Hi Everyone,
Issue with a Bell PRI left me with few bad channels that I thought is never possible with a digital link like PRI. I thought that PRI channels are really created on the go and if there are no ALARMS then it means no noise level on any of the channels. I mean if there is something bad with the copper pair would that effect all the channels which are delivered over different frequencies? or does the noise effect one channel more that the other? So, I am very curious to know why I have Tx of 480 noise level (testing with ztmonitor) on channel 6 for example and Rx of 23 on channel 3. Channels 1-6 all have minor or major issues Rx/Tx noise level issues and the rest to 23 are fine as they show 0/0 in Rx and Tx. Notice all tests were done when no calls going on. So, I recorded the Rx and Tx streams and I see that the Tx stream on Channel 6 is giving me a continuous tone of 1001-1020 Hz. This is varying but mostly staying at 1001 Hz over 10 seconds of recording (tested with GString tuner of Android. Probably accurate to +/- 5 Hz). Two questions: 1- So, I am willing to absorb that my assumptions about noise level on PRI channels was wrong and that there could be some channels with noise level but why is there any Rx noise level at all? It's for sure that Asterisk doesn't create any outbound noise level. And so doesn't the amazing Sangoma card. With Rx of 23 on Channel 3 I have Tx of 0 on the same channel. Probably meaning that Rx and Tx are transfered over different frequencies on a PRI? I know this get's very technical but I am very very much curious to know this from Gurus here. 2- What can be done to fix these issues? and what should I be telling the testing center and Bell techs to get this fixed and put things back to normal --- something in their own jargons would be much appreciated. Anyone with experience, please weigh in. P.S. further, this is unlike white noise level one hears on analogue lines. It's continuous and set at certain frequency and it's very clear. No breaks. I am wondering if this is a CO equipment issue rather than rain or bad copper lines outside. What do you think? Regards,
