2911GW, mgcp and Fax issue.

[Waldo Roca Martin]

Hi everyone.

I just have installed a new branch for a costumer that include a 2911 with E1 primary for external calls and registered to a CUCM using a mgcp.

So, The CUCM have sip trunks connected to a Right Fax application. primary-> mgcpGw--->cucm sip--->right fax

The problem is the fax have error at the midle of the recepcion and many of them appear cut off. We have cheked send the fax to fax machine (instead of right fax) using ATAs and we have the same problem.  primary-->mgcpGW-->cucm-->ATA---Fax machine.

But depende of the fax machine which is sending the Fax, some works always others never.

The CUCM is 7.1. and this is the mgcp configuration.

SANPOR_2921_1#show run | s mgcp

pri-group timeslots 1-31 service mgcp

ccm-manager mgcp

mgcp

mgcp call-agent 168.124.50.12 2427 service-type mgcp version 0.1

mgcp rtp unreachable timeout 1000 action notify

mgcp modem passthrough voip mode nse

mgcp package-capability rtp-package

mgcp package-capability sst-package

mgcp package-capability pre-package

mgcp package-capability srtp-package

mgcp package-capability fm-package

mgcp default-package fxr-package

no mgcp package-capability res-package

no mgcp timer receive-rtcp

mgcp sdp simple

mgcp validate call-agent source-ipaddr

mgcp fax rate 14400

mgcp fax t38 ecm

mgcp fax t38 ls_redundancy 2

mgcp fax t38 hs_redundancy 2

mgcp fax t38 gateway force

mgcp profile default

IOS C2900-UNIVERSALK9-M, Version 15.1(4)M3,

We use this configuration in another branchs and it works fine.

Any ideas?

Thank you for avance

Best Regards.

[Waldo Roca Martin]

Without T38 the fax to  rightfax doesn't work

Here you have the traces.

physical fax called number

3589499

3589419

3589679

4220110

Right fax to right fax.

3589409

3589629

[Ayodeji Okanlawon]

Did the physical fax work?

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"For the love of God is broader than the measure of man's mind And the heart of the Eternal is most wonderfully kind"

[Waldo Roca Martin]

Yes

[Ayodeji Okanlawon]

Waldo, Well Glad thats working..Atleast we are making progress.

Looking at tha trace I can see that the fax to right fax is not using the correct codec. Its using G729..

+++Trace for rightfax++++

Jun 22 10:26:23.982: MGCP Packet sent to 168.124.50.12:2427--->
200 152213 OK
I: 10

v=0
c=IN IP4 7.48.123.2
m=audio 30610 RTP/SAVP 18 100
a=rtpmap:18 G.729/8000
a=fmtp:18 annexb=no
a=rtpmap:100 X-NSE/8000
a=fmtp:100 192-194

+++This is thetrace for working fax+++Its using G711u

Jun 22 10:29:51.666: MGCP Packet sent to 168.124.50.12:2427--->
200 152357 OK
I: 1D

v=0
c=IN IP4 7.48.123.2
m=audio 23380 RTP/SAVP 0 100
a=rtpmap:100 X-NSE/8000
a=fmtp:100 192-194

NB: That the mline= media attribute line with RTP/AVP profile numbers as follows: 0=G711u and 100=modem-passthorugh

So calls to right fax need to use G711ulaw because the mgcp config for modem -passthrough is set to use G711u.

This config: mgcp modem pass-through voip mode nse (uses G711ulaw as the default codec)

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"For the love of God is broader than the measure of man's mind And the heart of the Eternal is most wonderfully kind"

[Waldo Roca Martin]

Really?

I Can't beliebe I have checked this many times.

Let me check again.

Yes, the regions between the gateway and sip trunks are in G711

Why the gw would be sending the fax in g729?

edit: Use mgcp modem passthrough  codec g711alaw will fix something? We use alaw here in europe.

thank you

[Ayodeji Okanlawon]

Waldo,

The call to 3589629 used the correct codec. But it failed too. This has to do with the configuration on right-fax. This is because after the call was setup, there was no fax switch over. This may be beacuse right fax is configured to use T.38. ( i am not very familiar with right-fax) So in that case it looks like right fax can only do T.38. We will have to re-configure your gateway for T.38.

Did you setup right-fax? what fax protocol did you use..Are you willing to try and re-configure for T.38?

