May 8, 2012

SIP Trunking: All You Can Eat or A la Carte?

Many of today’s savvy enterprise decision makers are constantly looking to improve their communications infrastructure with Session Initiation Protocol or SIP trunking.

One of the decisions facing them is whether or not they should drive their service providers to a flat-rate pricing model or a usage-based one.

The flat-rate model for SIP trunking offers a single session price that includes local and long-distance voice, data and a myriad of capabilities including failover. The advantage with buying an “all-you-can-eat” session is that enterprises can lock in pricing and know that they have a fixed-cost. On the downside, companies might be over-paying for services they don’t use or the session price might not include QUITE everything.

The usage-based pricing model typically costs a little more, but you only pay for what you use.

Determining the cost of ownership, however, with the usage-based model is not as simple as the flat-rate model. Then there are concerns about data usage, failover and E-911.

What is a savvy decision maker to do? The answer depends on a number of variables.

How do you plan to optimize your network?  Before SIP trunking, enterprises had to work with more than one local carrier to provide separate Primary Rate Interface (PRI) lines or IP connections to each location. Now, enterprises can procure SIP trunking and share high-capacity SIP trunking to one or more primary locations thereby eliminating lines and equipment, gaining business continuity options and sharing capacity for sessions across enterprise. The question is – what’s included in the session? Some carriers include everything and others make you buy add-ons. Here are some important questions to ask your carrier?

Can I share sessions?

By using SIP trunking, you can simplify how voice services are bought and used across the enterprise. But make sure your carrier allows you to share sessions between the branch locations.  If they do, you will be able to streamline local services, and improve your communications infrastructure by eliminating equipment, software and other operating expenses.  If they don’t, they are just repackaging legacy services and while the session price might be lower, you don’t gain the other efficiencies.

Do I need to buy sessions for failover?

Many carriers will also make you buy sessions you don’t need for failover. You already pay for the sessions you need on a regular basis, why should you pay for failover sessions? If the ones you pay for monthly are not available, carriers shouldn’t charge you extra when they don’t work. Believe it or not some do. Carriers really need to make sure the loop and port are sized correctly, not charge you for extra sessions you hope you never use.

Is local included in the session?

Another important consideration is how the carriers rate local calls. Typically, any call that hits the SIP trunk is going to the PSTN, but how they bill you will vary greatly. Some will rate the call by originating BRANCH location and terminating location so the call will be considered local. Others will rate ANY call that traverses the PSTN as Long Distance and you’ll have to eat those costs – even if they say you are getting the LD as part of the session.

How does the carrier support E-911?

Some Carriers deliver E911 info to PSAP as part of the session. Others will require that you procure additional trunking for this.  This is an important consideration if you plan on originating calls from remote branch locations and using the SIP trunks for deliver and receive calls. If you are not careful, you’ll end up having to buy additional Business Lines or PRI’s for E-911 and local traffic – exactly what you were trying to avoid.

Can I share access with both and data?

A third important consideration is whether or not Service Providers allow Data to share the ESIP access or require you to procure separate access. Some will even allow you to share access, but then charge you per Megabyte for data. If they do, make sure that they allow both signaling and media  to go through the location where they terminate the SIP trunk. This way the signaling can flow through the main location where you have your SIP trunk and the media can flow directly between a branch site and the carriers network, saving bandwidth on your MPLS Network and avoiding even greater costs.

Everyone’s challenged to do more with less, and SIP trunking allows the enterprise to take advantage of the technologies that are being developed today and if deployed effectively the enterprise gains efficiencies by:

  1. Reduce Total Cost of Ownership (TCO) with less equipment to buy and manage at every location
  2. Control costs by sharing capacity for voice sessions across network
  3. Adding Redundancy and Failover from one Enterprise SIP connection to another
  4. Simplifying and consolidate local and long distance inbound and outbound calling across enterprise, regardless of physical location
  5. And managing BETTER!

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