[asterisk-biz] SIP providers
Trixter aka Bret McDanel
trixter at 0xdecafbad.com
Sun Jun 8 00:26:53 CDT 2008
On Sat, 2008-06-07 at 22:56 -0600, Lane Sullivan wrote:
> I am just wondering what provider everyone uses for their SIP trunking
> and their thoughts on who they use.
>
>
First, sip trunking has some standards in the works but almost no one
implements them. A side note before someone else jumps in, sip is just
signalling, rtp carries the media, and from its initial designs was
allowed to have trunking capabilities, but most rtp stacks disregard
this capability in favour of a much simplier method. In general its one
RTP port per RTP stream. This *can* be more efficient, depending on the
model used (ie if each rtp stream has its own thread its generally
better especially on a multi-cpu/core system, than if all of them go
into one port since only one cpu/core can service that one port).
Section 5.2 of RFC1889 (RTP) discusses some of the drawbacks of trying
to do trunking with that variant of RTP (the standards I mentioned are
elsewhere and use a slightly different method for delivery, basically
its an CRTP/RTP tunnel)
As a result not many do trunking with sip.
Unless you meant trunking in a different sense, and not the aggregation
of multiple RTP streams into one "connection" (yeah yeah udp doesnt do
connections).
Lastly, you may want to have an alternate signature if possible for lists.
Yours is quite long, and generally anything over just a few lines is
considered excessive. If you think about it, your signature is almost
850 bytes, that gets sent to thousands of people turning what seems to
be a simple email into a couple megs of traffic, for each email. And the
fact that its several times the size of your actual content makes it stand
out a little more I think.
>
--
Trixter http://www.0xdecafbad.com Bret McDanel
Belfast +44 28 9099 6461 US +1 516 687 5200
http://www.trxtel.com the phone company that pays you!
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