Call Accounting Featured Article

A 'Survivable CDR' Solution to Save Call Data Records During Outages


February 07, 2019

If you worked in a contact center in “the olden days,” you might remember what a headache the process of call accounting was. In those days, companies using a phone switch like Avaya’s (News - Alert) had to download all call detail records (CDRs) in raw data via a 1,200 baud serial connection. The unlucky person responsible for creating meaningful reports from the CDR information spent most of his or her time wrangling this data.

Today, Avaya switches produce CDR data in a variety of formats and make it available to call accounting Solutions providers such as ISI Telemanagement Solutions and its Infortel Select product via IP links using what is known as Reliable Session Protocol. After receiving data, the solutions providers process the CDR records and generate meaningful reports tailored to the end users’ needs.

In a recent white paper, ISI’s (News - Alert) Director of Product Strategy, Mitchell Weiss, describes some of the challenges that have led to today’s intuitive call accounting solutions. In 2001, local spare processors (later called “local survivable processors,” or LSPs) were introduced to provide a backup for the call processing activities of Avaya S8700 or S8300 media servers which controlled one or more Avaya G700 media gateways.

If either the server or the communications link between the server and the gateway failed, the LSP could take over the call processing responsibility so the G700 media gateway could continue to serve its users. A few years later, the Enterprise Survivable Server (ESS) was launched with the goal of providing similar functionality for port networks controlled by Avaya S8500 or S8700 servers.

“The development of both the LSP and the ESS provided wonderful increases in overall system reliability and availability by allowing the pieces of a switch to continue to provide telephony service independently – even when the switch or its communication links experienced one or more failures causing the switch to no longer be capable of functioning as an integrated unit,” wrote Weiss.

In some cases, when there is a network or server failure or service interruption, call data records can be fragmented or lost because each LSP and/or ESS is required to generate CDR for the part of the switch that it controls. If the problem was due to the failure of an IP link, however, this backup communication can’t happen.

To get around this problem, ISI’s solution creates a sort of “buffer” in the form of a “Survivable CDR” to preserve the data for calls that occur while a gateway or port network is under the control of an LSP or ESS. This feature is available in ISI’s Communication Manager 4.0.

“When the survivable CDR feature is properly administered and if an LSP or ESS loses connectivity to the main, the switch will save its CDR on its local hard drive,” wrote Weiss. “Periodically, Infortel Select will log on to each of the Survivable CDR administered platforms and retrieve whatever CDR data files are available.”

In this way, companies aren’t losing valuable (and necessary, in legal compliance situations) call records to outages and glitches.




Edited by Maurice Nagle