Why we don't recommend Internet based Telephony services
Posted by rbTech Staff, Last modified by rbTech Staff on 27 January 2014 12:17 PM

Internet based phone service, also known as SIP trunking or Cloud based PBX service, is very popular right now.  At rbTech, we have a wealth of experience with both cloud based PBX products and SIP 'trunking' services.  Customers call us daily asking about the various iterations of the terms above, and our answer is the same in every instance.

In brief, we only recommend telephony service where you have a direct, contractual relationship with the party that delivers the service on your premises, and (and this is critical) there are no third parties in the delivery path that don't have a contractual relationship with you, or the company that provides the service to you.

Services that make the cut above in our service area:
T-1/ ISDN/ PRI service from FairPoint, Sovernet, Comcast, Waitsfield and Champlain Valley Telecom, or TDS.
Analog (or POTS, Plain Old Telephony Services) lines from the same companies.
SIP services that do not rely on the public Internet for service delivery (again, almost certainly delivered by one of the above companies).

Services that don't make the cut:
SIP or IP Voice services from any company that relies on the public internet for delivery of service - RingCentral, DSCI, SimpleSignal, BroadVOX.
Any service that has a 'hole' in the delivery path where service availability and quality is not guaranteed by the company delivering the service.

We make this recommendation based on several factors and a LOT of experience troubleshooting Internet based telephony services.

One factor to keep in mind is that while these services often appear much less expensive, they *always* result in much higher support costs, as you are constantly in the position of needing to prove to your telephony provider that your equipment isn't to blame.  Often the testing is time intensive and highly technical, resulting in costly service calls to your friendly PBX vendor.  This is a bad situation for everyone:  We don't like performing this work any more than you like paying for it because we know what the outcome is going to be, but we still have to prove it out each and every time.

Internet based phone service, whether SIP trunks or (even worse) Internet based Virtual PBX services, have an achilles heel:  The service is not guaranteed, and you have no contractual stick to weild if the Internet gets slow between you and the provider's physical location.  The Service Level Agreements all have a common stipulation - they guarantee that their service is available, but they do NOT guarantee that you will be able to reach their service, or even use it.

Take this example:  Your network -> Cable modem -> Internet -> VOIP provider
In this example, if your internet connection is slow, or there's congestion at some point between your cable modem and the VOIP provider's physical location, you will experience degraded call quality and/ or dropped calls, and there is nothing you can do about it.  The VOIP provider is doing exactly what they're responsible for, and you don't have a contract with them, or your ISP, that guarantees that your voice traffic will get through.

From our perspective, this is an unacceptable level of risk, with an unacceptable chain of responsibility.  In our experience what happens in this instance is that the VOIP provider points the finger of blame at the ISP, and the ISP (correctly, and fairly) says that they can't guarantee that there's sufficient bandwidth available for the calls to get through.  Often the slowdown is in a 3rd party's network (that your traffic must traverse to get to the VOIP provider) and is outside of both your ISP's network or that of your VOIP provider.

There are some virtual PBX services that are provided by a company that has physical presence in your building:  FairPoint, Waitsfield and Champlain Valley Telecom, and Comcast offer similar services in this regard.  The key difference with these services is that there are no intermediary parties in the mix should you have dropped calls or voice quality issues.  And you have a contract with the provider of the services should things go wrong, and there's no way for them to duck responsibility for making it work right.

We used Internet based SIP service here for a time, and we have a dozen or so clients who used either Internet based Virtual PBX or SIP services in the past.  At this point in time we have only 3 who still use it, and of those 3, only one is reasonably happy (with some occasional grumbles about dropped calls or crummy voice quality).  We used SIP service from 2 different, geographically separate providers, over the course of 3 years.  With the first provider, service was great for a brief time, then progressively descended to unacceptably terrible over a period of a year or so.  We then changed to a second provider (no other changes made to either our Internet service, PBX or any other equipment).  The service was much better (though I wouldn't way great) for a few months, and then descended again to simply unacceptable (choppy or unintelligble calls at least once per day).

At that point, we had been transitioning our clients away from Internet based telephony service to either PRI or analog service, and we made the switch ourselves to a proper, channelized PRI service.  We haven't had a dropped or garbled call since we made that change.  Again, no other changes were made to our PBX, or phones or anything else.  The only change we made was to the service that fed the PBX here.  Our experience with our client sites has been a perfect mirro of our own:  continual complaints about dropped, garbled, or otherwise poor quality calling simply went away as soon as the client moved to a service where they had a contract with the provider, and the provider had both equipment in the building *and* controlled the entire path to the Central Office.

To be clear, we're completely provider agnostic here, with the expection of our distaste for Internet based phone service.  Our advocacy is based entirely on our broad experience with Vermont's unique (and sometimes frustrating) lack of bandwidth and connectivity with the outside world, and the issues that are inherent to Internet based phone services.  We don't recommend them.


We have no quarrel with locally delivered SIP service, like that offered by FairPoint.  Since they own the network from the SIP gateway all the way to the PSTN, your contract with them will cover any issues you may experience (which we would expect to be rare, for all the reasons discussed above).  The 'bad' SIP services are the ones that rely on the public Internet for delivery of service.

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