[olug] Level3 and fax modems over VOIP

Jaymz Ringler jringler at unitedtransport.net
Mon Apr 11 14:06:11 UTC 2005


I have a packet8 voip phone at home..   Using fax on their system is
spotty as well..  Apparently they are all trying to fix this as it's in
their faq about future support and trying to be the first to solve this
problem..

I haven't tried to use a dialup acct through it yet.. I don't think it
will work...



On Sun, 2005-04-10 at 20:22 -0500, K.J. Kirwan wrote:

> I didn't know this was a problem, so I'm glad you said something. 
> I hope others will be able to add some useful information. 
> 
> Using a modem (recent modems, 56k, even 33k, etc.) on VOIP I could 
> see maybe being a problem because they are designed to use as much 
> of the theoretical bandwidth of an analog voice line as possible. 
> Whereas VOIP is designed to simulate an analog phone line while 
> using as little bandwidth as possible. So I'll let that go for now. 
> 
> But the fax problem surprises me. I thought faxes were all running 
> 14400/bps max, and that seems pretty low by recent standards. 
> 
> It would be interesting to try a pair of US Robotics' so-called 
> "V.Everything" modems on VOIP.  Maybe test & review some networks? 
> 
> Have you tested what LightYear.net said? 
> What does your VOIP equipment do with faxes and modems if you 
> connect it all together in the same room on a private LAN? 
> 
> This sounds like it has more to do with latency and packet priority than 
> bandwidth.  Maybe analog modems and faxes are intolerant of varying 
> time delays since delay seldom changes on an analog line? 
> So vendors charge more for higher packet priority to fix the problem, 
> or say no, they don't support faxes/modems?  Of course, I suppose the 
> vendor might also say, "Hey, it's called VOIP, not MOIP or FOIP!"
> 
> It's an interesting problem, please keep us posted on this. 
> 
> K.J.
> 
> 
> Rob Townley wrote:
> > You may be aware that faxing or using a modem over a VOIP line
> > generally does not work, and if it does, it probably does not work
> > well.  Even Vonage does not work well.  I discussed this with
> > LightYear.net, ( a VOIP provider that provides Omaha telephone #s )
> > and they said the hardware they sell and the SIP protocol used both
> > are capable of faxing over VOIP, but that their provider Level3 does
> > not support it.
> > 
> > Can anybody confirm that this really is a problem with Level3?  If you
> > got faxing & modem communications to work, did you have to pay extra? 
> > Anybody know if Vonage uses LVLT.net?
> > 
> > p.s. I used iConnectHere.com because it was $8.95/month and after
> > several months could pretty much get single page faxes to work and
> > much later multiple page faxes, but it was not all that reliable.  I
> > decided it was worth the trouble.
> > 
> > p.s.s. I am a stockholder and needless to say i was very disappointed
> > that lvlt.net and level3.com were down some today!
> > _______________________________________________
> > OLUG mailing list
> > OLUG at olug.org
> > http://lists.olug.org/mailman/listinfo/olug
> > 
> 
> 
> 
> _______________________________________________
> OLUG mailing list
> OLUG at olug.org
> http://lists.olug.org/mailman/listinfo/olug



More information about the OLUG mailing list