The invention provides an optical burst switch in an Optical Burst Switched (OBS) communication network, said optical burst switch comprising means for monitoring and maintaining mesh of virtual optical paths from a communication node to a plurality of other communication nodes, arranged in a ring network, enabling traffic data to be transmitted and/or received between nodes via a physical optical path. The switch also provides means for sending a data packet probe on a virtual path from a node to each other node in the OBS communication network, wherein data packet probe information received at said switch provides information of availability of the physical optical path for sending traffic data between nodes. The switch can be configured such that the rate at which this path monitoring is scheduled guaranteeing less than 50ms protection switch in the event of monitoring a failed or degraded path.