Centralized VoIP: The Main Theme of Cost Savings
In our initial design in Figure 11.1, the solution is completely based on
a centralized platform. If we were to estimate the user volume of a
medium-sized corporation at 12,500 users at 10 sites, then the number
of servers required to handle this is 6 CallManagers, 10 Unity servers,
and 10 Microsoft Exchange servers for all voice mail needs. While this is
indeed a huge investment in technology and in people to maintain it,
your own decision to use VoIP must equally balance out the raw cost
savings plus the inherent savings.
The direct cost savings is a bit of a masquerade at first. You must
evaluate your current cost of local and long distance, PBX equipment
capital and recurring costs, as well as recurring circuit costs. Over time,
the organization should have a track record of the cost per user of a traditional
PBX system, which will be essential to making the cost comparisons
equal and honest.
Among those inherent savings is the ability to perform moves
/adds/changes in the blink of an eye without having to wait for the PBX
provider to come around and perform the tasks. With a moderately
trained administrative force, the time to complete these changes can be
reduced from days to minutes. The less obvious part of this is the ability
to schedule and host conference calls with little to no notice at all,
another benefit of the AVVID platform.
Designing & Planning…
412 Chapter 11 • Designing and Implementing Multisite Solutions
In the next section, you’ll learn how and why you should either take an
existing centralized CallManager and distribute it, or design a brand new distributed
solution. No matter which direction you take, the principles are the
same as that which you just learned, with a few twists.