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"For the love of God is broader than the measure of man's mind And the heart of the Eternal is most wonderfully kind"

[Waldo Roca Martin]

No sorry we dind't cofigure Right-Fax. I can't access to it. Just to check if they recive the faxes.

And for T38,  is my initial configuration correct?

Thank for the help

[Ayodeji Okanlawon]

Ok...Lets switch back to T.38 then.

On VG204 and MGCP gateway please configure...

no mgcp modem pass-through voip mode nse

mgcp default-package fxr-package

no mgcp fax t38 inhibit

mgcp fax t38 nsf 000000

Please do test calls and send the ff:

Debug isdn q931

debug mgcp packet

debug voip vtsp all

debug fax relay t30 all-level-1

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"For the love of God is broader than the measure of man's mind And the heart of the Eternal is most wonderfully kind"

[Waldo Roca Martin]

The righ-fax donesn't work either with t38.... strange. The fax make a connexion but don send anything I attach the logs. Whit the initial configuration unless works with cuts.

This is the currently configuration of the gateway

pri-group timeslots 1-31 service mgcp

ccm-manager fallback-mgcp

ccm-manager mgcp

mgcp

mgcp call-agent 168.124.50.12 2427 service-type mgcp version 0.1

mgcp dtmf-relay voip codec all mode out-of-band

mgcp rtp unreachable timeout 1000 action notify

mgcp package-capability rtp-package

mgcp package-capability sst-package

mgcp package-capability pre-package

mgcp package-capability srtp-package

mgcp default-package fxr-package

no mgcp package-capability res-package

no mgcp timer receive-rtcp

mgcp sdp simple

mgcp fax t38 ls_redundancy 2

mgcp fax t38 hs_redundancy 2

mgcp fax t38 nsf 000000

mgcp rtp payload-type g726r16 static

mgcp profile default

This is the currently configuratoin of the VG

mgcp

mgcp call-agent 168.124.50.12 2427 service-type mgcp version 0.1

mgcp rtp unreachable timeout 1000 action notify

mgcp package-capability rtp-package

mgcp package-capability sst-package

mgcp default-package fxr-package

no mgcp package-capability res-package

no mgcp timer receive-rtcp

mgcp sdp simple

mgcp fax t38 nsf 000000

mgcp rtp payload-type g726r16 static

mgcp profile default

service mgcpapp

service mgcpapp

service mgcpapp

service mgcpapp

[Ayodeji Okanlawon]

Please remove these two commands

mgcp fax t38 ls_redundancy 2

mgcp fax t38 hs_redundancy 2

Test again while I look at the logs

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"For the love of God is broader than the measure of man's mind And the heart of the Eternal is most wonderfully kind"

[Ayodeji Okanlawon]

From the trace..

200 157884 OK
I: 80

v=0
c=IN IP4 7.48.123.2
m=audio 17418 RTP/AVP 0 100
         
a=rtpmap:100 X-NSE/8000
a=fmtp:100 192-194,200-202
a=X-sqn:0
a=X-cap: 1 audio RTP/AVP 100
a=X-cpar: a=rtpmap:100 X-NSE/8000
a=X-cpar: a=fmtp:100 192-194,200-202
a=X-cap: 2 image udptl t38

a=fmtp:100 192-194,200-202 (pt=100, event type=192-194) This implies that gateway still has modem pass-through enabled. We need to disable it. If you have removed it then we may need to restart MGCP.

T.38 wont work with Modem pass-through

[Waldo Roca Martin]

Yes you right, I have reseted the mgcp process and now I can send fax  to right-fax. But Now I have to check if the costumer can send every  fax corretly as I from my fax I did'n have problems before.

Thank you very  for your help.

T38 I looks better for the right-fax. of 15 faxes, fail 3.

But the phisical faxes don't work properly. they told  me faxes from spain to portugal (branch country) works fine but from  portugal to portugal not. It is a nightmare .

