Essay on Relationship Between Mpls And Ipv6
The main differences from the IPv6 source route model are:
• The source route does not involve IP addresses; instead, the source route is encoded as an ordered list of segments.
• A segment can represent any instruction; either a service or a topology path. The path to an IP address is usually the shortest-path to that addess. A segment on the other hand can represent any path. (e.g. an adjacency segment can force a packet to a next-hop via a specific adjacency even if the shortest path does not use that adjacency).
• The edge routers (ingress and egress) are identified and are always available, thus permitting accounting and policy applications.
• The functionality of the source route cannot be controlled from outside the domain of the Segment routing.
The main differences from the current MPLS model are:
• Globally indexed segments like IGP prefix segments are introduced for Segment Routing.
• MPLS signalling protocols like LDP and RSVP are not required for SR. Even if they are present, SR can co-exist and work in co-relation with RSVP and LDP.
• Unlike RSVP-based explicit routes where midpoints of the tunnels maintain states, SR-based explicit routes only require per-flow states at the ingress edge router. The traffic engineer policy is applied at the ingress edge router.
MPLS Instantiation of Segment Routing
While applying SR to MPLS, the 20 right-most bits of the segment are encoded as a label. This means that, in the MPLS…