3Com NBX 100 Administrator's Manual - page 86
86
C
HAPTER
2: D
IAL
P
LAN
Assess your growth plans for each site to verify that as you add
telephones you do not exceed your defined extension ranges.
Figure 10
depicts a configuration that uses unique extension ranges
Figure 10 Multi-site Network using Virtual Tie Lines
In the sample network shown in
Figure 10
, each site is set up to use a
unique range of telephone extensions. The dial plan on each of the
systems is configured so that whenever a call is made to an extension not
located at the local site, the NBX system sets up a VTL connection to the
appropriate site.
To make a call to a user in Dallas, a user in Chicago dials a Dallas
extension (3000 through 3999). The dial plan on the Chicago NBX system
is configured to set up the necessary VTL connection to the Dallas NBX
system, and then to the extension at that site.
See
“Dial Plan Configuration”
on
page 90
for further information on
how to set up VTLs in the dial plan.
VTL Connections
Using Site Codes
The simpler way to implement VTL connections uses a site code,
consisting of one or more digits that a user must dial to specify the site
that is being called. This approach requires no restriction on the
telephone extension ranges, but does require the caller to dial the site
code digits as well as the extension.
WAN
Chicago
NBX System
Extensions
1000 – 1999
Atlanta
NBX System
Extensions
2000 – 2999
Dallas
NBX System
Extensions
3000 – 3999