This is to maintain consistency with signaled pseudowires using FEC
129.
On the system, an S-PE for an MS-PW with static labels is configured as a pair of spoke-sdps
bound together in an VLL service using the VC-switching command. Therefore, the PW Path ID
configured at the spoke-SDP level at an S-PE must contain the Global-ID, Node-ID and AC-ID at
the far end T-PEs, not the local S-PE. Note that the ordering of the SAII:TAII in the PW Path ID
where static PWs are used should be consistent with the direction of signaling of the egress label
to a spoke-SDP forming that segment, if that label were signaled using T-LDP (in downstream
unsolicited mode). VCCV Ping will check the PW ID in the VCCV Ping echo request message
against the configured PW Path ID for the egress PW segment.
Figure 15
MS-PW.
7450 ESS MPLS Guide
pw_path_id =
agi::saii::taii
MIP
PW_a
Primary
S-PE A
MIP
PW_b
Secondary
S-PE C

Figure 14: MPLS-TP PW Information Model

shows an example of how the PW Path IDs can be configured for a simple two-segment
MIP
mip_id =
node_id::0
S-PE B
MIP
Note: PW Path ID is Structured
as per FEC129 All Type 2
S-PE D
Figure 14, the MS-PW is identified by the PW Path ID that
MPLS and RSVP
MEG
MEPs
meg_id =
pw_path_id
mep_id =
agi::global_id::
node_id::ac_id
T-PE Y
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