Tapping T1 (PRI) for call recorder

[Snoop168]

We have a T1 (PRI) tap card installed in a server and are attempting to troubleshoot audio quality issues. First want to make sure we are using the optimal tap point. What is the best or preferred location to tap the T1?? Out of the smart jack, CSU or PBX? If you change the tap point does that change the wiring you need to use(straighthrough, cross the pairs or cross flip)? We aren't sure the exact configuration of wiring we need, the manual is not totally specific but leads you to believe straightthrough is the proper way. We started with straighthrough rj48 which gets us audio with one half of the conversation airly clear while the other side (local side) is completely muffled Ive tried other configurations but can't remember getting any sucessful results. Also it was recommended that the cable used to do the tap not be any longer than 10FT. This is next to impossible based on where everything is located. The smart jack is located in the basement and brought to the PBX on cat5e. That run totals probably about 125ft. We tapped at that point and added about another 50ft to the recorder. We were going to move the smart jack next to the PBX if we think the length after the smart jack may be an issue... Either way we would always be more than 10FT from the server. This could also have nothing to do with the wiring itself and merely be configuaration of the frame settings etc which is way over my head and the comapny installing the recorder is dealing with that aspect. Anyone have any recommendations or any starting points? Even some certainty on the wiring type to use would be a great help. We have a TAP card not a TERM.

Thanks in advance for all your help.

 

[lopes1211]

Your recorder is 50' from the tap point? So 50' from the tap, then 50' back to the tap? That makes your 125' t1 cable now 225' total (almost double). You probably wont get this right until you relocate the recorder near the PBX and conform closer to the recommended 10' (20' total to & from the tap) versus the 100' to & from the tap you're at now.

-CL

 

[Snoop168]

Ultimately you think its the distance?? The tap point is not stealing the pairs and then giving them back to the PBX. its simply monitoring them so im not sure if you should necessarilly double the distance... The actual amout of cat 5 involved in the setup is 125 plus 50 plus if you want to count the patch cord going to the pbx you can add another 10. so 185 total. But like i said I dont think you should consider the fact that the t1 is travelling down to the recorder and then back to the server. Its literally split out of the smart jack. One cable goes to the recorder one cable goes to the PBX. So from the smart jack the PBX is 135ft away and the recorder is 175 feet away but they both share the same first 125 feet. so the total amount of wire involved is like I said aproximately 185ft.

Really the only feasable thing I can do right now is move the smart jack up to the room where the pbx is. That would eliminate that 125 ft run AFTER the smart jack, but it would instead be before the smart jack instead on the CO side. I'm thinking the circutry would prefer the added distance before the smart jack because after all 125 ft is probably not that much considering the phone company runs miles. This would then reduce the total amount of wire after the smart jack to 60 ft. (50 to the recorder 10 to the PBX)

Thanks again. But ultimately do you think the length is my starting point, or is the audio quality issues possibly related to something such as misconfigured frame settings or compression settings.

 

[lopes1211]

the taps I've seen usually have 4 jacks. CO in, out to recorder, in from recorder, out to PBX. If you only have 1 patch cord into the recorder, it sounds like you have something different. I'm not necessarily saying it's an issue with overall length, more of impedance/LBO mismatch of the 2 CPE points. I would move the recorder near the PBX and use the 10' lengths they recommend.

-CL

 

[jrgood0852]

I worked for a company that did T1 upgrades (from 56k) at Barnes & Noble stores. We connected direct to the smart jack. This one store I had to run a patch cord through the ceiling to where the router was to replace the 56k circuit. It was taking errors when we went to test and we couldn't get the errors to go away. As a last resort I relocated the smart jack next to the router.........problem solved! I think you should relocate the smart jack near to the equipment. As long as you have one of those special keys (who doesn't?). Thanks.