Making Sense of SIP Trunk Analysis
June 23, 2015
By Mae Kowalke
TMCnet Contributor
Traditionally, voice traffic architecture consisted of a wide variety of individual PBXs and key systems connected individually to the PSTN by a combination of T1 and POTS systems. As businesses move to SIP-based calling, however, this architecture is at once simplified by using all-digital systems and made more complex by having to connect desperate communication systems.
One of the primary engineering tasks now is properly accounting for the number of SIP lines needed, also known as “trunks.” If too many lines are in service, there is wasted infrastructure and its associated cost. Too few lines, and callers get busy signals and have anemic phone access.
Currently, many operators and businesses simply guess at how many SIP trunks they need. Usually, they err on the side of caution and greatly over-provision, adding unnecessary costs.
A better solution that is slowly finding adoption, however, is SIP trunk analysis.
For the proper engineering of networks at every phase of deployment, the number of concurrent trunks needed must be known. This calculation must be made both for on-net and PSTN calling.
With trunk analysis, the guesswork of having to select the right amount of SIP trunks is eliminated because actual usage patterns can be determined. A solution such as ISI (News - Alert) Telemanagement’s Infotel Select can how many actual concurrent calls are required at busy hours, how much existing traffic on the PSTN lines will go over the WAN and become on-net traffic, and how much actual Internet bandwidth will be required.
This is huge from an infrastructure planning perspective.
Having such information can help right-size the network and identify underutilized phone lines, as well as measure baseline utilization to determine performance before an infrastructure change. It can identify failed routing structures to locate opportunities to increase efficiency, and also forecast future growth needs to budget and plan network migrations.
SIP trunk analysis is a crucial component of proper call accounting, and it should not be overlooked in favor of off-handed guesswork.
Edited by Stefania Viscusi