secret of ATM's velocity.
header, which links a cell with a virtual channel on a physical link. The connection identifier
consists of two subfields: the Virtual Channel Identifier (VCI) and the Virtual Path Identifier
(VPI). VCIs and VPIs are used in multiplexing, demultiplexing, and switching a cell through
the network. They are assigned at each link between ATM nodes when a connection is
established, and they remain for the duration of the connection. ATM's flexibility allows it to
run on permanent virtual circuits (PVC), as well as switched virtual circuits (SVC).
an end-to-end circuit that can be rerouted in the event of failure. Cisco requires subinterfaces to
connect routers using PVCs. When configuring routers, note the VPI and the VCI number. Both
ends of the VPI and the VCI must match. Think of the VCI as a highway and the VPI as a lane
on that highway. For the sake of discussion, imagine a highway with five lanes (or paths). To
create the circuit, if Router 1 is using highway 1, lane 4, then Router 2 should use highway 1,
lane 4.
Same Highway--Different LaneNo Connection
Different Highway- Different LaneNo Connection
1 0 5