I can't get traces anymore because I dont have access to the GW.

this is the final configuration

VG1  VG2

mgcp

mgcp call-agent 168.124.50.12 2427 service-type mgcp version 0.1

mgcp rtp unreachable timeout 1000 action notify

mgcp package-capability rtp-package

mgcp package-capability sst-package

mgcp default-package fxr-package

no mgcp package-capability res-package

no mgcp timer receive-rtcp

mgcp sdp simple

mgcp fax t38 ecm

mgcp fax t38 nsf 000000

mgcp rtp payload-type g726r16 static

mgcp profile default

service mgcpapp

service mgcpapp

service mgcpapp

service mgcpapp

GW1, GW 2

mgcp call-agent 168.124.50.12 2427 service-type mgcp version 0.1

mgcp dtmf-relay voip codec all mode out-of-band

mgcp rtp unreachable timeout 1000 action notify

mgcp package-capability rtp-package

mgcp package-capability sst-package

mgcp package-capability pre-package

mgcp package-capability srtp-package

mgcp package-capability fm-package

mgcp default-package fxr-package

no mgcp package-capability res-package

no mgcp timer receive-rtcp

mgcp sdp simple

mgcp validate call-agent source-ipaddr

mgcp fax rate 14400

mgcp fax t38 ecm

mgcp fax t38 ls_redundancy 2

mgcp fax t38 hs_redundancy 2

mgcp fax t38 nsf 000000

mgcp fax t38 gateway force

mgcp rtp payload-type g726r16 static

mgcp profile default

There are 2 CCIEs in my company and any of them culdn't help me today. Unless I wasn't alone

Thanks Aokanlawon

Edit: Sorry, I didn't see remove these comands

mgcp fax t38 ls_redundancy 2

mgcp fax t38 hs_redundancy 2

I will try tomorrow.

[Ayodeji Okanlawon]

Waldo,

I am glad I could help. In your GW1 and GW2 configuration you have conflicting configuration. You have enabled both nse based T.38 and Standard based T.38. You shouldnt do this because I am not sure your right fax will support nse based. I did suggest to remove those configurations..so configure the ff:

no mgcp fax t38 ecm

no mgcp fax t38 ls_redundancy 2

no mgcp fax t38 hs_redundancy 2

no mgcp fax t38 gateway force..............This is enabling nse based T.38.

remeber to rest mgcp

Also configure this on VG1 and Vg2

no mgcp fax t38 ecm

Please do a test call from

1. Physical fax

send the ff

Debug isdn q931

debug mgcp packet

debug voip vtsp all

debug fax relay t30 all-level-1

2. right-fax

Debug isdn q931

debug mgcp packet

debug voip vtsp all

debug fax relay t30 all-level-1

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"For the love of God is broader than the measure of man's mind And the heart of the Eternal is most wonderfully kind"

[Waldo Roca Martin]

Hi Again.

Thanks but finaly the problem was fix it. My partner connected to the client and he changed some configuration. Now every fax works. This is the final configuration.

GW

ccm-manager fallback-mgcp

ccm-manager redundant-host 168.124.50.11

ccm-manager mgcp

no ccm-manager fax protocol cisco

ccm-manager music-on-hold

!

mgcp

mgcp call-agent 168.124.50.12 2427 service-type mgcp version 0.1

mgcp dtmf-relay voip codec all mode out-of-band

mgcp rtp unreachable timeout 1000 action notify

mgcp ip qos dscp cs3 signaling

mgcp playout fax 700

mgcp package-capability rtp-package

mgcp package-capability sst-package

mgcp package-capability pre-package

mgcp package-capability srtp-package

mgcp package-capability fm-package

mgcp default-package fxr-package

no mgcp package-capability res-package

no mgcp timer receive-rtcp

mgcp sdp simple

mgcp fax rate 14400

mgcp fax t38 ls_redundancy 1

mgcp fax t38 hs_redundancy 1

mgcp fax t38 nsf 000000

mgcp fax-relay ans-disable

mgcp rtp payload-type g726r16 static

VG

!

ccm-manager redundant-host 168.124.50.11

ccm-manager mgcp

no ccm-manager fax protocol cisco

ccm-manager music-on-hold

ccm-manager sccp local FastEthernet0/0

!

mgcp

mgcp call-agent 168.124.50.12 2427 service-type mgcp version 0.1

mgcp rtp unreachable timeout 1000 action notify

mgcp ip qos dscp cs3 signaling

mgcp playout fax 700

mgcp package-capability rtp-package

mgcp package-capability sst-package

mgcp default-package fxr-package

no mgcp package-capability res-package

no mgcp timer receive-rtcp

mgcp sdp simple

mgcp fax rate 14400

mgcp fax t38 ls_redundancy 1

mgcp fax t38 hs_redundancy 1

mgcp fax t38 nsf 000000

mgcp fax-relay ans-disable

mgcp rtp payload-type g726r16 static

!

mgcp profile default

!

Thanks .

Regards.