Time multiplexed processing of multiple SONET signals uses the same shared circuitry for framing, descrambling, maintenance signal processing, control byte processing and extraction, pointer tracking, retiming, and alarm indication. The structural members include a utility channel or C-shaped channels to which wire trays can be mounted. An operating system synchronization lock is acquired before the object is journaled to preserve the object from changes by the operating system, and held in place until after journaling has started. In one orientation, a port cover plate seals an opening that pierces a bulkhead, while a door panel rests horizontally on the operator environment side of the bulkhead.