On Thu, Feb 17, 2011 at 11:44 PM, Bruce N <[email protected]> wrote:
> 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). > Bruce, You've piqued my curiosity. I agree that a 1000hz (or so) tone doesn't seem like 'noise' or signal corruption. The frequency you identified is suspiciously close to a Milliwatt test at 1004hz. Is there any chance that there's something weird in your dialplan and you're generating that? Otherwise, maybe a test tech ordered a Milliwatt test and it got left on from the CO side. If it's a new circuit, maybe the install tech ordered the test and didn't cancel it. Having said that, I thought that most milliwatt tests were dialed, not turned on from the CO. I've had cases where work was ordered on one pair or circuit and because of an error in communication between the repair tech and the switch tech, the work was done on the wrong line. If it's not a new circuit, maybe someone was working in the area and messed up your circuit while trying to fix another. What's the level of the audio? Is it faint or is it at conversational volume? Out of sheer curiosity, could you email me the WAV file you recorded? Dave
