testing dial up modem over VoIP

Is it possible to test a dial up modem connection using a VoIP phone? I'm thinking that it's not as I can't seem to get a modem in the house to handshake.

Thanks

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------------------------------------------- Chris Eilersen snipped-for-privacy@eilersens.com

Reply to
Chris Eilersen
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NO.

Reply to
Seeker

So IP telephony systems do support modems, but they dont use an IP phone - the speech compression system tends to scramble the signal.

If you had a phone set to do G.711 (which is 64k of data, maybe 80k or more with overhead) you may get somewhere, since that is the same digitisation used in a conventional TDM pbx - and your modem has to work with that....

Reply to
stephen

You can't use a conventional dial-up modem over any compressed VOIP line and even G.711 uncompressed is going to be a challenge unless you've got voice priority (802.1p/q) working end-to-end.

Reply to
Mitel Lurker <wdg

I couldn't even get a modem to work thru a Sipura 3000 going from the POTS port out the PSTN port. This is implimented in the Sipura as a VOIP connection between the two ports inside the box.

I've completely given up on being able to connect modems via VOIP.

Mike Schumann

Reply to
Mike Schumann

Yes it is possible, but the tricky part is keeping the voIP conenction solid enough. Be sure that you are running g711u law and not g729. That is the first point to start.

Reply to
BK80

Well there is also X-lite iLBC ..

oh and don't forget GSM

WHat I do not get is why there does not seem to be any hardware phones that support them .. beyond professional office phones like Snom..

(not snom supports GSM but no iLBC yet anyway)

Anyone know phones that support these two standard codec's .. I figure since snom is based on linux and is pretty much a open phone that they will support it before the otheres..

m.

Reply to
m

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