RSVP Tunneling

An RSVP tunnel sends traffic from an ingress node through an LSP. The traffic that flows through the LSP is opaque (or tunneled) to the intermediate nodes along the path. Traffic flowing through the tunnel to an intermediate node along the path is identified by the previous hop and is forwarded, based on the label value(s), to the downstream node.

RSVP-TE can:
  • Establish tunnels with or without QoS requirements.
  • Dynamically reroute an established tunnel.
  • Observe the actual route traversed by a tunnel.
  • Identify and diagnose tunnels.
  • Use administrative policy control to preempt an established tunnel.
  • Perform downstream-on-demand label allocation, distribution, and binding.

Some LSRs require their neighboring LSRs to include their Router ID in the Extended Tunnel ID field when sending RSVP-TE messages. The Extended Tunnel ID is a globally unique identifier present in the RSVP common header Session object (see RFC 3209). To provide maximum compatibility with other vendors‘ implementations, the ExtremeXOS MPLS implementation accepts RSVP-TE messages regardless of the Extended Tunnel ID value and always inserts the local Router ID into the Extended Tunnel ID field prior to transmission of an RSVP-TE message.