Nokia 7705 SAR-W Series - Figure 13 SR-TE LSP Label Stack Programming

MPLS and RSVP-TE
116
MPLS Guide
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The link-protect LFA backup next hop for an adjacency SID can be programmed at
the ingress LER and LSR nodes (as explained in SR-TE LSP Protection).
A maximum of 12 labels, including all transport (including entropy), service, NGE,
and OAM labels, can be pushed. The label stack size for the SR-TE LSP can be 1 to
11 labels, with a default value of 6.
The label stack size manipulation includes the following LER and LSR roles:
• LER role:
- push up to 12 labels depending on the service type
- pop up to 8 labels
• LSR role:
- pop up to 5 labels and swap 1 label for a total of 6 labels
- LSR hash of a packet with up to 10 labels
An example of the label stack pushed by the ingress LER and by an LSR acting as
a PLR is illustrated in Figure 13.
Figure 13 SR-TE LSP Label Stack Programming
On node A, the user configures an SR-TE LSP to node D with a list of explicit strict
hops mapping to the adjacency SID of links A-B, B-C, and C-D.
60
90
70
100
80
A
Node SID=50
B
Node SID=60
D
Node SID=80
C
Node SID=70
E
Node SID=90
F
Node SID=100
27873
PKT
SVC-LBL (X)
BGP-LBL (D)
CD-SID=1002
BC-SID=1001
1000
10
10
Adj-SID:
IGP Metric:
TE Metric:
3000
10
10
Adj-SID:
IGP Metric:
TE Metric:
1001
100
10
Adj-SID:
IGP Metric:
TE Metric:
2000
10
10
Adj-SID:
IGP Metric:
TE Metric:
2001
10
10
Adj-SID:
IGP Metric:
TE Metric:
1002
100
10
Adj-SID:
IGP Metric:
TE Metric:
PKT
SVC-LBL (X)
BGP-LBL (D)
CD-SID=1002
C-SID=70
3001
10
10
Adj-SID:
IGP Metric:
TE Metric:
PKT
SVC-LBL (X)
BGP-LBL (D)
CD-SID=1002
PKT
SVC-LBL (X)
BGP-LBL (D)
PKT
SVC-LBL (X)
BGP-LBL (D)
CD-SID=1002
C-SID=70