Monitoring quality of service (QOS) in a packet-based communication system and switching to a backup system in dependence on detected packet quality

摘要

A QOS protection system can switch between a current system and a reserved system depending upon degradation of packet quality. The QOS protection system in a redundant system includes detection means, for monitoring the packet flow and detecting at least the quality of degradation of the packet flow, and switching means for performing switching between the current system and the reserved system when the detection means detects degradation of quality. The checks carried out may include detecting loss of packet, packet error, packet delay, and variations between expected and actual packet arrival times. Time stamps and packet serial numbers may be used to help in the detection of these defects.