VoIP Test Solutions: Looking into the SIP Trunk

Feature Story

VoIP Test Solutions: Looking into the SIP Trunk

By Paula Bernier, Executive Editor, IP Communications Magazines  |  May 01, 2011

This article originally appeared in the May 2011 issue of INTERNET TELEPHONY.

IP communications has been a boon to business network managers far and wide. Not only does it enable them to put multiple traffic types on single connections, it can significantly lower their costs and enhance the functionality of employee communications themselves.

Of course, that’s not to say that these new networks don’t have their own challenges. Indeed, as a result of new converged networks and dynamic IP-based connections, network operators today more than ever need to make sure latency-sensitive traffic like VoIP is handled in way that ensures end users get the quality of experience they have come to expect as a result of their history using dedicated, nailed-up phone connections supported by legacy infrastructure.

So test and measurement companies are now delivering tools that enable network operators to get an end-to-end view into their networks and look at traffic at a more granular level so they can better manage the end user experience.

Testing SIP Trunks

Tone Software (News - Alert) Corp. is one such solution provider. The company earlier this year came out with SIP management through its ReliaTel VoIP QoS and Converged Infrastructure Management software.

This solution addresses the rapid adoption of SIP trunking in corporate telephony environments. Indeed, as Tone points out, SIP trunks can help businesses significantly lower their communications overhead, and SIP technology is becoming a foundation for deploying and implementing unified communications, mobility, collaboration and telepresence applications.

However, as Amit Kapoor, director of strategic technology advancement for Tone, notes, quality issues frequently originate at the SIP trunks, prior to the voice packets ever reaching the corporate gateways or switch. 

That’s why Tone has introduced the new solution, which includes four components: fault and management application; performance management; automation; and VoIP quality of service.

Kapoor tells INTERNET TELEPHONY that the fault and management application looks at such parameters as infrastructure availability, connectivity between devices, bandwidth, usage, memory, processor, alarming, traps, etc.

Performance management, meanwhile, provides information on what relevant performance metrics there are to a device. A PBX (News - Alert), for example, might have trunks, so it would look at trunk usage, capacity use; or, for a router, the solution would provide visibility about processing power, performance of links, etc.

The automation capability of the solution allows it to go beyond basic methods of data collection to automate troubleshooting.

With VoIP quality of service, the Tone solution dives into the service that’s traversing the infrastructure and offers statistics on it on an end-to-end basis. Those stats are about such parameters as packet loss, latency, jitter and other information.

Tone’s solution is unique in that it can work with network elements from any vendor, and it allows for segmentation of customers, meaning managed service providers can leverage this product to offer services, says Kapoor.

“Using ReliaTel SIP management, MSPs and enterprises have the visibility necessary to differentiate where these issues occur and the nature of the quality impairment – which significantly increases their ability to rapidly resolve quality issues and control VoIP quality and service levels,” he says.

More on SIP Trunking

Irwin Lazar, vice president of communications and collaboration research at

Nemertes Research, last year said that about 55 percent of companies are either deploying or evaluating SIP trunking.

The reason for the business world’s interest in SIP trunking is clear: The service is far less expensive than buying PRI lines for voice traffic.

“There hasn’t been a compelling business case for SIP in the enterprise for anything other than interconnection of PBXs,” says Lazar. “Most of the companies we talk to who are doing trunking internally are doing it to save long-distance costs.”

As Rick Pfleger, director of sales engineering at managed service provider VoIP Logic (News - Alert), recently told INTERNET TELEPHONY, an average mid-sized company typically uses a T1 for data and a PRI for PBX voice communications. But moving to SIP trunking can enable the company to get rid of the PRI or PRIs and instead put all of its traffic over a single connection, potentially a bonded copper or fiber-based Ethernet link.

Lazar of Nemertes Research said SIP trunking can produce 20 to 60 percent in savings for a company.

SIP trunking also has some other nice features, says Lazar, adding that companies can leverage the technology to route calls based on time of day or on load and to set up virtual numbers in remote parts of the world.

Edited by Stefania Viscusi


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