Fax and Telecom Testing Blog - All Comments

re: Version 3 of T.38 — It's Likely to be in Your Future

FM — Tue, 28 Apr 2009 22:31:55 GMT

You are correct that everyone wants it, but there are so few actual solutions available. I am totally amazed that Cisco hasn't released anything, and don't seem to have it on any public timeline, and I knew they were working on it before even your article was published.

re: Fax Transmission Power — More Is Not Always Better

... — Sat, 24 Jan 2009 02:42:03 GMT

Great site.

re: What is NSF... and why should I care?

Steve Underwood — Wed, 31 Dec 2008 19:59:00 GMT

A lot of business FAXing is between people is small closed groups. They may well all use the same model of FAX machine. In those situations I assume most FAXes exchange in a non-standard way, unless there is T.38 somewhere in the call path. I have no idea what percentage of FAX calls might fall into that category.

re: Fax Conformance vs. Interoperability — How do you strike the balance?

Steve Underwood — Wed, 31 Dec 2008 14:22:28 GMT

I was ranting about this very topic today (www.soft-switch.org/ramblings) and a quick Google in passing brought me here. Its good to see someone writing on these topics.

re: Fax Transmission Power — More Is Not Always Better

Steve Underwood — Wed, 31 Dec 2008 14:20:20 GMT

I don't think they clearly define the point at which that 0dB to -43dB range is to be measured. In the PCM network a V.29 or V.17 modem clips (no subtle distortion but hard clipping) above about -3dBm0. The V.29 spec says the modem should turn off below -26dB. The FAX specs say FAX should work down to -43dB, and don't actually say V.29 needs modification in this regard. Then again, there's a lot those specs don't say.

re: What is NSF... and why should I care?

Jonathan — Tue, 23 Dec 2008 17:29:43 GMT

Great explanation. Can you estimate the percentage of faxes sent via non-standard protocols? I would guess it is pretty small, considering the wide range of devices in the market.

Is that so? Do you know of other non-standard protocols that are published beside that of Adobe?