SVC is one of two types of #Virtual Circuit that provides temporary connection. It is typically used for irregular data transfer between data terminal equipments (DTE) across #the network. It has 4 operational states: Call Setup, Data Transfer, Idle and Call Termination.
If SVC is Idle for some predetermined amount of time, it will automatically terminate itself. A call is required if there is in need of data flow. Thus, it often produced undesired overhead when compare to its counterpart.
PVC is, like the name suggested, a permanent connection within #packet-switched network that is set up and configured manually. Since it is running at all times, there’s no need to call setups or termination. Therefore, compare to Switched Virtual Circuit (SVC), it has only 2 operational states: Data Transfer and Idle. Typically, it is installed for direct connections between sites.
There are two kinds of circuits primary used by ATM: Permanent Virtual Circuit (PVC)# and Switched Virtual Circuit (SVC)# . The latter is quite common among ATM installation. ATM also utilises the LAN Emulation (LANE)# technology, which offer user the ability to communicate using Local-Area Network (LAN) protocols within the ATM network.