327
Intra-domain multi-segment PW
An intra-domain multi-segment PW has concatenated PWs within an AS. You can create an intra-domain
multi-segment PW between two PEs that have no public tunnel to each other.
As shown in
, there is no public tunnel between PE 1 and PE 4. There is a public tunnel between
PE 1 and PE 2 and a public tunnel between PE 2 and PE 4. To create an intra-domain multi-segment PW
between PE 1 and PE 4, you can perform the following operations:
1.
Create a PW between PE 1 and PE 2 (PW 1) and a PW between PE 2 and PE 4 (PW 2).
2.
Concatenate the two PWs on PE 2.
Intra-domain multi-segment PWs can fully use existing public tunnels to reduce end-to-end public tunnels.
Figure 85
Intra-domain multi-segment PW
Inter-domain multi-segment PW
An inter-domain multi-segment PW has concatenated PWs in different ASs, and is a method for inter-AS
option B networking.
As shown in
, to create an inter-domain multi-segment PW between PE 1 and PE 2 in different
ASs, you can perform the following operations:
•
Concatenate PW 1 and PW 2 on ASBR 1
•
Concatenate PW 2 and PW 3 on ASBR 2.
CE 1
PE 4
PE 1
PE 2
CE 2
MPLS or IP backbone
PE 3
Tunnel
Tu
nn
el
PW 1
PW 2
PW