| 摘要 |
A switch enables a telephone to use one virtual circuit to connect through a packet switched network to any number of other telephones. The switch supports multiple network types, permitting, for example, the conversion of UDP and AAL5 data to AAL2 data. Multiple switches, each connected to several other switches by ATM virtual circuits, are used to form a telephone network. Each telephone connects to just one switch. When a telephone call is made, the call is sent to the associated switch, which then determines, based on destination, to where the call should be routed. The call is sent through the telephone network to the destination switch, which in turn sends the call down the one virtual circuit to the destination telephone. Header stripping using out-of-band signaling minimizes bandwidth wastage by not requiring the ingress and egress points of the packet-switched network to maintain a synchronized connection state that must be regularly validated and updated with state and error information.
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