Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 

Receiving FAX with ATA

Hello, we have a CCM cluster (5.1), with GW 2821 (VWIC2-1MFT-T1/E1). The voice calls are working great, but a fax connected through an ATA can't receive anything because it doesn't recognize as a data transmission. However it can send fax correctly.

The ATA has the las firmware (SCCP 3.2.3), and is registered in the CCM.

Any idea?

Thanks.

1 ACCEPTED SOLUTION

Accepted Solutions
Silver

Re: Receiving FAX with ATA

Your ATA config seems fine. Please Add the following under the voip Dial peer:

fax rate disable

modem passthrough nse codec g711ulaw

25 REPLIES
Hall of Fame Super Gold

Re: Receiving FAX with ATA

Hi,

Have you configured

"network-clock-select 1 E1 x/y/z" ?

Without that, fax cannot work correctly.

Re: Receiving FAX with ATA

Hola Paolo, I have configured the command "network-clock-select 1 E1 0/0/0" and there is no difference. The disconnect value is 17 (user busy), but the fax receive the call as a voice call.

Thanks.

Hall of Fame Super Gold

Re: Receiving FAX with ATA

Hola

Fax calls are voice calls. I do not understand why "user busy is returned". If you call from a phone, do you hear the fax answering and the fax tones ?

Re: Receiving FAX with ATA

If I call from a phone I hear a tone during few msec. and after only silence. The call is disconnected (cause value 16) after 40 sec. aprox.

Gracias.

Hall of Fame Super Gold

Re: Receiving FAX with ATA

Check "debug isdn q931" with "term mon". There you should see that a fax call is the same as a voice call.

The only difference might be the bearer capability for fax calls to be "3.1 KHz" instead of "Speech". That should not prevent the call to be routed to the ATA.

Re: Receiving FAX with ATA

Here is the output of debug isdn q931 for a fax connection:

*Jul 7 10:48:23.989: ISDN Se0/0/0:15 Q931: RX <- SETUP pd = 8 callref = 0x6300

Bearer Capability i = 0x9090A3

Standard = CCITT

Transfer Capability = 3.1kHz Audio

Transfer Mode = Circuit

Transfer Rate = 64 kbit/s

Channel ID i = 0xA1838F

Preferred, Channel 15

Progress Ind i = 0x8281 - Call not end-to-end ISDN, may have in-band inf

o

Calling Party Number i = 0x2183, 'sssssssss'

Plan:ISDN, Type:National

Called Party Number i = 0xA1, 'ddddddddd'

Plan:ISDN, Type:National

Sending Complete

*Jul 7 10:48:23.997: ISDN Se0/0/0:15 Q931: TX -> CALL_PROC pd = 8 callref = 0x

E300

Channel ID i = 0xA9838F

Exclusive, Channel 15

*Jul 7 10:48:24.169: ISDN Se0/0/0:15 Q931: TX -> ALERTING pd = 8 callref = 0xE

300

*Jul 7 10:48:30.669: ISDN Se0/0/0:15 Q931: TX -> CONNECT pd = 8 callref = 0xE3

00

*Jul 7 10:48:30.713: ISDN Se0/0/0:15 Q931: RX <- CONNECT_ACK pd = 8 callref =

0x6300

*Jul 7 10:48:30.713: %ISDN-6-CONNECT: Interface Serial0/0/0:14 is now connected

to sssssssss N/A

*Jul 7 10:48:33.601: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0/

0:14, changed state to up

*Jul 7 10:49:19.289: %ISDN-6-DISCONNECT: Interface Serial0/0/0:14 disconnected

from sssssssss , call lasted 48 seconds

*Jul 7 10:49:19.289: ISDN Se0/0/0:15 Q931: TX -> DISCONNECT pd = 8 callref = 0

xE300

Cause i = 0x8090 - Normal call clearing

*Jul 7 10:49:19.333: ISDN Se0/0/0:15 Q931: RX <- RELEASE pd = 8 callref = 0x63

00

*Jul 7 10:49:19.337: ISDN Se0/0/0:15 Q931: TX -> RELEASE_COMP pd = 8 callref =

0xE300

Everything seems correctly, but it is not working. The fax report says that the incoming call is a voice call and it doesn't print anything.

Gracias.

Hall of Fame Super Gold

Re: Receiving FAX with ATA

Can you try a different fax machine ?

The next step would be to check the ATA setting as indicated in the "troubleshooting ATA Fax" document.

The further following step would be converting the ATA to H.323.

New Member

Re: Receiving FAX with ATA

Hello,

is the gateway controlled by MGCP?

