Unable to receive FAX but able to send FAX successfully.

[dipars1953om]

Unable to receive any FAX but able to send FAX successfully.

Call Flow: 

SIP Provider à CUBE à FXS Port à FAX machine.

Platform: ROM: System Bootstrap, Version 15.0(1r)M16 and System image file is "flash0:c2900-universalk9-mz.SPA.152-4.M3.bin"

We have tried to send some test fax too but we got No answer.

Please find the attached file for the debug. Also the attached file contains the “sh run” and “sh ver” for your reference.

cisco-ani=+4989700735168 and dest=+18642499640 ( faulty FAX machine )

From the debug log I do see that it is getting matched with the incoming dial-peer and then getting matched with the outgoing dial-peer too towards the FXS port but then I am not getting why the FAX is not received by the FAX machine.

Kindly assist. Thanks in advance.

[zdesignstudio]

Is this the only faulty fax machine or are there other? 

What fax protocol does your provider support? Make sure they support T38 and have it enabled from their end. 

Does a normal analog call work on the port?

Also grab sip debugs with "debug ccsip messages". You have pass-through configured but most providers do not support NSE based (Cisco Propietary) switch overs.

[dipars1953om]

Yes we have only one FAX machine. Yes they do support T.38. As we can send FAX successfully.

Unfortunately we do not have any analog phone to test right now.

I do changed my configuration little bit as follows but no luck. Still the same result.

dial-peer voice 99640 voip
description ** Incoming fax from Level3 to gateway**
incoming called-number .
translation-profile incoming fax-in
session protocol sipv2
session transport udp
voice-class codec 1
voice-class sip early-offer forced
dtmf-relay rtp-nte
fax-relay ecm disable
fax-relay sg3-to-g3
fax rate 9600
fax nsf 000000
fax protocol t38 version 0 ls-redundancy 0 hs-redundancy 0 fallback pass-through g711ulaw
no vad
!

voice translation-rule 30
rule 1 /^\+1\(8642499640\)$/ /\1/

voice translation-profile fax-in
translate called 30

dial-peer voice 9640 pots
description ** Level3 -> FXS 0/3/0 **
destination-pattern 8642499640
port 0/3/0
forward-digits all
!

Please find the attached logs and sh run and sh ver.

Thanks in advanec.

[zdesignstudio]

Thanks. Good ole' L3 (CenturyLink). Notorious for not enabling T38.
Im not seeing T38 in the debugs. Can you provide debugs from a successful outbound fax so we can compare?

[dipars1953om]

Thanks for your help. Also please find the attached debug which I have taken today. But still yet to get the good case once again as you requested. If you have some time then please have a look into today's trace. As I see T.38 in debug.

Thanks in advance.

Note: cisco-ani=+4989700735168 and dest=+18642499640 ( faulty FAX machine )

[Balram Vishwakarma]

From the logs I could see that we sent 183 with session in progress at 14:36:09.295 and then for around 43 seconds nothing happens.

Nov 30 14:36:09.295: //438157/A3D3E66F89D0/SIP/Msg/ccsipDisplayMsg:
Sent:
SIP/2.0 183 Session Progress

recieved cancel as standard timeout.

Nov 30 14:36:52.322: //-1/xxxxxxxxxxxx/SIP/Msg/ccsipDisplayMsg:
Received:
CANCEL sip:+18642499640@10.202.143.138:5060 SIP/2.0

This call never switched to fax call and its ended as voice call.
Also you wont see any T38 message(no messages in the logs as well) unless voice call switched to fax.
Please share the log for outbound fax call which is working fine to compare with these logs.
Could you please also share "voice service global" output ?

[dipars1953om]

Thanks for your reply and thanks for your time.

Please find the attached packet capture file. I am trying to get the good case trace. If you have some time, please go through the packet capture and let me know your findings. Thanks in advance.

As per me the FAX machine is not answering the call in proper manner and going OFF-HOOK. 

Also when I am dialing the FAX number normally from my mobile phone I am not getting any FAX tone.

Fax machine model number is a Sharp MX2600N

Note: cisco-ani=+4989700735168 and dest=+18642499640 ( faulty FAX machine )

Please find the voice service part as requested:

voice service voip
ip address trusted list
ipv4 10.150.21.186
ipv4 10.150.21.187
ipv4 8.45.197.5
dtmf-interworking rtp-nte
allow-connections sip to sip
fax protocol t38 version 0 ls-redundancy 0 hs-redundancy 0 fallback pass-through g711ulaw
sip
bind control source-interface Loopback0
bind media source-interface Loopback0

[Balram Vishwakarma]

Hello,

You already found the solution to your issue.

"Also when I am dialing the FAX number normally from my mobile phone I am not getting any FAX tone."

In typical fax call flow called party should do the switch over from voice to fax call but in your case fax machine is doing nothing and the call disconnects with timeout from the provider side.
In your case we wouldn't be able to find out anything in the logs as its the issue with fax itself if you are not getting any fax tone then please get the fax machine tested and verified from the vendor or technician.
I would suggest you to check below.
> Test with some different machine if you are able to receive fax.
>assign this number to different machine and see if it works.

Regards,
Balram
Ex-Cisco TAC