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Mgetty+Sendfax with Vgetty Extensions (FAQ)

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Archive-name: fax-faq/mgetty+sendfax+vgetty
Last-modified: 1998/03/12
URL: http://www.webforum.de/mgetty-faq.txt
Maintainer: Klaus Lichtenwalder <Lichtenwalder@ACM.org>

See reader questions & answers on this topic! - Help others by sharing your knowledge
			  ``mgetty+sendfax''
		Answers to Frequently-Asked Questions
       regarding Gert Doering's Fax-enabled getty replacement,
       with Klaus Weidner and Marc Eberhard's voice extensions

			 Klaus Lichtenwalder
		        Lichtenwalder@ACM.org

        Posted by: Chris Lewis, clewis@ferret.ocunix.on.ca


Subject: Introduction This document attempts to answer the most frequently asked questions about mgetty+sendfax/vgetty, Gert Doering's fax-enabled getty replacement with Klaus Weidner's and Marc Eberhard's voice processing extensions. The official release of mgetty is now (at least) 1.0. Gert adopted the numbering scheme of the Linux kernel, with even release numbers (1.0, 1.2,...) being production version and uneven numbers being development versions. Pls note that in 1.0 there's no vgetty support as that is being revamped. If you need voice, you have to go for older versions or, far better, for the newer development tree. Subject: Japanese Version I'm glad I can announce a Japanese Version made by chie nakatani <jeanne@mbox.kyoto-inet.or.jp>. You can find it at <URL:http://epsenewsc.gee.kyoto-u.ac.jp/JF/JF-ftp/euc/mgetty_j.euc> Subject: Legalese This document is copyrighted by the FAQ Maintainer, K.Lichtenwalder. It may not be reproduced in part or in full without the written consent of the FAQ Maintainer.
Subject: Table of Contents Part I: "Deciding whether to use it" questions What is it? What does it look like when it runs? What do I need to use mgetty+sendfax/vgetty? What other software do I need? What terms cover my use of mgetty+sendfax/vgetty? Where can I get mgetty+sendfax? How can I integrate it into an office environment? What's going on with those Class 1 modems? What modems are recommended? Where is the list archived? Part 2: Other questions How can I contact mgetty/vgetty users and developers? What image file formats can sendfax send? Why doesn't mgetty accept other file formats besides G3? Why doesn't mgetty use the modem's autoanswer capabilities? Why mgetty ignores /dev/tty* dialin, /dev/cua* dialout conventions: Troubleshooting questions & answers Programs generating "invalid" Postscript that can't converted to the G3 format for sendfax My ZyXEL doesn't work right after a ROM upgrade: What's wrong? When is mgetty actually running? (i.e. what can mgetty control?) The user's shell doesn't get killed after the line drops AutoPPP appears in "who" listing Things to think of if using AutoPPP, or, as you might call it, ppp connections Part 3: Compatibility Issues Suspicious fax machines Part 4: Compiling, installing and using vgetty Compiling vgetty US Robotics voice format converter --------------------------- Subject: Part I: "Deciding whether to use it" questions
Subject: What is it? From: steve@work.bellingham.wa.us (Steve Work) Mgetty+sendfax is a collection of programs to send and receive faxes in a unix environment using a class 2.0 or 2 (they're different) faxmodem. vgetty is an extension to mgetty, distributed with it, that implements incoming voice call handling for certain voice-capable modems, with new ones added regularly, if specs are available. More specifically, the program `mgetty' allows you to use a class 2.0 or 2 fax modem for receiving faxes and handling external logins without interfering with outgoing calls. `sendfax' is a standalone program which sends fax files. `vgetty' is an extended version of mgetty that can answer the telephone like an answering machine and record a voice-mail message (if it finds one), or perform `mgetty's fax or data call handling otherwise. The mgetty+sendfax distribution includes vgetty and a good-sized gob of utility programs that help you manage faxes and voice messages.
Subject: What does it look like when it runs? From: steve@work.bellingham.wa.us (Steven Work) and the distribution CC: clewis@ferret.ocunix.on.ca (Chris Lewis) Like a smarter `getty'. getty is the program that manages the first step of the login procedure on a Unix computer; when used with a modem, it watches for an incoming call and (ordinarily) prints the "login:" prompt (and reads the username, and passes off to "login"). Unlike traditional versions of getty or uugetty, which will put a modem into auto-answer mode, mgetty does not. When an incoming call occurs, mgetty sees the "RING"s when they occur. When they do occur, mgetty tells the modem to answer, and the modem will tell mgetty what kind of connection happens. If it is FAX, mgetty will receive the FAX. If data, mgetty prompts for a userid, then hands the open line off to login for a normal data login. Note that it's the modem's job to distinguish a FAX call from a data call. Not all fax modems can do this, and if yours _can't_ there is no way for mgetty to do this for it. mgetty can be used