[Asterisk-biz] Modem Over IP: solutions ?

[trixter aka Bret McDanel]

On Sat, 2005-10-22 at 23:59 +0400, Jean-Michel Hiver wrote:
> Link latency is about 300ms with no more than 10ms jitter. If you have a 
> solution please let me know!

10ms is too high for any 'fast' modem connection and may be too high for
slower (sub 4800 bps) connections.  Modems rely on more exact timing
which is available due to the properties of the TDM network.  Jitter of
a few ms will break the newer protocols although it may be suitable
otherwise.

I am working to expand iaxmodem to support not just fax but also modem
data.  I currently dont have the time I would like and have done little
omre than look at the code and talk to Lee in a few emails, but that
should change soon.

What modem protocol is used?  

Keep in mind its way better to run iaxmodem on the asterisk server
itself over Zap channels as timing between iaxmodem and asterisk is very
critical.  


Now if he is switching to IP how is that accomplished?  If the device
itself is being modified to use IP why not send a packet or two instead
of modem data?  That would save bandwidth, cut response time, etc.  Or
was the plan to not modify the device instead just supply a small cheap
sip terminal? 

If the latter is the case then why not see if you are capable of running
everything needed on the sip terminal and send off a SIP IM or something
to a better equipped system?

Just trying to see if there is a better way, VoIP is not always the best
solution for a given problem, at least not right now.

-- 
Trixter http://www.0xdecafbad.com     Bret McDanel
UK +44 870 340 4605   Germany +49 801 777 555 3402
US +1 360 207 0479 or +1 516 687 5200
FreeWorldDialup: 635378
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