After several attempts to work around the issue it became apparent the source of the issue was as the calls were leaving the callers network. The static injected on the line was added by their own carrier as they attempted to call other numbers that routed through the affected equipment in their network and at least one bad cable.
There were at least two separate problems within the network of the western ILEC.
There were two separate repairs (one on the night of the 17th (around 0100 AM PST on June 18) and one on the night of (around 0100 AM PST on June 19) that restored service.
Thank you to all our clients who reported the issue. Our own team conducted about 1,000 test calls in developing the data needed to diagnose the issue. We thank our partner carriers for their cooperation and their speed in resolving the difficult issue.
2020.06.10 Update. This issue has been acknowleged by upstream carriers as a larger issue.
In effort to speed resolution of the issue we have completed and logged several hundred test calls complete with call recordings. We are currently working with our carrier partners to furhter isolate the issue to help them locate the source of the noise (which seems to be analog in nature) and implement a repair. We will continue to monitor the issue and push toward a resolution. Thank you!
2020.06.09 Original Post
We received a few reports of a crackling noise heard while placing calls from outside our system (cell or remote phone system or PSTN) to numbers on our system. In what seems to be a noticable but low percentage of total received calls the caller reports hearing moderate to severe "crackling".
Investigating calls reported which were being enabled for recording showed no evidence of the crackling noise, but a couple reporters managed to capture the sound of the call. The sound appears to be analog in nature, and by analyzing call reports we have determined the issue seems to be on the carrier network and is possibly a TDM / PSTN network.
We have started tickets with upstream carriers to confirm our findings and get the issue repaired.
At this time the issue has not been reported to affect any outbound calls or any inter-office / internal calls.
We will post updates to this article. If you are affected please open a ticket with any details you can provide.
BitBlock Systems, Inc.