Bye

Jo

Re: Receiving FAX with ATA

Hello, the gateway is configured wit H323 protocol (not controlled by the CCM). So an incoming call goes to the E1 card (in the 2821 gw), it matchs a DID dial-peer (h323) to the CCM, the CCM makes a translation (from public number to an extension) and then it matchs the internal extension of the fax (in ATA, which is registered as SCCP phone).

This is the ATA config:

LBRCodec 3

AudioMode 0x00350035

ConnectMode 0x90000400

FXSInputLevel -1

FXSOutputLevel -4

The dial-peer:

dial-peer voice 2 voip

description Llamadas entrantes del PRIMARIO

destination-pattern xxxxxxxxx

session target ipv4:yyyyyyyyy

!

dial-peer voice 3 pots

incoming called-number xxxxxxxxx

direct-inward-dial

!

And the translation pattern in CCM:

Translation Pattern: xxxxxxxxx

Called Party Transform Mask: 1828

Thanks.

Hall of Fame Super Gold

Re: Receiving FAX with ATA

Silver

Re: Receiving FAX with ATA

Your ATA config seems fine. Please Add the following under the voip Dial peer:

fax rate disable

modem passthrough nse codec g711ulaw

Re: Receiving FAX with ATA

Hello, it works!!! Thank you very much.

Best regards.

Re: Receiving FAX with ATA

Hi, although it seems working fine, many times we receive the fax incomplete. Usually it stops at the middle of the fax.

Thanks.

Hall of Fame Super Gold

Re: Receiving FAX with ATA

Hi, check "show controllers E1", it must have 0 errors, and 0 slips for fax to work reliably.

Re: Receiving FAX with ATA

Hi Paolo, it has no errors.

Thanks.

New Member

Re: Receiving FAX with ATA

Hi Guys,

I am having the same problem as this posting only difference being i am using 3 bri`s instead of an E1.i have added the network clock 1 BRI0/1/1 but still no change....

I have checked my ATA settings, added the fax rate disable and the modem passthrough nse command to the dial-peers but still no difference.Using H.323.

Any Ideas ??

Hall of Fame Super Gold

Re: Receiving FAX with ATA

Have you configured the ata as per document linked above ?

New Member

Re: Receiving FAX with ATA

Yes 100%...i was thinking of perhaps reloading the router ?? What do you think...

Hall of Fame Super Gold

Re: Receiving FAX with ATA

All fax fails, or just partially ?

New Member

Re: Receiving FAX with ATA

They all fail...

New Member

Re: Receiving FAX with ATA

Hi Guys,

Please see attached my debugs for this issue...thanks !!

New Member

Re: Receiving FAX with ATA

Hi Guys,

I have attached some output for this issue which i have still not been able to resolve :

Anything else i can check please let me know...

Cisco Employee

Re: Receiving FAX with ATA

Can you post a packet capture of the failed call and let us know the IP of the voice gateway and ATA?

Thanks,

David

New Member

Re: Receiving FAX with ATA

Hi,

For security reasons i will not be able to provide the ip addresses for these devices. Is there anything else i can try or look at ??

Cisco Employee

Re: Receiving FAX with ATA

A packet capture is the quickest way to get to the root of the issue. Because you are doing NSE-based passthrough your troubleshooting options are more limited as compared to fax relay where the helpful command "debug fax relay t30 all-level-1" is available. You confirmed earlier in the thread that you have the ATA and voice gateway configured correctly. Most of the time, problems such as yours are config issues. Can you post your configs so that we can double check your setup?

There are debugs on the ATA using prserv that will allow you to confirm the NSE switchover. You can also use the command "debug voip hpi" along with "no debug voip hpi stats" on the voice gateway (warning - this is an intensive debug so make sure you follow the appropriate debugging procedures before enabling this). The HPI debug can be difficult to decode but it shows IOS programming the DSP for passthrough as well as the NSE switchover messages. Additionally, you can repeat the commands "show call active voice brief" and "show voice call " as the passthrough call is occurring to check the DSP stats for issues. Unfortunately, there is not much else that you are going to be able to get from these devices for a passthrough call.

The packet capture is your best piece of troubleshooting information as it shows the NSE switchover messages, confirms a successful transition to G.711, shows network impairments that could be harming the call, and additionally you can extract the G.711 audio from the RTP stream and then figure out from the fax tones if there is a problem in the T.30 negotiation.

I understand your reluctance in posting packet captures and IP addresses on a forum such as this. You may feel more comfortable working directly with Cisco TAC on this type of issue. I hope the troubleshooting information above helps.

Regards,

David

350
Views
25
Helpful
25
Replies
CreatePlease to create content