Sets the duration, in milliseconds, of the T331 signaling timer on this port, defaulting to 60000 ms; this is the ITU-T Q.2931 timer used in add-party procedures for point-to-multipoint calls, bounding how long the network waits for a response before retrying, per ITU-T Q.2931. Admins normally leave signaling timers at their standard defaults, adjusting them only to interoperate with a far-end switch that uses nonstandard timer values or to work around a specific signaling interoperability issue.