Call Accounting and Billing Solutions
TMSs or Telephone Management Systems are an integral part of any telephony
network, and irregardless of whether you’re using a traditional telephony solution
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AVVID Applications • Chapter 7 209
or an IP telephony solution, the guidelines stay the same.When implementing a
call accounting or billing solution within an IP telephony environment, the same
values you would look for in a TMS when used in a traditional solution will be
applicable in an IP telephony solution. Next, we’ll discuss some of the factors to
take into account when looking to implement a call accounting and/or billing
solution.
In an IP solution, the idea of call accounting and billing is based on a Call
Detail Record (CDR), which, as the acronym suggests, is a detailed record of a
call. Currently, the Cisco CallManager has the ability to provide CDRs, which
can be created on certain Cisco VoIP gateways. Used in conjunction with the
solution mentioned earlier, we can achieve both call accounting on a local and
global scale. Before getting into any guidelines regarding the implementation of
these applications, it might be best to give you an idea of the information contained
within both the Cisco CallManager CDRs and the VoIP gateway CDRs.
The Cisco CallManager, as mentioned previously, is a Windows 2000 Server,
that comes with SQL Server as well as the relevant service packs installed. Using
SQL, the Cisco CallManager has two databases that store information with
regards to a call:
CallDetailRecord This database collects call-specific information.
CallDetailRecord Diagnostic This database contains values which are
used in conjunction with applications to determine the quality of the
call commonly known as a Call Management Record (CMR).
NOTE
There may be multiple entries in the CallDetailRecord Diagnostic
Database that relate to a single entry within the CallDetailRecord
Database due to certain factors such as quality changes, and so forth.
For a call accounting/billing application to pull data from a Cisco
CallManager or CallManager cluster, CDRs first need to be enabled.This is
achieved by launching the CallManager Administration tool from within a Web
browser and changing the values of the following two parameters, both of which
are disabled by default. If you have multiple CallManagers within a cluster, make
sure both parameters are changed on all the CallManagers, otherwise no CDRs
will be available (see Figure 7.3).