[cisco-voip] DTMF interworking on CUBE - asymmetric payloads

Tue Jul 19 16:28:25 EDT 2016

interesting - i wonder why that is not supported when it works.  doc error
or some legit technical issue ?

On Tue, Jul 19, 2016 at 3:44 PM, Anthony Holloway <
avholloway+cisco-voip at gmail.com> wrote:

> I do it to, but did you know that RTP-NTE to SIP-KPML is not supported on
> CUBE as of yet?
>
>
> http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/configuration/cube-book/dtmf-relay.html#concept_264617919921874995299551391601561__table_16E37E2F33CE4E0B836D2E5A809E7252
>
> On Mon, Jul 18, 2016 at 8:21 PM, Justin Steinberg <jsteinberg at gmail.com>
> wrote:
>
>> yes, CUBE can do RFC2833/NTP to a Telco and SIP-KPML to CUCM.   I do this
>> for calls that terminate on CCX IVR since CCX does not support RFC2833.
>> With only rtp-nte on the dialpeer from CUBE to CUCM, CUCM will invoke a
>> MTP.   Adding sip-kpml to the dial-peer will allow RTP directly from CUBE
>> to CCX without any MTP in the middle.
>>
>> On Mon, Jul 18, 2016 at 5:08 PM, Ed Leatherman <ealeatherman at gmail.com>
>> wrote:
>>
>>> Thanks Daniel, that helps a lot in understanding the feature. I'm
>>> curious if CUBE will also translate digits to KPML in this case if the leg
>>> to CUCM has that negotiated. Wish I had a lab built out for this :)
>>>
>>>
>>>
>>> On Mon, Jul 18, 2016 at 4:22 PM, Daniel Pagan <dpagan at fidelus.com>
>>> wrote:
>>>
>>>> Ed:
>>>>
>>>>
>>>>
>>>> I specifically worked with the dynamic payload option for a few cases
>>>> that came my way. Based on my findings, when a dynamic payload type (such
>>>> as 100/101/etc.) is received by CUBE, it will check if the next-hop
>>>> dial-peer has the asymmetric payload feature enabled and, if it is, will
>>>> pass the received payload type through to the next call-leg. Take a look at
>>>> my screen shot below. This was taken from some old notes where AT&T was the
>>>> customer’s carrier.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> The call flow above shows two call-legs, and *the arrows represent an
>>>> offer/answer exchange*.
>>>>
>>>>
>>>>
>>>> With asymmetric payload enabled on both call legs, the 100 offer from
>>>> ATT is passed to CUCM despite 101 being the default PT for NTE. In the SDP
>>>> answer from CUCM, we’re getting PT 101 -- since asymmetry is enabled on the
>>>> DP to ATT in this call flow, we pass the 101 through to ATT despite having
>>>> received PT 100.
>>>>
>>>>
>>>>
>>>> This results in asymmetry on our negotiated PT for each call-leg.
>>>>
>>>>
>>>>
>>>> *Let’s change it up a bit… A second example.*
>>>>
>>>> If asymmetry was disabled on the dial-peer to CUCM but enabled to ATT,
>>>> we would receive 100 PT from ATT, send 101 to CUCM, receive 101 from CUCM,
>>>> and send 101 to ATT. The resulting PTs would be symmetrical between CUBE
>>>> and CUCM, but asymmetrical between CUBE and ATT.
>>>>
>>>>
>>>>
>>>> See screenshot below for a third example:
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> This example shows asymmetric payload disabled on both call-legs using
>>>> the same call flow. CUBE receives PT of 100 from ATT -- the outbound
>>>> dialpeer has asymmetry disabled, so it transmits the PT specified for that
>>>> dial-peer (default 101 or any hardcoded dynamic PT) to CUCM. We then
>>>> receive 101 from CUCM and, since our inbound dial-peer has asymmetry
