LSP ping, as described in RFC 4379, provides a mechanism to detect data plane failures in MPLS LSPs. For a specified FEC, LSP ping verifies whether the packet reaches the egress label edge router (eLER).
A 7705 SAR node using GNSS or IEEE 1588v2 PTP for time of day/phase recovery can perform LSP ping tests with high-accuracy timestamping.See the 7705 SAR Basic System Configuration Guide, "Node Timing", for information about node timing sources.