This annex specifies methods that can be used by H.323 entities to implement robustness or tolerance to a specified set of faults. Methods for recovery of call signalling (ITU-T H.225.0) and call control signalling (ITU-T H.245) channels are specified. RAS (ITU-T H.225.0) does not involve a connection and recovery, involving registering with an alternate gatekeeper, is covered elsewhere and so not specified in this annex. Recovery of Annex G service relationships is for further study.