>>>> disabled, CUBE sends 100 to match the original PT it received. Asymmetry is
>>>> disabled so CUBE is not passing the received dynamic PT through to the
>>>> next-hop dial-peer - we have symmetry on both call legs for our NTE PT.
>>>>
>>>>
>>>>
>>>> Note that CUBE has no issues receiving one dynamic PT for NTE and
>>>> sending another (ex: receiving PT 100 and transmitting 101 for RTP-NTE) on
>>>> the same call leg.
>>>>
>>>>
>>>>
>>>> Hope this helps
>>>>
>>>>
>>>>
>>>> - Dan
>>>>
>>>> --------end attach---------
>>>>
>>>>
>>>>
>>>> *From:* cisco-voip [mailto:cisco-voip-bounces at puck.nether.net] *On
>>>> Behalf Of *Ed Leatherman
>>>> *Sent:* Monday, July 18, 2016 3:10 PM
>>>> *To:* Cisco VOIP <cisco-voip at puck.nether.net>
>>>> *Subject:* [cisco-voip] DTMF interworking on CUBE - asymmetric payloads
>>>>
>>>>
>>>>
>>>> I'm trying to get my head wrapped around some DTMF interworking
>>>>  features...
>>>>
>>>>
>>>>
>>>> I have this setup:
>>>>
>>>>
>>>>
>>>> UCM ------ CUBE ------- 3rd party system
>>>>
>>>>
>>>>
>>>> For both call legs through CUBE I'm advertising kpml and rtp-nte for
>>>> dtmf-relay
>>>>
>>>>
>>>>
>>>> The 3rd party sometimes sends me rtp payload type 101 for nte's, and no
>>>> kpml, and things work (as a bonus I observed CUBE correctly interworking
>>>> the nte's from the pbx into KPML, so uccx didn't break).
>>>>
>>>> Sometimes they send type 98 and no kpml, and things don't work.
>>>>
>>>>
>>>>
>>>> I'm trying to understand what is happening and what feature should fix
>>>> it (without breaking other things)
>>>>
>>>>
>>>>
>>>> Assumption:
>>>>
>>>> "dtmf-relay rtp-nte kpml" is telling CUBE to offer/accept rtp type 101
>>>> only for nte. I observe that CUBE negotiates KPML only for the associated
>>>> call leg back to UCM and doesn't bother with rtp-nte, so its just like any
>>>> other codec that CUBE doesn't care about.
>>>>
>>>>
>>>>
>>>> So.. if third party system ONLY sent me dtmf-relay with payload type
>>>> 98, could I just set the rtp payload type for this to 98 on the inbound
>>>> dial peer? would CUBE then correctly switch these up to 101 headed back to
>>>> UCM?
>>>>
>>>>
>>>>
>>>> How can I (or can I at all) make this work in my particular case were I
>>>> could receive both?
>>>>
>>>> I see "asymmetric payload dtmf" thrown about as a possible solution,
>>>> but I'm having trouble understanding what it actually does. It sounds like
>>>> it passes these payload types through CUBE, so UCM could be getting rtp
>>>> payload type 98 - it knows what to do with it? It seems like then CUBE
>>>> wouldn't be able to translate things to KPML this way...
>>>>
>>>>
>>>>
>>>> I'm reading
>>>> http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/configuration/cube-book/voi-dymc-payld-dtmf.html
>>>> but I guess I'm just not drinking enough coffee today (or too much) and I'm
>>>> not getting what exactly this command does.
>>>>
>>>>
>>>>
>>>> Anyone know how that asymmeteric command works?
>>>>
>>>>
>>>>
>>>> --
>>>>
>>>> Ed Leatherman
>>>>
>>>
>>>
>>>
>>> --
>>> Ed Leatherman
>>>
>>> _______________________________________________
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>>> cisco-voip at puck.nether.net
>>> https://puck.nether.net/mailman/listinfo/cisco-voip
>>>
>>>
>>
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>
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