Re: [hylafax-users] Question about a modem

["Jay R. Ashworth" <jra@baylink.com>]

On Wed, Oct 24, 2001 at 05:37:52PM +0200, Giulio Orsero wrote:
> >> (is there any modem that works with VoIP
> >> lines??)
> >No.  You need to do special things to fit fax transmissions over VoIP
> >networks, because the codecs that are used to compress the voice Will
> >Not Work At All with a modem signal.  Except maybe at 300baud.

> Then I'm lucky, because my modem does fax at 14400 over VoIP :-)

No, you have a VoIP system with explicit fax bypass support.  This has
either a T. number ot a V. number, but I forget which.

> A cheap rockwell class1. Our VoIP stuff explicitly support FAX
> connection (but no data connection, no ppp), I think you tell it "this
> port will have a fax" or similar.

Yep.  And then it kicks in a separate modem on that port, and spoofs
the modem transmission, bypassing the VoIP codecs completely.

> However, I've another modem that does not work because it wants only 2
> wires phone cables, while the VoIP cable is 4 wires; this modem always
> "hears" RINGs on the line while there's none.

Henh?  I'm not aware of *anything* that's four-wire, except MultiTech
leased line analog modems...

> BTW the VoIP we use is a MultiTech, so they have experience in
> fax-modems.

This may explain it.  :-)

Cheers,
-- jra
-- 
Jay R. Ashworth                                                jra@baylink.com
Member of the Technical Staff     Baylink                             RFC 2100
The Suncoast Freenet         The Things I Think
Tampa Bay, Florida        http://baylink.pitas.com             +1 727 804 5015

   "Usenet: it's enough to make you loose your mind."
     -- me


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