User Guide

Virtual channels
VCs and the STPro
Channel identifiers
13 Networking - ATM
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3EC 36231 ABAA TCZZA Ed. 01
13.1.1 ATM Parameters
ATM uses VCs to create individual communication links between
network nodes. ATM uses two types of VCs:
 Permanent Virtual Channels (PVCs) are static connections
between network nodes that are configured statically. For a
Permanent Virtual Channel (PVC) the nodes of the connection
operate as if they are connected with a dedicated physical
line.
 Switched Virtual Channels (SVCs) are similar to voice
telephone network connections. These are temporary
connections between any two end points on the network and
are configured via signaling. A Switched Virtual
Channel (SVC) is created dynamically for each session and
released when the information exchange is complete.
Currently all STPro ATM connections are static, i.e. of type PVC.
Each ATM cell carries two labels called Virtual Path Identifier (VPI)
and Virtual Channel Identifier (VCI) as part of its header.
An ATM channel, commonly referred to as Virtual Channel,
is fully identified by these two labels. Therefore, multiple ATM
channels can reside on your DSL line.