Mitel 5000 SIP trunking DTMF working intermittently

[Cardine]

As the title suggest i have dtmf working "sometimes", i have tried changing the DTMF to RFC2833 as stated by the provider but it still does the same time....any other settings i should be aware of?

Thanks for your help.

 

[Cardine]

Update :

provider say i'm sending sdp payload 96 and need to be sending 101, can't find anything on this...

Anyone done sip on the 5000 before?

Gonna try TS see if they can assist.

 

[IrwinMFletcher]

I haven't used the 5000, but it should be possible to change the default value. Having said that, whatever value you set on the system would be what YOU want to receive, you have to send what the far end tells you to in the SDP of the SIP message. If the 5000 is ignoring that, then it's a problem in their code/design.

Can you supply a SIP trace to verify?

 

[Cardine]

Irwin, thanks for your reply.

I contacted Mitel TS and they have asked for the same thing...looks like i'm going to have to visit the site (remote location) to do this...

 

[IrwinMFletcher]

Good luck, let us know the results.

 

[InspironXD]

I ran a trace and this is what I get:

SIP/2.0 200 OK
Via: SIP/2.0/UDP X.X.X.X:5060;branch=z9hG4bK-eb251f-4eb9a14b-9cd2c1a-472bd
From: "WIRELESS CALLER" <sip:XXXXXXXXXX@X.X.X.X>;tag=63e65a45-13c4-4eb9a14b-9cd2c1a-34216a14
To: <sip:0667@X.X.X.X>;tag=Mitel-5000_4202495480-901
Call-ID: CXC-435-63355150-63e65a45-13c4-4eb9a14b-9cd2c1a-1fb22826@X.X.X.X
CSeq: 1 INVITE
Contact: <sip:0667@X.X.X.X:5060>
Allow: NOTIFY,REGISTER,REFER,SUBSCRIBE,INVITE,ACK,OPTIONS,CANCEL,BYE
User-Agent: Mitel-5000-ICP-5.0.4.73
Content-Type: application/sdp
Content-Length: 248

v=0
o=Mitel-5000-ICP 1084586900 1320788252 IN IP4 255.255.255.255
s=SIP Call
c=IN IP4 255.255.255.255
t=0 0
a=sendrecv
m=audio 6168 RTP/AVP 0 96
a=rtpmap:0 PCMU/8000
a=rtpmap:96 telephone-event/8000
a=fmtp:96 0-15
a=ptime:20
a=sendrecv

It's defiantly 96 and not 101

 

[Cardine]

Still messing around with this, it has something to do with the provider wanting out-of-band signalling and the 5000 supporting only in-band signalling... according to 5000 Support out of band does not work.... i thought this was RFC2833.....???

Working with a new provider and now DTMF works outbound but not inbound....


FUN FUN FUN....

 

[InspironXD]

I think it's a bug in the 5000.

By default the DTMF Encoding Setting is set to "G.711 Mu-Law" which I assume means inband but the SIP header still shows RFC2833 with DTMF Payload of 96.

If you change it to RFC2833 the payload stills stays at 96 but the ptime goes to 30.

Go figure.

My provider was able to manipulate the DTMF payload in their SBC so it's working fine for me.

 

[Cardine]

The first provider couldn't get DTMF working on outbound and now the 2nd provider is having troubles on inbound.....can someone remind me why i'm selling this system....???

 

[IrwinMFletcher]

You've only shown one side of the call. This is saying that the 5000 wants it's DTMF in RFC 4733 mode, under payload type 96.
What is the other side requesting?
What is the 500 sending?
What is the other end sending?

You need to remember that DTMF negotiation is asynchronous in the SIP world.

 

[InspironXD]

This is from the INVITE on all incoming calls:

c=IN IP4 X.X.X.X
t=0 0
m=audio 20478 RTP/AVP 18 0 101
a=rtpmap:18 G729/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:18 annexb=no
a=fmtp:101 0-15
a=ptime:20

 

[IrwinMFletcher]

Ok, so the outside wants 101 and the 5000 wants 96....so far so good. So when you hit a digit on a set off the 5000, what gets sent? 101 or 96?

 

[InspironXD]

Without changes in the SBC nothing.

 

[IrwinMFletcher]

So you mean no RFC packets ever get generated by the 5000?

If that's the case, then there is a failure in their logic (or most likely an omission of a case) that thinks that the RFC data needs to be synchronous. When it detects that, it sounds like it defaults to in-band.

Can the SBC just change the default payload type to be 96? and again, I'm not familiar with the 5000 interface, but can it not change it to 101?

 

[InspironXD]

Per tech support you can't change the payload type or ptime.

I know this was possible on their other models.

The ptime changes to 30 when the DTMF is changed from inband to rfc2833.

 

[IrwinMFletcher]

I know that the 3300 supports it, but that probably doesn't help you that much...

The best bet, until they offer that support on the 5000, would be to get the SBC to change to 96, that way you'll at least be still using RFC.