Intermediate Network Woes: A Tale of Mobile Disconnect 

A savvy client of mine who sells hosted VoIP services recently called me with a serious problem. Calls made to my client’s customers from some mobile devices supported by two wireless providers suddenly -- and devastatingly -- weren’t completing. Calls completed, and then suddenly stopped working. The callers got either fast busy signals or ring-never-answers. To be polite, everyone was, um, annoyed.
 
Ultimately, we determined the root cause to be a translation problem somewhere between the caller and intended called party, but identifying where, precisely, the ball was being dropped was quite a challenge. During our research, we found that the calls in question never reached my client’s underlying provider. At the same time, the large wireless providers (two of the biggest), knew that the calls successfully left their networks. What none of us knew was the identity of the third party in place between my client’s underlying provider and the providers whose mobile devices couldn’t connect (again, these two providers are major players in this market). However, even if we could identify the intermediate provider (more on this in a minute), it’s unlikely that anyone from the company would have spoken with either me or my client since we had no direct contractual relationship with that carrier -- or even a method of discovering it.