3Com NBX 100 Administrator's Manual - page 87
Overview of Virtual Tie Lines
87
A site code can be any number of digits, but typically, one- or two-digit
numbers make the most sense. The dial plan at each site must include
appropriate routing instructions for each of the possible site code.
Figure 11
shows three sites connected by VTLs. All sites use the same
range of extension numbers (1000 through 3999). To reach someone on
another NBX system, a user must dial a site code (61, 62, or 63 in this
example) followed by an extension.
Figure 11 Virtual Tie Lines Using Site Codes
To call someone in Atlanta, a user in Chicago must dial the site code 62
and then the appropriate extension (1000 through 3999). To reach a user
in Dallas, a user in Chicago must dial 63 and then the appropriate
extension (1000 through 3999). Because the extension is preceded by the
site code, there is no conflict between the extension dialed and an
identical extension number at the local site (Chicago). The choice of site
codes is made by the person who configures the dial plans for the sites.
See
“Dial Plan Configuration”
on
page 90
for more information on how
to set up VTLs in the dial plan.
Conference Calls
Using VTL
Connections
Users can set up conference calls over VTLs in much the same way that
they set up conference calls with other users at their local site, or at a site
reachable by an external telephone line.
WAN
Chicago
NBX System
Extensions
1000 – 3999
Atlanta
NBX System
Extensions
1000 – 3999
Dallas
NBX System
Extensions
1000–3999
Site Code 61
Site Code 63
Site Code 62