RSVP-TE Convergance

This feature introduces RSVP Traffic Engineering (TE) protocol extensions to support Refresh-interval Independent RSVP (RI-RSVP) defined in RFC 8370 for fast reroute (FRR) facility protection to allow greater scalability of label-switched paths (LSPs), faster convergence times, and decreased RSVP signaling message overhead from periodic refreshes. On Juniper devices, RSVP-TE runs in enhanced FRR mode, also known as RI-RSVP mode, by default, which includes protocol extensions to support RI-RSVP for FRR facility bypass originally specified in RFC 4090. The implemented RI-RSVP protocol extensions are fully backward compatible. In mixed environments, where a subset of LSPs traverse nodes that do not include this feature, RSVP-TE running in enhanced FRR mode automatically turns off the new protocol extensions in its signaling exchanges with nodes that do not support the new extensions. As part of enhanced FRR profile, several changes were made and new defaults adopted. These are listed here. 

• RSVP-TE runs "enhanced" FRR, or RI-RSVP mode, by default, which includes enhancements to facilitate scaled-up scenarios. You can disable these new protocol extensions on a router with the no-enhanced-frr-bypass command. 
• RSVP refresh reduction extensions defined in RFC 2961 are enabled by default. You can disable them with the no-reliable command. 
• The default value for keep-multiplier, which is 3, is applied to the new default refresh time. 
•  Local reversion is disabled by default. The existing CLI configuration for node Hellos, [edit protocols rsvp node-hello], is still available but the action is redundant. If enabled, a message is displayed to indicate that the configuration is not necessary in conjunction with enhanced FRR.