terface provides continuous works to date. The use of a common packet format for transport of savings on line costs by offering more efficient management of all network traffic, results in simple packet routing and multiplex- bandwidth. Idle data is not transmitted over the network as it is with TDM platforms. Bandwidth is instantaneously used for All packets are of the same length, use the same number of address bursts of data when necessary, and is then instantaneously freed bits, and are transported through the network using common switch- for usage by other traffic. Bursts from multiple sources are ing, queuing, and transmission techniques, no matter what the interleaved on the same available bandwidth. connection type or its bandwidth requirements. Other than control Cell Relay 55/7 Cell Relay Switch Cell Relay Switch Input Trunk Trunk Adaptation Interfaces Input Interfaces Adaptation Trunk Frame Frame Flags Free Bandwidth Trunk Utilization Speech Speech Silence Voice Cells Cells are generated only for active Bandwidth instantaneously allocated speech or data frames. only to active voice and data channels. No cells are generated for silence Bandwidth utilized twice as efficiently or data flags. as a circuit switch. Figure 55.6 Cell Relay switch information, the only real differences between packets are content Hybrid switching attempts to provide both circuit and packet and destination. Packets or cells are only generated on the trunk switching features by dividing the slots on a TDM frame between when actual information is present, therefore genuine bandwidth on voice channels and data channels. Since the voice slots are time demand is provided. division multiplexed, and the data slots are packet switched, voice Comparing TDMs and packet switching with Cell Relay, the main and data traffic must be separated to different sections of the switch. benefits of traditional packet switching networks are lower costs, With the simplest scheme, the voice/data boundary and frame due to statistical multiplexing techniq