[asterisk-dev] Native Bridging: terminology

[Klaus Darilion]

Am 18.03.2010 18:50, schrieb Russell Bryant:
> On 03/18/2010 10:25 AM, Mark Michelson wrote:
>> Klaus Darilion wrote:
>>> Hi!
>>>
>>> What is the exact meaning of "native bridging"? For example I know with
>>> DAHDI it means direct bridging on the hardware. But what about from one
>>> DAHDI interface card to another DAHDI card? Are there some optimizations
>>> that the audio stays within the kernel module or is it always send via
>>> Asterisk's core?
>>>
>>> Or in case of a SIP-to-SIP call with canreinvite=no. Will there be some
>>> optimizations that audio stays within the rtp module or will it be sent
>>> via Asterisk's core? If there are such optimizations - is this called
>>> direct bridging or is direct bridging the RTP exchange between clients
>>> directly using canreinvite=yes (which I would not call direct bridging
>>> but "offload" or "bypass")? Or is this the "external native bridge"?
>>>
>>> thanks
>>> klaus
>>>
>>
>> The term "native bridge" is a bit overloaded in Asterisk. On the surface, it
>> simply means that the two legs of a call have the same channel->tech->bridge
>> function.
>>
>> I can't speak for DAHDI, but within SIP, native bridging has two subcategories.
>> One, typically referred to as "SIP native bridging" is used when reINVITEs are
>> enabled. The endpoints send their media directly to one another. The other
>> subcategory is called "Packet 2 Packet" or "P2P" bridging. If reINVITEs are not
>> enabled, but there are also no features that require the Asterisk core to be in
>> the voice path, then the bridging will be done at the RTP layer of Asterisk.
>
> There is a section on the architectural concept of bridging (including
> native bridging) in include/asterisk/doxygen/architecture.h.  If anyone
> would like to help expand upon this text, I would appreciate it.  :-)

That's were i found the term "external native bridge" :-)

thanks
klaus