[cisco-voip] CUCM6+E1 PRI A-law

Oleg Skomorokhov pocketapl at nm.ru
Thu Oct 29 15:52:29 EDT 2009


I've made sort of a test few minutes ago. I've unregistered the e1 pri
(mgcp) from CUCM and configured it with voip dial peer ( session target to
CUCM, added a h323 gateway instead mgcp gateway).

If i enable that dial-peer to use a voice-class codec with following
preferences:

1 g711alaw
2 g711ulaw
3 g729r8

The negotiated codec will be g711 U-LAW (funny).

If i enable the dial-peer to use only the g711alaw codec, it will be
negotiated (sh voice call status shows me that).



On Thu, Oct 29, 2009 at 10:36 PM, Ryan Ratliff <rratliff at cisco.com> wrote:

> Correct, there is no way to change that preference.  We have a knob for
> turning off g.722 but that's it.
>
> -Ryan
>
> On Oct 29, 2009, at 3:34 PM, Oleg Skomorokhov wrote:
>
> And looks like there's no way to reorder that preference.
> Well, thanks anyway.
>
> On Thu, Oct 29, 2009 at 10:08 PM, Ryan Ratliff <rratliff at cisco.com> wrote:
>
>> Not that I can tell.  CUCM makes no distinction between a-law and u-law
>> for g.711.  The only reason a phone would use one vs the other is if the
>> device the phone was talking to only advertised one and not the other.
>> Internally to CUCM there is a preference among codecs that use the same
>> bandwidth.  For the 64kbps codecs this preference is g.722, g.711u, g.711a.
>>
>>  -Ryan
>>
>> On Oct 29, 2009, at 2:59 PM, Oleg Skomorokhov wrote:
>>
>> it's set to a-law, but no luck.
>>
>> but forget the pri, is there a way to get intracluster calls negotiate 711
>> a-law ? i mean between 2 nearby ip phones.
>>
>> On Thu, Oct 29, 2009 at 9:41 PM, Ryan Ratliff <rratliff at cisco.com> wrote:
>>
>>> What is set for the PCM Type in the CCMAdmin web page for the PRI?
>>>
>>> That's the only place I can see where you can set a-law vs u-law.
>>>
>>>  -Ryan
>>>
>>> On Oct 29, 2009, at 2:36 PM, Oleg Skomorokhov wrote:
>>>
>>> There are some problems when talking with TELCO's support. some cracking
>>> and knocking sounds. No slips or other errors on E1 present.
>>>
>>> But mostly, it's just annoying me. Why should i use u-law in europe, if
>>> it was designed for US?
>>>
>>> So, even if we forget the E1 PRI, how to make the INTRAcluster calls to
>>> negotiate g711 A-law codec?..
>>>
>>> On Thu, Oct 29, 2009 at 9:31 PM, Ryan Ratliff <rratliff at cisco.com>wrote:
>>>
>>>> The compand type on your POTS leg has nothing to do with the codec or
>>>> compand type on the voip leg.
>>>>
>>>> Is this causing any problems or just something you noticed?
>>>>
>>>>  -Ryan
>>>>
>>>> On Oct 29, 2009, at 2:20 PM, Oleg Skomorokhov wrote:
>>>>
>>>> Hello all.
>>>>
>>>> I've got a e1 pri line in my office, terminating by cisco 2821. The
>>>> compand type for E1 (Europe) is A-law, and show voice port 0/0/0:15 also
>>>> tells me that.
>>>> E1 is registered via mgcp, and i also see the compand type A-law in
>>>> options there.
>>>>
>>>> When i press the question button twice during the pstn call, the
>>>> negotiated codec is u-law.
>>>>
>>>> The default codec in Region is "G711" (no option for a-law or u-law)
>>>>
>>>> Is there such an option in CUCM to change the default modulation type
>>>> for g711 codec?
>>>>
>>>> Thank you.
>>>>  _______________________________________________
>>>> cisco-voip mailing list
>>>> cisco-voip at puck.nether.net
>>>> https://puck.nether.net/mailman/listinfo/cisco-voip
>>>>
>>>>
>>> _______________________________________________
>>> cisco-voip mailing list
>>> cisco-voip at puck.nether.net
>>> https://puck.nether.net/mailman/listinfo/cisco-voip
>>>
>>>
>>
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://puck.nether.net/pipermail/cisco-voip/attachments/20091029/f8c08c55/attachment.html>


More information about the cisco-voip mailing list