Figure 6: Lsp Using Rsvp Path Set Up - Alcatel-Lucent 7950 SR User Configuration Manual

RSVP
SFO
10.10.10.1
SFO
10.10.10.1
Figure 6
(ILER 1) transmits an RSVP path message (path: 30.30.30.1) downstream to the egress label edge
router (ELER 4). The path message contains a label request object that requests intermediate LSRs
and the ELER to provide a label binding for this path.
In addition to the label request object, an RSVP PATH message can also contain a number of
optional objects:
•
•
•
Upon receiving a path message containing a label request object, the ELER transmits a RESV
message that contains a label object. The label object contains the label binding that the
downstream LSR communicates to its upstream neighbor. The RESV message is sent upstream
towards the ILER, in a direction opposite to that followed by the path message. Each LSR that
processes the RESV message carrying a label object uses the received label for outgoing traffic
associated with the specific LSP. When the RESV message arrives at the ingress LSR, the LSP is
established.
Page 40
PATH:30.30.30.1
1 2
RESV:10.10.10.1
label label
100|push 100|200|swap
1 2
100

Figure 6: LSP Using RSVP Path Set Up

displays an example of an LSP path set up using RSVP. The ingress label edge router
Explicit route object (ERO) — When the ERO is present, the RSVP path message is
forced to follow the path specified by the ERO (independent of the IGP shortest path).
Record route object (RRO) — Allows the ILER to receive a listing of the LSRs that the
LSP tunnel actually traverses.
A session attribute object controls the path set up priority, holding priority, and local-
rerouting features.
PATH:30.30.30.1 PATH:30.30.30.1
3
RESV:10.10.10.1
label
200|300|swap
3
200 300
7950 SR OS MPLS Configuration Guide
NYC
30.30.30.1
4
RESV:10.10.10.1 RESV:10.10.10.1
label
300|pop
NYC
30.30.30.1
4
OSSG016