The Newly Merged VoIP Network
Internet
Router
3524 Switch
Network
Printer
Server
IP Phone Server
Connecting the Site to External Telephony Systems
Thus far, we’ve talked about the LAN environment and its structure when used to
support VoIP and AVVID solutions as a whole.To make this a complete solution,
the LAN VoIP users must be able to connect to the outside world. In traditional
PBX systems, the usage of a PRI provides up to 23 channels of 64 Kbps across a
standard four-wire communications circuit.This PRI, depending upon the location
in the country, can cost from $20 to $60 per single 64 Kbps channel. Even at
its cheapest, such connectivity adds a monthly recurring cost of $400 to the solution,
not counting long distance charges. However, you might find pricing for a
PRI different from these figures, which are well established in the southeastern
United States.These figures are provided merely as a reference point.
Since the site will pay long distance charges regardless of the solution,
whether it be VoIP or a traditional PBX system, this charge can be ignored when
considering the Return On Investment (ROI).There is, however, a cheaper solution
for small sites without having to use a PRI circuit. Most small Cisco routers
support the usage of the network module voice slot in either the one- or twoslot
design, the NM-1V and NM-2V. Each slot can accommodate one of the following
three modules: