A long setup required by this connection must be compensated by relatively long call hold time . Therefor circuit mode is not suited for data calls . Packet Mode Packet mode is for data communications which are featured by bursty traffic . Physical channels are not dedicated to a specific end to end connection and they may be shared by many end to end logical connections . Packet switching is suitable for delay insensitive traffic .
Packet is a subdivided unit of transmission data.
The receiver is responsible for reassembling the original message from incoming packets . The logical path through which the packet is switched, is fixed by different addresses that the network recognizes. Packets are sent to a network node by the user host and then they are forwarded through the network from node to node until they are delivered to the dest ination noed . The communication is approached through a Virtual Circuit . There are many services available on ISDN and they require different bearer services and switching facilities.