[asterisk-dev] Asterisk Media Architecture project

[Stefan Schmidt]

sorry this should be a private mail to david vossel. but i think its ok
on the list, cause these are things which belongs to all users ;)

best regards

stefan

Am 12.05.11 13:00, schrieb Stefan Schmidt:
> Hello david,
> 
> i have found an interesting problem with the media archeticture in asterisk.
> 
> if possible take a short look at issue 19281. in there is a sip invite
> message from a siemens hipath system which has two media descprition parts.
> 
> one with normal RTP and another with SRTP. the second with srtp is wrong
> cause there is no port number and a=sendrecv but by looking at this i
> found another problem.
> 
> i have talked with Oej about this and he also thinks that these two
> stream offers are simultanious, but valid in this way. But asterisk will
> overwrite the data from the first stream cause its the same type.
> 
> so in this case the siemens offers srtp and rtp as a fallback and cause
> this is rfc valid we should also honor this in asterisk. But this will
> not work.
> 
> the problem this user has is that asterisk will not support srtp for
> this peer but the fallback to the normal rtp will not work. i have
> allready write a patch for this but this doesnt solve the architecture
> issue with this.
> 
> do you allready hit this problem in your work, cause i think this leads
> to some questions which has to be answered.
> Like which stream should be prefered: secure, non secured, best /
> cheapest codec, first or random.... if there are multiple streams of the
> same type (audio + audio or video + video...)
> 
> thank you!
> 
> best regards
> 
> stefan
> 
> Am 08.12.10 17:46, schrieb David Vossel:
>> Howdy,
>>
>> I'm working on a long term project that involves completely reworking how media is handled in Asterisk.  I have spent the last month researching solutions for the problems in Asterisk's current media architecture and creating a high level design document outlining my approach to fix them.
>>
>> Here is a link to the design proposal on the new Asterisk wiki.
>> https://wiki.asterisk.org/wiki/display/AST/Media+Architecture+Proposal
>>
>> This document covers quite a bit of topics.  The best place to start reading to decide if this is something you are interested in or not is the "Project Requirements" section, but I'm going through out some requirement keywords for you below to help out.
>>
>> - SILK
>> - H.264
>> - Improved translation path generation to work with all media types
>> - Video transcoding
>> - Multiple Steams with translation paths
>> - No format bit field limits
>> - Renegotiation media after call setup
>> - Negotiating media formats containing attributes (Request video with the parameters you actually want)
>>
>> I need your feedback.  If any of this interests you then read the document, or at least the areas that concern you, and post your comments.  Please keep this discussion on the -dev list.
>>
>> Thanks!
>>
>> David Vossel
>> Digium, Inc. | Batman Developer, Open Source Software
>> 445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
>> Check us out at: www.digium.com & www.asterisk.org
>> The_Boy_Wonder in #asterisk-dev
>>
>>
> 
> 


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Stefan Schmidt
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