Eicon Networks 1550 - Manual (Page 105)

Web Interface Settings Glossary 105
Protocol Menu (VHSI Tree) > Virtual Circuits Group
(X.25)
These parameters are only available when the protocol is set to X.25.
PVC - Permanent Virtual Circuits
Defines settings for PVCs (Permanent Virtual Circuits). A PVC is permanently
established between two destinations. No call setup is required.
IVC - Incoming Virtual Circuits
Defines settings for IVCs (Incoming Virtual Circuits). An IVC can only receive calls.
TVC - Two-way Virtual Circuits
Defines the settings for TVCs (Two-way Virtual Circuits). A TVC can both make and
receive calls.
OVC - Outgoing Virtual Circuits
Defines the settings for OVCs (Outgoing-only Virtual Circuits). An OVC can only issue
calls and not receive them.
Sequential Assignment of VCs
Enables/disables sequential assignment of virtual circuits. Most X.25 networks assign
virtual circuits sequentially. However, some networks, such as British Telecom's Packet
Switch Stream, assign virtual circuits non-sequentially using Logical Channel Group
numbers. If this is the case, you must define the starting LCN (Logical Channel
Number) for each group of virtual circuits (PVC, IVC, TVO, and OVC).
Default: Enabled.