atcomsystems.ca/forum Forums Other TDM Phone Systems Sprint - Tadiran Telephones & Systems Tadiran IPX500 and Fax Problems

I wasn't sure if this should go in the T1 forum or not. We've been unable to get faxes working with our Coral. We can send faxes to another fax machine hooked up to an FXS port, but we cannot connect any faxes through our PRI. Even if we force training down to 2400 baud on the fax machine/modem. We've tried 3 different fax machines and a fax server.

The strange thing is that modem call work fine. Connections at 9600 baud go out no problem. We haven't tested higher speeds.

We had the LEC (MCI) run tests last night and they said it failed to our CSU, and we're going to try swapping that out today, but doubt seriously that thats the problem.

The PRI has been rock solid for voice calls until we got some "troubleshooting" from verizon yesterday. Now we get dropped connections with code 44 errors when we try to call sporadically.

Any suggestions?

Find out how the PRI is delivered to your site. We've found fax issues on digital loops extended through Pairgain repeaters.

It does come through a pairgain. Would this affect faxes but not modem calls?

Are you using IP? You said FXS. IN the COS for Trunks and everything you have to set FXS (IP ports) to g.7.11. Usually you have to set option 1 under compression if you are running 7.29 it'll never work. Otherwise you gotta look at clocking and whatnot. If it's a straight relular sls card you shouldn't have to touch this.

Also, check you clocking. Your PRI is probably in shelf/slot 0,4 Make sure to check DTDB snd that primary sync is set to the shelf/slot.

The clocking has been checked over by like 3 people at this point. Last I looked at it the primary and secondary sync were both set to 0,4, which is the PRI card.

Using FXS boxes or real analog ports?

The fax machines are hanging off of an 8SLS. We have two cards one with an 8 port daughterboard and another without. We get the same result on both.

Sorry for saying FXS, I'm not the installing tech, I'm the customer getting frustrated and trying to find some suggestions online.

Well, everything points towards the PRI. Have you tried to punch a jack right on the frame to see if the cabling is an issue to the jack?

I ran a new cable this morning right to the smartjack cage directly out of the csu, and then tried with the cage plugged directly into the UDT.

Now for the REALLY strange part. If we disable sync on the UDT card, and just use the internal sync on the coral, we can send faxes. Modem calls go through too, and they have garbage chars, but we can consistently complete faxes at 14.4 with the clocking disabled.

With the clocking enabled, if we increase the attenuation on the CSU we increase our line errors, but are occasionally able to get out a fax. Depends on the fax machines / modems used and it takes forever.

Had a tech testing the line last night. With a hard loop it tests clean. With a TBIRD hooked up it tests clean. Protocol analyser shows errors when we are through it.

They can test to the smartjack ok. They can test to the CSU fine for about 8 minutes and then they throw errors.

I just replaced the CSU and the UDT on tuesday with new equipment because they were seeing the same thing then.

This is really odd. Any more ideas?