The answer is "it depends."  I have had success with a fax machine connected to a linksys PAP2T ATA and routing through vitelity as the SIP trunk provider (with Astlinux in-between).  I have had complete failure with an older Linksys/Sipura SPA-2002 and the same SIP trunk.

I have both a PAP2T and SPA-2002 connected to my system and the audio quality is noticeably better on the PAP2T.  In particular there is a lot of background hiss from the SPA-2002 that is not present on the PAP2T.  That may also suggest that the dynamic range of the SPA-2002 is not as strong as the PAP2T.  Both the background hiss and a compressed dynamic range would explain why analog fax does not work well.

In addition to good A to D conversion, which the PAP2T seems to handle well, you then have to deal with the characteristics of SIP/VoIP.  You may have to fiddle with settings like jitter buffer and echo cancelling and you want a high quality trunk provider.

Good luck.


On Thu, May 27, 2010 at 8:17 AM, Tom Chadwin <> wrote:
Slightly OT...

With an uncustomized 0.7.2 (1.4) on a net5501 with a berofix PRI, what is
the easiest way to attach an analogue fax which currently uses one DDI on
the UK PRI? Will an ATA work?




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