Abstract: A protocol for intra-shelf exchange of SONET/SDH line and path alarm, and section and line digital cross-connect information is disclosed. The protocol encompasses a method including continual monitoring each SONET/SDH datapath channel for alarms by one or more line cards (e.g., optical line interface, electrical line interface), processing the results of the channel monitoring to consolidate and encapsulate SONET/SDH alarm data by the line cards, forwarding this data to a switch card, which makes switching decisions based on the data. The SONET/SDH line, path, and equipment fault information may be collected, filtered, and prioritized by the line cards with some knowledge of the protection scheme(s) being implemented by the switch card, and may be formatted into an efficient encoding of the quality of each path.