Good afternoon, all. Here is a strange one for you.
We get dial tone from Frontier. Last time I checked, we connect to a Nortel DMS remote switch which backhauls over SONET all the way to a Frontier switch co-located at a Verizon CO in Philadelphia. Don't know if this is still the case. We are in area code 610, a split from 215 decades ago.
Every day I call a number in the 215 NPA, a number which has not changed in almost 50 years. They get their dial tone form an Alcatel-Lucent FiOS ONT, installed well over 10 years ago in the "original" FiOS phone configuration, i.e., a two-way 64 kbps channel is carved out of the ATM stream between the ONT and the CO, and their line appears/appeared at a 5ESS just like any other DS0. The 5ESS is/was located in Morrisville, PA. Again, don't know if this is still the case. Probably not.
Now for the malfunction: For a couple of days now, when we call the 215 number, we hear a couple of spurts of "audible ringing," then the SIT tone followed by "your call cannot be completed as dialed etc." Prepending a "1" or leaving it out makes no difference.
Now for the bizarre: Last night, we decided not to hang up after the SIT tones. The tones and the advice to learn how to dial a phone repeated once, then dead air. No off-hook howler, just the proverbial crickets. Patiently we wait... don't know why, just stubbornness. Finally, after several minutes of white noise, the called party picks up the phone and says "Hello?" How many times did their phone ring? Once.
Anyone ever seen this?
Speaking from a secure undisclosed location.