Fax problem/Bad quality

[derveniss]

Here is the topology:

fax->ata->cucm->h323 VG-------->mpls---------->h323 VG->PBX (through E1) ---> fax

I have a very very bad fax quality or half pages ONLY from this way..

Any ideas of wha to check..?

Thanks

[derveniss]

on the same topology, SOMETIMES, when i call from ip phone to a phone that belongs to pbx, there is a delay (2-3 secs) after answering..

What i mean is tha I speak and the other side does't hear me for 2-3 seconds.. Then everythin is ok

[Manoj Srinivas · Accepted solution]

Hi.

Sounds like a network issue.

Try pinging from H323 gateway at ATA end to the other and check the delay. Also, check for any slip errors, line code violations and path code violations in the E1 line. You can check this by "show controller e1 x/y/z.

HTH!

Regards,

Manoj

[derveniss]

Hello and thanks for the reply,

The ping is ok but I get this output on the remote site voice gateway:

Router#sh controllers e1
E1 0/1/0 is up.
Applique type is Channelized E1 - balanced
Description: ### E1 PBX LINK ###
No alarms detected.
alarm-trigger is not set
Version info Firmware: 20100222, FPGA: 13, spm_count = 0
Framing is CRC4, Line Code is HDB3, Clock Source is Line.
Data in current interval (157 seconds elapsed):
0 Line Code Violations, 0 Path Code Violations
11 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
11 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
Total Data (last 24 hours)
0 Line Code Violations, 0 Path Code Violations,
6395 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins,
6395 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
Router#

This is the PRI that is connected to the Siemens PBX.. Too many slip secs..

[Tracy Larson · Accepted solution]

that will definately be your issue. Slips and fax = bad mojo. Check your clocking setup.

[barry · Accepted solution]

Yup... that will be it. make sure you have "network-clock-select" configured on your E1 card.

[Manoj Srinivas]

ah I guess you will have to check the slip errors first. You will asways have Fax issues with slip errors.

Please make sure the clocking is configured correctly. Check for "network-clock-select" command.

Thanks,

Manoj

[derveniss]

Problem solved.. It was slip related indeed..

Thank you all!

[derveniss]

Another customer has the same problem with the faxes!!

I have noticed many slip errors..

But as I see, the network-clock-select command is there!!

Also I have confirmed that clocking is provided by the other side.

What else I have to check?

[paolo bevilacqua]

Send show controller, and show network-clocks.

[derveniss]

Here is attached the output..

The 0/3/0 has the problem

thanks

[paolo bevilacqua]

Are you connecting to different telcos ?

The two circuits are not syncronous, and so you get slips.

You can try moving clock selection to 0/3/0 but the slips will shift to 0/2/0.

Unfortunately there is little you can do about it, beside buying more hardware.

[derveniss]

0/2/0 is a PBX, 0/3/0 is my telco

[paolo bevilacqua · Accepted solution]

Take clock from telco, give to PBX.

End of troubles.