DTMF-Relay rtp-nte issue

Unanswered Question
Jan 25th, 2008

Dear All!

If anyone can help me with this issue, I would be very thankful.

This is the scenerio:

PSTN Phone->A SoftSwitch->Cisco AS5300->ISDN Switch(PBX) where user is asked to enter his account/pin number which should DTMF tones to authenticate him.

What happens is ISDN switch can recogniz only first digit entered. Later digits are not received.

In order to figure out the problem I performed following test:

I let the user callthought ISDN switch without authentication. The call is connected in following manner

Phone->A SoftSwitch->Cisco AS5300->ISDN Switch=>Phone2

Now in order to test the DTMF Pass-Thru. I press some digits on Phone1 and hear an on-going tone on phone2.This on-going tone(peeeeeeeeeeeeeeeep) , later digit presses are not heard on phone2. This on-going tone gets lost only if i hang-up.

On the other hand if i perform the same process in reverse order i.e. from phone2 to phone1 things work just fine. i hear multiple tones, each time i press a new digit.

The ios version which I am using is the latest available for this model as5300 c5300-is-mz.123-24a.bin which does include DTMF Feature supports over SIP.

I correct configuration as far as i know. I have searched the web for 2 days and all references told me to use this config. Here it is:

dial-peer voice 49 voip

incoming called-number 49T

voice-class codec 1

session protocol sipv2

session transport udp

dtmf-relay rtp-nte

dial-peer voice 491 pots

destination-pattern 49T

progress_ind setup enable 3

progress_ind alert enable 8

translate-outgoing called 1


port 1:D

voice class codec 1

codec preference 1 g729r8

codec preference 2 g729br8

codec preference 3 g711ulaw

codec preference 4 g711alaw

codec preference 5 g723r63

codec preference 6 g723r53

codec preference 7 gsmfr

codec preference 8 gsmefr

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Paolo Bevilacqua Fri, 01/25/2008 - 07:13

So basically the 5300 is doing SIP with "softswitch" ? The alternative to rtp-nte, is sip-notify. Can you try that ?

mazhar996 Fri, 01/25/2008 - 07:28

Thank you for the answer.

somehow sip-notify is not available although I am using the latest version of ios available for 5300 c5300-is-mz.123-24a.bin

But cisco docu says sip-notify and all options other than rfc can only be used in pure cisco environment, and in case a third party device is used one has to use rfc when using sip. Or am I wrong in my perception?

Paolo Bevilacqua Fri, 01/25/2008 - 07:50

Hi, actually the very latest IOS for 5300 is 12.4(15)T2, same as for all other routers.

Interoperability for passing DTMF can be an issue. Since SIP notify is a standard too, I can image that other devices do implement it as well, however I don't have specific case or references.

mazhar996 Fri, 01/25/2008 - 08:00

Thank you bevilacqua!

let me try with all other options, I will update you on this as soon as possible.

i really appreciate your efforts.

but as far as the ios version is concerned, if i go to http://tools.cisco.com/ITDIT/CFN/Dispatch?act=rlsSelect&task=search&searchby=platform

and look for as5300 , the latest release is 12.3.24a , this is perhaps because as5300 has end of sale.

with sincere regards

Paolo Bevilacqua Fri, 01/25/2008 - 08:08

Hi, some info on CCO can be wrong.

If you use ftp://:@ftp.cisco.com/cisco/ios

You can easily browse all the IOS images for all the platforms.

Only, you will not see the images supporting encryption, that are accessed in a different way.

Hope this helps, please rate post if it does!

jonathan.dixon Mon, 02/11/2008 - 07:03

Hi there,

Noticed this topic on cciev.wordpress.com before I saw it here so i've replied there, but in case you don't get a chance to check it there:

I have the same issue with SIP, h323 is fine, what version of dspware / vcware are your VFC(s) running? It will tell you if the version is lower than required, eg:

vgw01#show vfc 2 version dspware

DSPWare version in VFC slot 2 is 3.4.51L

Firmware version mismatch for bundle AS5300 VCWare

- version found (7.40) is lower than minimum required (11.41)

Firmware version mismatch for bundle AS5300 C542

- version found (3.4.51L) is lower than minimum required (4.1.41)

vgw01#show vfc 2 version vcware

Voice Feature Card in Slot 2:

VCWare Version : 7.40

ROM Monitor Version: 1.3

DSPWare Version : 3.4.51L

Technology : C542

Firmware version mismatch for bundle AS5300 VCWare

- version found (7.40) is lower than minimum required (11.41)

Firmware version mismatch for bundle AS5300 C542

- version found (3.4.51L) is lower than minimum required (4.1.41)

Will upgrade mine at some point but they're production boxes so I can't do it during the day. Let us know if you come up with anything and i'll do the same. I am running IOS 12.3(15a).



jonathan.dixon Fri, 04/04/2008 - 03:49


I guess you've solved your issue by now but FYI I finally got around to upgrading the VCWare on our AS5300 VFCs and it fixed the DTMF issue.

Now running IOS 12.3(15a) and VCWare version 11.45 with no issues.




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