[asterisk-dev] [Regression issue] Garbage RTP data with Asterisk

[Matthew Jordan]

On Sun, Feb 8, 2015 at 4:24 AM, Hans Petter Selasky <hps at selasky.org> wrote:
> On 02/08/15 08:45, Hans Petter Selasky wrote:
>>
>> On 02/08/15 08:44, Hans Petter Selasky wrote:
>>>
>>> Hi,
>>>
>>>  From time to time the Asterisk RTP engine outputs some 4-byte ULAW
>>> packets (even when the data stream is ALAW), making me believe that the
>>> packets don't come from the source channel driver. The content of the
>>> packets is constant: 0x02 0x8A 0x02 0x80
>>>
>>> These cause pops/clicks at the receiver. How can the source of these
>>> packets be found? Is there perhaps a race in Asterisk?
>>>
>>> Has anyone seen this issue before. I have a very old installation of
>>> Asterisk ~v1.6 which does not exhibit this issue.
>>>
>>> --HPS
>>>
>>
>> Forgot to mention:
>>
>> Seen with Asterisk 1.8 and 11
>>
>> --HPS
>>
>>
>
> Hi,
>
> Some further investigation reveals that the payload type is "0" instead of
> "101" for DTMF.
>
> The 4 bytes are a DMTF packet and apparently this function has failed:
>
>>         /* Grab the payload that they expect the RFC2833 packet to be
>> received in */
>>         payload =
>> ast_rtp_codecs_payload_code(ast_rtp_instance_get_codecs(instance), 0,
>> AST_RTP_DTMF);
>

What is the DTMF payload code negotiated by both sides?

-- 
Matthew Jordan
Digium, Inc. | Engineering Manager
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
Check us out at: http://digium.com & http://asterisk.org