If it Ain’t Broke…

Sometimes the best choice is to do nothing. This is true for life in general and it’s also true for SIP. While the big picture benefits of SIP are substantial, there are times when it’s not the best fit for your particular needs. This blog will explore a few of the most important areas where keeping things exactly as they are today is the right choice.

Feature functionality

Even though SIP has been around for well over a decade, its features are still not on par with the proprietary features offered by the digital, H.323, and sometimes even the analog sets from the big telephony vendors such as Avaya, Nortel, and Siemens. This is especially true when you get into the application space. For instance, you still cannot configure a SIP station as an Avaya contact center supervisor. Agent functionality was only recently added, but supervisors must still be digital or H.323. Also lacking from SIP phones are features for used for hospitality services and some military applications.

While not strictly a feature problem, the same holds true for those old analog alarm and elevator phones. They need to stay put until SIP can adequately replace them.


Although SIP phones have gotten significantly less expensive than they were a very short time ago, they are still not as cheap as a basic analog phone. This becomes very important in healthcare where some hospitals dispose of the room phone after every patient change. In fact, quite a few give the phone to the patient during the discharge process. Until a SIP phone can be bought for $5.00 or less, those old fashioned analog phones will still have a place in many hospitals.


Clearly, SIP requires an IP network and there are many enterprises where rewiring (cable, routers, switches) for SIP phones cannot be cost justified.

I’ve done some work for the nuclear industry and IP is not allowed in the reactor control rooms. Digital wiring will be there until the regulations are changed.

Basic Users and Usage

There are times when the power and flexibility of SIP aren’t required. For example, that phone hanging on the cafeteria wall doesn’t need presence, video, IM, or any of the other fancy stuff that SIP brings. If it ain’t broke, don’t fix it.

Trunk Requirements

You may have TDM features that cannot be ported to a carrier’s SIP trunks. An example might be a DNIS mapping service that is available on a carrier’s TDM trunks, but not their SIP trunks. In this case, moving to SIP trunks would break your call center’s ability to properly route calls. Also, many if not all service providers prohibit predicative dialers on their SIP trunks. Those annoying disturb-you-during-dinner devices need to stay on your existing TDM trunks.


There are probably more areas that I’ve missed, but the point is that SIP isn’t always the best choice. It’s certainly a excellent one for many users and call flows, but there are factors that may dictate that you keep things just as they are. However, pay attention to your evolving enterprise and SIP in general. Over time your needs may change and the restrictions that prevent you from moving to SIP will be lifted.


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