| 摘要 |
<p>The ATM communication system (ATMK) has communication devices (K1, K2, K3) which are disposed in a ring line system (RS) formed from two ring lines (RING0, RING1) operated in opposite directions. Ring loops can be inserted via the communication devices to enable changeover, if required during the transmission of message cells, from an active path to an alternative path. The message cells are in each case prefixed in the respective communication device with an internal cell header which contains, inter alia, a path-individual serial number. In addition, the next expected or the last occurring serial number is retained on a path-individual basis in the respective communication device. When a ring loop is inserted or removed, using the serial number of the next incoming message cell of the respective path, the retained serial number concerned is updated as the message cell is forwarded. Subsequent message cells of the same path are forwarded only if the serial number which they in each case contain corresponds to the retained serial number. <IMAGE></p> |
