Re: flexfax: Large number of errors with Hylafax and ZyXEL Omni modem

[Robert Colquhoun <rjc@trump.net.au>]

Hi Shuvam,
It's hard to make sense of the numbers below(at least for me), i've got a
small script "errorstats" which parses xferlog for errors grouping by type.

Download from http://www.trump.net.au/~rjc/hylafax/

For some numbers - we are using USR Couriers for sending and receiving.
>From the statistics gathered by my errorstats script no particular modem
error is occuring more than 20 times per thousand fax sent.
Roughly:
	Transmit Phase B ~ 13/1000 (The modems are operating in Class 2.0)
	Unknown Modem Problem ~ 17/1000
	T1 Timeout ~ 6/1000
	DCS Errors ~ 7/1000
	EOP Errors ~4/1000
A number of other errors each less than 3 per 1000 fax sent

The negative retrain problem is occuring occasionally, it is worse than
other fax errors in that you always get a complaint from the other end
whereas with the other modems errors fail silently.

I've looked quickly into the source code and i think i can see where to
change the code to stop the retransmit _but_ i am not very keen to do this.
Firstly i am not sure this is the right thing to do and i dont currently
have a good test setup to check whether this is done correctly.

If i was in your situation i would 1) get some accurate data on how many
calls are failing and why 2) double check your configuration 3) get the
telephone company to check all your phone lines.

- Robert

At 07:53 2/04/98 +0530, Shuvam Misra wrote:
>This is in continuation to earlier mails from myself and others on this
>topic. I'm running a TPC cell using Linux, Hylafax 4.0pl2, and a ZyXEL
>Omni O288S, as mentioned before. This is the statistical count of the
>Hylafax transfer figures for the last day:
>
>     52	0
>     39	2
>      6	3
>     13	4
>      1	5
>      1	6
>      2	7
>      1	9
>      1	10
>      1	11
>      1	12
>      1	13
>      1	14

>
>The first field is count or frequency, and the second is the number of
>people who sent a total number of pages as shown. So "52 0" means that
>52 people queued one or more jobs and could send only 0 pages. The
>second line is "39 2" which means that 39 people sent a total of 2 pages
>each. (This is the minimum length of most TPC jobs, because they have
>a cover page, and a short message page after that. This means that 39
>people sent one job each.) And so on.
>
>The total is 121 people, who have tried sending faxes out. Out of them
>52 people couldn't send out anything at all, as we can see. This is
>unacceptable by any standards, I would think. Harald Pollack has said that
>any public fax broadcaster will encounter about 40% failures. Another
>gentleman has been using Multitech modems and has reported 5 to 10%
>failures only. I am reporting about 45% faxes failed, which means perhaps
>60 to 80% of alls calls made, failing. (This is because each fax fails
>only after it has made several attempts to go through.)
>
>Another figure shows that 242 pages were transmitted successfully,
>but 313 error-calls were recorded. These errors exclude the ones where
>carrier couldn't be established. This means that each of these 313 calls
>were completed at the Telco level, and so will be billed to me. Is this
>typical? I am sure all TPC operators who use Hylafax will be getting
>their daily report from "faxcron". Can they send me a five line email
>just cutting out the day's "Total" line from yesterday's report, together
>with a line giving which area they operate in?
>
>Most of us run TPC as a voluntary service. We need to cut wasteful
>expenditure.  We use Hylafax, and we need the Hylafax community to
>come together to figure out whether there is indeed any problem in
>the software which might be increasing errors, as Harald's and others'
>mails have hinted. I have not seen much discussion on the Hylafax
>mailing lists about these fundamental aspects of its behaviour; most of
>the discussion revolves around new setup problems, cover pages, and the
>like, which are important but are not of use in this specific case.
>
>Is Sam Leffler still active on this list or with this software? Is Matt
>Apitz or David Woolley or anyone else in a position to take up these
>issues and bring down the errors, specially with ZyXEL modems? One set
>of ZyXEL users who don't use Hylafax, swear by its fax implementation.
>Should all Hylafax users then switch out of ZyXEL to Multitech? Or
>should all TPC operators switch out of Hylafax?
>
>Hoping for more responses on this list,
>
>regards,
>Shuvam
>