The TCB enables users to connect a tail circuit to a modem sharing device or to a modem that does not normally accommodate a DCE-type device connecting to it. Clock phasing differences are compensated for by buffering the data coming from the tail circuit into a 64-bit centered-ring buffer. This provides 32 bits of clock slippage in both the positive and negative directions. Clocking rates up to 64 kbps are possible while using the TCB.
Sync operation in both half-duplex and full-duplex modes is fully supported. Carrier detect signaling is used to re-center the ring buffers. All cabling crossover is done inside the TCB, so you can use standard straight-through cables for all inter-connections. The TCB is fully line powered. Just install it between the two modems and your tail circuit is ready to use.