Melissa Swartz
Melissa guides enterprise business clients through the complex process of finding the right communications solutions for their business, and getting...
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Melissa Swartz | January 20, 2016 |


SIP Trunking: Not a Simple Replacement

SIP Trunking: Not a Simple Replacement There are many variables to consider when moving to SIP trunks, from features and capabilities to pricing and facility requirements.

There are many variables to consider when moving to SIP trunks, from features and capabilities to pricing and facility requirements.


If you haven't already moved to SIP trunks, chances are you've been told by various sales teams that you are missing out on savings, flexibility, or possibly even the future. There's no doubt that most carriers are encouraging customers to get off of analog and digital services (if you can call massive rate increases "encouragement"). AT&T has announced its 2020 goal to virtualize and control over 75% of its network using a new software-centric network architecture. So if you don't have it already, SIP is likely in your future.

However, a move to SIP trunking is more than a simple replacement of current digital or analog services. Why? Because almost everything changes.

The pricing structure is different, for example. Many carriers charge a fixed fee per month for each concurrent call path, but not all of them do so. Numerous carriers charge for local calls that may have been free prior to the move to SIP. How many local calls does your organization make per month? Most people don't track this information, which makes it difficult to project what your new costs will be for this element. Some carriers include a block of free minutes in their offer (sometimes local, sometimes long distance minutes). Without knowing your local usage, there's no way to know if there are enough minutes to keep the local calls "free."

Other surprise costs can include:

  • Per call charges for 911 calls (as much as $75 per call)
  • Monthly charges for 911 service (usually per DID number)
  • Charges for an excessive number of short calls (as defined in the contract)

Typically, these types of charges are not pointed out during the sales process; you only learn about them when you read the contract in detail (or see them show up on the bill).

One of the benefits of SIP trunking is that it's usually easier to build in resiliency by having SIP trunks at two or more locations, as illustrated below, with the ability to move traffic to other sites if needed. For this example, let's say that Location A is the primary site, which will receive 100% of the SIP traffic under normal circumstances. Location B is the failover site. This is an area where there are big differences in carrier offerings.


Some carriers charge monthly for both sets (a total of 200) of call paths, while others only charge for one set (100 call paths) until the call paths at Location B are put into use. Still, other carriers will allow you to burst above the "normal" number of call paths and pay for the additional capacity only when it's used.

Obviously, this makes a big difference in your monthly costs.

Other differences in SIP offerings include:

  • Underlying facility requirements
  • Configuration and features
  • Failover and number re-routing capabilities

There are many variables to consider when moving to SIP trunks. It is important to understand both your requirements and the capabilities of various providers. It is also important to seek out the costs that may be hidden in an agreement. You need all of this information to make the best decision for your business's unique situation.

To learn more about this, come to my Enterprise Connect session, "Top 4 Pitfalls to Avoid When Implementing SIP Trunking," in which I'll be speaking about the pitfalls and discussing them with a panel of experts.

Learn more about SIP and SIP trunking at Enterprise Connect 2016, March 7 to 10, in Orlando, Fla. View the SIP/SIP Trunking track sessions; register now using the code NJPOST to receive $200 off the current conference price.

"SCTC Perspectives" is written by members of the Society of Communications Technology Consultants, an international organization of independent information and communications technology professionals serving clients in all business sectors and government worldwide.

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