I think this may be a question for some of the long-time telecommunications gurus. I have some phone numbers with Flowroute, and I’ve been using them for a while. However, we recently begun having problems with inbound calls to a few of our DiDs that seem to be in the same area code. People would call in, hear ringing for a long time, eventually make it through, only to hear garbled audio. Other people would call in and it would ring through just fine with crystal clear audio. One strange thing we noticed was that on the calls that wouldn’t work, we would notice multiple invites coming from Flowroute before we were able to answer the call.
I thought, maybe this could this be a problem with our trunk config. So I tried bypassing our server completely, and just forwarded the call from flowroute to an external number. Same problem.
Then we tried routing another number we have with flowroute to the server with a different area code, and that number rings through fine with good audio.
All this time, the problem with the original DiD wasn’t happening on every call, only to certain callers. So I decided to find the pattern. I checked the numbers that had difficulty calling in with a carrier lookup, and found that all of them are originating from Sprint, Google Voice (our numbers), or other Flowroute numbers. AT&T and Verizon both seem to work perfectly 100% of the time.
The number that is having issues is one we ported into Flowroute. This port happened a long time ago, and worked fine for a while until recently, but could this be a clue?
We’ve been in touch with Flowroute and they’ve sent the information to their peer. However, their peer is apparently not able to reproduce this problem. I plan on continuing to communicate with them to try to get this resolved, but I thought I would check here to see if any of you guys had suggestions for next steps. Obviously our client doesn’t want to switch numbers, so that’s out of the question. Should we contact Sprint and see if they can help us? If so, who should I ask for when calling to get someone who could actually look at the details of the call flow?
This seems like a crazy problem, and I thought it might interest you all. Let me know if you have any suggestions. Thank you.