> Nick Voth wrote: >>>> Hello folks, >>>> >>>> I need another set of eyes on this. We have a new channelized DS3 >>>> plugged in > to a Cisco 7206-VXR with a PA-MC-T3 card. We can't seem to >>> get rid of >>>> the Line Code Violations and P-bit Coding Violations. See what we've done >>>> below this output... >>> Try putting a 12 db attenuator on the transmit portion, then re-try your >>> loopback. We've found that the PA-MC-T3 cards tend to overdrive the DS3 a >>> bit, and the only way that we've been able to get rid of the errors is >>> attenuating the transmit load. >>> >>> Cisco makes a kit for this, but the part number escapes me now.. Try >>> searching for DS3 Attenuator on google.. >>> >> >> Interesting, you're saying to put an attenuator on the transmit portion of >> the card. Some of the Cisco documentation is saying to put it on the receive >> portion. Is there any way using the "show controller" output to tell which >> one has the "hot" signal? > > The "cablelength" command can be used to reduce the transmit signal > (shorter length reduces signal). Too hot of a transmit level will > result in far end errors, not near end errors. > > In our experience, when attenuators are needed, it has been on the > receive side of the card. > > There are 75 ohm variable/stepped attenuators made for the cable > television industry that can be useful to dial in the right value, then > replace with a fixed pad of that value. One example here: > > http://www.kayattenuators.com/manual_step_attenuators.htm > > These can occasionally be found at ham radio swapmeets and the like > pretty cheap. Make sure you get the 75-ohm version. > > -- > Jay Hennigan - CCIE #7880 - Network Engineering - [EMAIL PROTECTED] > Impulse Internet Service - http://www.impulse.net/ > Your local telephone and internet company - 805 884-6323 - WB6RDV
I just wanted to post a follow-up to the Line Code Violations we were having. It was definitely the inbound signal from the DS3. We put a 10 db attenuator in line and she's running clean! If anyone needs a good source for them, we found the 75 ohm versions here: http://www.smelectronics.us/bnc,fattenuators.htm They are a little pricey, but they have a lot of them in stock and got them to me over night. Thanks for everyone's help. -Nick Voth _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
