TMCnet - World's Largest Communications and Technology Community



tmc logo
November 2009 | Volume 12 / Number 11
On RAD’s Radar

Interop is the Key to SIP Sales

“No trade association in IP communications is working harder to develop standards for relevant technologies than the SIP Forum,” according to a TMC (News - Alert) blog post. Why is this important? Because SIP isn’t a standard like ISDN-PRI is. PRI is a plug-and-play standard that works with almost every PBX (News - Alert) and phone system in existence.

With everyone turning to SIP trunking as the new PRI replacement technology, the largest hurdle is whether the SIP provider can deliver a SIP trunk that will work correctly with the customer PBX or phone system.

SIP trunk is not yet a standard; it is a specification of about 30 RFCs, as Cbeyond (News - Alert) puts it, “Cbeyond and this (SIP Forum) team formed a working group which authored an overall specification for SIP trunking. As a result of this collaboration, customers may interconnect leading IP PBXs and Cbeyond’s BeyondVoice through a recognized standard-based approach to SIP trunking services.”

“Compliance with the SIPconnect specification helps to reduce the time and resources required to achieve interoperability between an IP PBX manufacturer and a service provider. Furthermore, it helps minimize the time and effort required for an IP PBX reseller to install and maintain the solution.”

SIP providers announce interoperability tests regularly, but you should notice that it usually is very specific – for example, “certified with Toshiba (News - Alert)’s family of Strata CIX IP business communication systems.” Likely, that means your customer better have a Strata CIX IP system with an IP card or it may not work right.

Most of the work is done from the softswitch. So in the case of BroadSoft (News - Alert), once it certifies a brand or model of PBX, all 300-plus of its customers are able to interop with it.

As an agent, when you are proposing a SIP trunk solution, be certain that the customer’s PBX has been certified as interoperable with the SIP carrier. A work-around is to add a box at the customer premises that will convert the SIP trunk to PRI signaling. But you will lose some of the SIP features that helped you differentiate your service from a telco PRI. IT

Peter Radizeski is head of telecom consulting agency RAD-INFO (News - Alert) Inc. (

» Internet Telephony Magazine Table of Contents

Today @ TMC
Upcoming Events
ITEXPO West 2012
October 2- 5, 2012
The Austin Convention Center
Austin, Texas
The World's Premier Managed Services and Cloud Computing Event
Click for Dates and Locations
Mobility Tech Conference & Expo
October 3- 5, 2012
The Austin Convention Center
Austin, Texas
Cloud Communications Summit
October 3- 5, 2012
The Austin Convention Center
Austin, Texas