DTMF on SPA525G/G2

[mbram1313]

Hello Everyone,

Has anyone else had issues with DTMF on the SPA525G2 when going out SIP trunks? I have a customer that we just rolled out 16 of these phones on a UC560 for. When hitting inbound our outbound IVRs over the SIP trunks, 3/4 of the DTMF digits never make it to the other side. However, when you add a 7965 over the same trunks, the digits register perfectly. Any thoughts?

Thanks...Matt

UC560_8.1.0 Software Pack

[mbram1313]

TAC is on the case

[bjames]

Matt do a search here on SIP DTMF and you will see tons of issues on this. We had a customer with the same issue to an

ITSP that was using an Asteriks (sp?) Gateway. There are known issues with some gateways. I think in our case Cisco worked directly with the ITSP to correct the issue.

Even though these are suppose to be standards, companies interperate them differently.

Good luck, I know I wasn't much help

Bob James

[mbram1313]

Thanks Bob,

Still working on it!

We are getting closer. Looks like the rtp-payloat type nte-tone payload is playing a part in the dial-peer. We are getting closer...I'm ready for a beer!

Matt

[David Trad]

Hi Matt,

I suspect that the SPA phones in general have a problem with DTMF tones, be it SIP trunks or even dialing to the CUE I seem to be hitting this issue, right now the 7900 series phones are not having the same problem, you will see I have also posted about this but my grievance at this stage is it working happily with the CUE, from there I can tackle the other issue I guess.

Here is to hoping we can both resolve our issues

Cheers,

David.

[mbram1313]

Hey David,

It seems that the (making an assumption here) firmware hard sets the rtp payload-type nte-tone, which is under the dial-peer voice xxx voip menu. You cannot set that from the ephone settings. I'm waiting back to here from the carrier as to what the payload type should be on the metaswitch. I think that the dial-peer will default this to 101. However, why would a different firmware not be experiencing the same problems on the same dial-peer? That to me pretty much nails it donw to the SPA phone. I know my customer and she is going to want these things yanked out . One thing I was thinking about was that if this is a limitation to the light skinny protocall that these SPA phones use???

I'm not sure why you are experiencing issues to the CUE. Those dial-peers should be set to dtmf-relay sip-notify. I would set these on this production unit, but I don't think the metaswitch will allow it.

Regards,

Matt

[David Trad]

Hi Matt,

However, why would a different firmware not be experiencing the same 
problems on the same dial-peer? That to me pretty much nails it donw to 
the SPA 

Well there are two paths to this, one is the phone to the UC (This can have potential problems) and the other is the path to the ITSP which is controlled by the UC. The problem is you have to debug both paths to narrow down on the problem and this is usually where it gets cumbersome and infinitely frustrating, but I find that a little patience and a cool head can usually navigate you through to a resolution (I am often quick to temper when under pressure and the client is not a happy camper).

In the past firmware upgrades to the 7900 series phone introduced new feature sets, or changed specific behavior to the phones, but they rarely introduced new bugs, but with the SPA phones it seems every upgrade fixes one thing then seems to break another, or creates a conflict in operation with the UC, why it happens is beyond me.

I must point out that making payment changes to the Payload is a CLI configuration change and you should make sure you have support working on this with you, but if this is required then the ITSP can make the required adjustments to their equipment as well and this would be more ideal for you so you do not have a box that has specific configurations set on it.

Remember this, if you manage to get everything working you should immediately use CCA to make a backup of the system, this way if the something happens to the system you are not left working out how to resolve this problem when restoring, it should just happen from the backup.

Anyways back to battling my fires and putting them out

Cheers,

David.

[mbram1313]

Hey David,

I have trapped and packet sniffed both on the POP side and on the inside of the firewall. I can verify that the RFC2833 events and payload are going through and look identical (though you cannot determine the rtp payload type for DTMF from wireshark) for each of the IP phones (SPA525G2 and 7965), 7-events and their corresponding payload. You can even hear the event firing from the remote end, but with no tone mdulation; except for the few cases where the DTMF packets are translating at the carrier. The more I look at it, it looks like the ITSP is not accepting the default payload type 101. In the firmware of the station (7-4-6), they must be doing something differently and it is not being converted at the UC router, which my guess is that it has to do with the lightweight skinny these phones use. TAC is now stummped and it is being escalated. Looks like I walked right into a dusey on this one

Thanks for your comments...Matt

[David Trad]

Hi Matt,

Thanks for the update

In the firmware of the station (7-4-6), they must be doing something 
differently and it is not being converted at the UC router, which my 
guess is that it has to do with the lightweight skinny these phones use.
 TAC is now stummped and it is being escalated. Looks like I walked 
right into a dusey on this one 

I know this may not be of any comfort to you, but i just upgraded to phone load 7-4-8 and the DTMF issue to the CUE seems to have gone on holidays \o/

Can i strongly suggest to you to do a firmware upgrade if you are still on 7-4-6 and give it another shot, it is a small exercise and may be worth it for you to do it.

I cannot say if the Skinny SCCP is an issue or not, I mean it really is only just a cut down version of the full SCCP anyway, but alas I have never delved that far into it to try and identify the differences, these days I am just happy if it works

Cheers,

David.

[mbram1313]

Attempting Now

[David Trad]

Attempting Now 

I am rounding up the monkeys for you now to conduct the Cisco Meditation Chant... I'm thinking 20 of them going around in circles with a UC-540 in the middle should do the trick

Good luck

Cheers,

David.

[mbram1313]

Hello Bob,

Do you know what settings the ITSP changed to get it going?

Thanks,

Matt

[bjames]

Matt,

There were three separate issues, one was Cisco's that was a bug (fixed) and the other was issues with the ITSP using a Sonus Gateway and lastly with the ITSP using Digium/Asteriks. Cisco worked with Digium to put out new patches to their gateway.

Here is the drawn out link:

https://supportforums.cisco.com/message/3081587#3081587

Good luck,

Bob James

[Steven DiStefano]

Please do share the result of TAC case and as well what Phone FW running. SWP 8.1.0 has 7-4-6 and there is a 7-4-8 for SPA 525 on CCO, which I would try.

Sent from Cisco Technical Support iPhone App

[David Trad]

SWP 8.1.0 has 7-4-6 and there is a 7-4-8 for SPA 525 on CCO, which I would try.

Yeah well I would if I could get drag and drop working... banging my head against  the wall right now on this one, I swear I need a fire fighters suit right now, I seem to be putting out little sporadic fires out these days...

Anyway not to Hijack this thread, will post the results of a firmware upgrade on my thread when I manage to get the FW uploaded (Will do it manually if I have to as a last resort).

***POSTS AN IMAGE ON THE WALL - BANG HEAD HERE***

Cheers,

David.