This read-write value defines how the logical port's timeslots are used: structured mode carves out individual DS0s, unstructured mode allocates the entire line as one channel, strau supports only a single subrate DS0 timeslot (not supported on CESM-8T1/E1 or CESM-T3/E3), and framingOnVcDisconnect behaves like unstructured mode normally but loops line data back toward the line if the channel fails. An administrator selects framingOnVcDisconnect specifically when they want the physical line to maintain framing and loop data locally during a channel outage rather than going silent. For example, choosing structured(1) on an E1 port allows individually switching multiple DS0 timeslots as separate CES channels, whereas unstructured(2) would dedicate the entire E1's bandwidth to a single channel.