[Asterisk-Dev] Re: Instability with H323

[Paul Cadach]

Hi,

> > Also, I don't think passing additional 10 kbps for 100 Mbit/s network is so
> > significant.
>
> Ahem.. Thats nice for you to only have to think about using Asterisk on
> Ethernet, however unfortunately some of us are out in the "real
> world" (substitute "third world" if you prefer) and don't have the luxury.
>
> Unfortunately, in my part of the world, "standard" cable internet costs approx
> $55/month for 128kbps/33kbps. This means for me (or my customers) to use VoIP
> at all from home the upload _must_ use less than 33kbps

I've told about local "clean" ethernet, not long-distance connections. Kazakhstan's Internet costs much higher than
your... :-)'

> For carrying calls on these types of links, I am sorry to say that my 6 year
> old "Clarent Media Gateway" is still an order of magnitude more efficient
> than Asterisk, as is any standard Cisco VoIP gateway.
> I have very high hopes for Asterisk however assuming Ethernet connections to
> VoIP gateways completely ignores probably 90% of VoIP users in the world.

One of most poppular usages of Asterisk is to provide local office soft-PBX to handle and distribute calls, provide
enhanced call support features like IVR, voicemail, etc. Usage of Asterisk as real VoIP switch IMHO is at "beta" stage
because requires many checks, additions and re-works to support, for example, jitter, etc. at ALL POSSIBLE VoIP
protocols (not only own IAX/IAX2).

For example, Asterisk isn't have support for configuring frames/packet on per-connection/per-protocol basis. Now it uses
_best_ common parameters (i.e. 20 or 30 ms per packet)...

> To repeat, 10kbps is ALOT of data to me, as it is exactly 30% of the entire
> upstream bandwidth from the greater percentage of my customers!

Any VoIP likes:
1) bandwidth (at least STABLE bandwidth, i.e. requires some sort of QoS);
2) low delays (usually not more than 150-200 ms);
3) predictable jitter (to provide stable buffering scheme).

Satellite links can't provide you with both of those parameters, so if you want to have high/commercial-quality VoIP
connection you need to thinking about changing your provider to someone who have "land" network (usually it's
phone/telecommunications companies provides "plain" telephony services).


WBR,
Paul.