TECHNOLOGY

MPLS

Control Plane

The HSX 6000 supports two signaling protocols: RSVP-TE and LDP. LDP is defined in RFC3036 and is used to distribute label bindings. The HSX 6000 distributes pseudowire labels, using LDP, as described in RFC 4447 (Pseudowire Setup and Maintenance Using the Label Distribution Protocol).

RSVP-TE is defined in RFC3209 and extends RSVP, as defined in RFC2205, to support the creation of traffic engineered LSP tunnels between MPLSenabled nodes across the IP/MPLS core. In the HSX 6000, RSVP LSP Transit is also supported as part of RFC3209. For an additional level of network resiliency, traffic engineered LSPs can be protected through the fast re-route mechanism, supported in the HSX 6000, which provides sub-second rerouting of LSPs away from network failures.

In the network scenario depicted below, the HSX 6000 systems are deployed as metro edge nodes that aggregate user traffic (attachment circuits) into RSVP tunnels. In this case, the carrier would connect all edge nodes with Gigabit Ethernet in a ring-topology. RSVP would be applied as primary-secondary (also known as RSVP Path Protection) for traffic protection. User traffic would traverse over multiple edge nodes before entering the core. This deployment type mirrors that found in SONET/SDH networks, where user traffic is aggregated into a ring at each hop. RSVP path protection operates in a way similar to APS.