3Com 3C10402B, Administrator'S Manual

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12
V
IRTUAL
C
ONNECTIONS
This chapter describes these elements of the system:
■
Overview of Virtual Tie Lines
■
TAPI Route Points
■
TAPI Settings
For more information about these topics and configuration procedures,
see the online Help.
Overview of
Virtual Tie Lines
A Virtual Tie Line (VTL) provides a way to make calls between system sites
that are separated geographically but tied together by a Wide Area
Network (WAN). VTLs are a licensed feature of the systems. V3000,
V3001R, and V5000 systems can support up to 48 simultaneous VTL
connections. NBX 100 systems can support up to 8 simultaneous VTL
connections
On any system, you can use a VTL connection either for an incoming VTL
call from any site or for an outgoing VTL call to any site. A VTL connection
is not dedicated in the same way as a physical tie line, which always
connects the same pair of sites. In the example in
Figure 20 , you can use
the VTLs on the Chicago system for any combination of incoming and
outgoing VTL calls to either Atlanta or Dallas.
The system can reroute VTL calls that fail to reach their destination on the
first attempt. For details, see
“Call Rerouting for Virtual Tie Lines” on
page 341 .
■
You must configure the system for either IP On-the-Fly or Standard IP
to use VTL connections to other systems.
■
VTL connections are not available on a SIP-mode system.