no initial codec negotiation (SDP/SIP)? (cube and cucm 6.2)

[TinyLittleAdmin]

Hi community,

the last days this forum was a great help for me - so I thought - let's try it again We have some outgoing calls that just don't work. You can never hear a dial tone - the call doesn't get established. The provider told me it's simple: my phone system doesn't send "codec offers". So what happens is: the receiver tries to choose one, which than even gets blocked on my end.

I have set a package of codecs and use them on my dial peers like this:

voice class codec 1
 codec preference 1 g711alaw
 codec preference 2 g711ulaw
 codec preference 3 g729r8
 codec preference 4 g722-64
 codec preference 5 g722-56
 codec preference 6 g722-48

But it looks like I'm missing an active option either within cucm (I guess on the SIP config) or on the cube router. Maybe just a simple "provide codec offers" button....?

Any ideas?

Thanks in advance.

[b.winter]

Hi,

CUCM and CUBE work in "delayed-offer" mode by default.

So, they won't offer any SDP in their initial INVITE.

You can change this on CUBE with the command early-offer forced under the global sip config (voice service voip --> sip --> early-offer forced) or in the dial-peer config.

In CUCM, you would need to set the parameter Early offer support for voice and video calls to Best offert in the SIP profile, which is assigned to the SIP Trunk.

[TinyLittleAdmin]

Thanks b.winter,

I was close to this "early offer" thing... but.... I can't find these options - neither on cube (maybe IOS version too old - (C2800NM-SPSERVICESK9-M), Version 12.4(15)T5  ) nor in cucm (maybe also too old - 6.1.2.1002-1).

Hmm.....

[b.winter]

Both systems are way to old and years and years end of everything.

Why are you still using this old stuff?

[TinyLittleAdmin]

I could write a three pages answer to that - but for now - business...? (smiley)

[Scott Leport]

Hi, 

Sounds like you need new hardware! 

Can you try this on your CUBE:

voice service voip 
 sip
  early-offer forced 

The parameter in CUCM described in the SIP profile isn't there in CUCM version 6. It didn't come out till about version 8 and above so I believe. 

I think the only way you can force Early Offer from CUCM is to select Media Termination Point required on the SIP trunk, but it's not a great solution. It's another potential option though if stuck. 

[TinyLittleAdmin]

Hm.... do I have the chance to upgrade the firmware on the 2800 router (cube)? Will that give me the chance to use that "early offer" command? Or is there a limitation because of the hardware itself and there is no available upgrade the could fix it...?

Thanks to all for your quick responses....

[Scott Leport]

IOS for 2800 platform is no longer available, so no you can't upgrade. 

If you can't enter the commands I mentioned above, they're not available for your platform. 

As already pointed out, your hardware is end of everything (support, sale, life etc) so you're best to get that addressed by purchasing hardware which is in support. Best not to wait for your current hardware to break before you do so. 

[TinyLittleAdmin]

Any recommendations for a cisco router that should do the magic and work as a cube? I'd choose that way as a meantime fix. As I can't provide/setup a complete new phone system just within a few days ....

[b.winter]

If you are planning to do an upgrade of your infrastructure anyway, then definitely one of the current 4XXX ISRs.

Depending on the expected call volume, you need to choose which specific router platform you need.