with modems that cannot distinguish a fax call from a data call, but you must tell it ahead of time what type of call to expect. mgetty is also configurable to select programs other than login for special connections (eg: uucico, fido or other programs) depending on the login userid. mgetty also supports caller-id and can deny connections based on originating telephone number. vgetty is an extension to mgetty that works with voice-capable modems to provide additional call-handling capabilities. When the modem reports a RING, vgetty has the modem pick up the line and play a voice message (the greeting). If the modem detects a data or fax calling tone, it reports this back to vgetty with special codes (DLE-sequences) which causes vgetty to switch to either mode. Else voice mode is used. If instead the modem hears nothing following the greeting (a certain level of silence that continues for a certain number of seconds) it assumes the caller is a data modem and attempts a data connection. vgetty implements the normal answering-machine functions of remote message playback as well; its operation is driven from shell scripts, so you can extend it to a full voice-mail jail if you wish. (This description of voice modem behavior applies to the ZyXELs; I [steve@work.bellingham.wa.us] assume other voice modems are similar.) For an example on how a voice mail system looks like, there is the voice_mail.sh script in voice/scripts from Marc Schaefer. Since the voice shell is independent of the real modem hardware, it works on all supported modems, not just ZyXELs. The hardware drivers hide the modem specific stuff, so that the voice shell can provide a general interface that is completely modem independant. Of course the reliability of the whole systems relies on the reliability of the used voice modem. And there are quite notably differences between different modems. vgetty is intended for people who want to share a phone line for data and voice use, with the main focus being voice calls. It is *NOT* intended for a dialup system that occasionally gets a voice call, since some modems are confused by hearing a recorded voice message and won't connect. If you have distinctive ring, you still can have one line, but vgetty can detect the type of the call from the RING message and switch directly to data/fax mode. In countries where distinctive ring is supported, you can have dialup and voice on the same line without problems. Voice extensions were originally written by Klaus Weidner (klaus@snarc.greenie.muc.de) but are now maintained by Marc Eberhard (Marc.Eberhard@Uni-Duesseldorf.DE). Direct questions about them to that address. More from the distribution (some edits): This is what you can do with `sendfax' if you have a standard class 2.0 or 2 fax modem: * send faxes directly or using shell scripts (easily integrated into other applications). * do "fax polling", this means you can call the weather station and get them to send you a fax containing the current weather map. (Not all modem manufacturers implement this feature in their modems!) * create a "fax queue", outgoing faxes get sent automatically, the user is informed by mail about the result. `mgetty' allows you to use a single modem line for receiving calls and dialing out. * `mgetty' knows about "smart" modems, and will make sure that the modem is always in a defined state (specific modem initialization possible) * Incoming calls are answered manually (`RING' -> `ATA' -> `CONNECT') instead of using auto-answer (`ATS0=1'), this way the modem won't pick up the phone when the machine is down or logins are not allowed. * mgetty completely replaces getty and/or uugetty. Like uugetty, supports lock files in a fashion compatible with almost all known versions of UUCP (HDB/BNU, SVR4, V7, Taylor in various flavours). uugetty has some features mgetty doesn't support; see "How does mgetty differ from uugetty?" below. * mgetty supports System V style gettydefs terminal configurations. * mgetty can receive class 2 faxes (if your modem supports it). * mgetty knows about incoming FidoNet calls. * mgetty has extensive logging / debugging features * do "fax poll sending", that is, you can setup your machine as fax poll server, to send some fax pages to "fax poll" callers. (Send informations about your system, the current wheather map, ...). Be warned, even less modems support this feature. * mgetty can selectively refuse calls based upon CallerID, if your modem supports it, and you're subscribed to the service. CallerID is also logged. * mgetty has facilities to allow you to refuse incoming FAXes when available disk space is low. * mgetty knows about incoming PPP calls, and can hand them off to the PPP-daemon, without requiring a login/password sequence. This feature is also known as AutoPPP vgetty inherits all of mgettys features, and offers some additional ones: * behaves like a normal answering machine for human callers * automatic fax reception when a T.30 calling tone is detected * If the caller isn't a human or fax, a data connect is attempted, if this is successful, the caller will get a normal login * does not interfere with dialouts * remote playback of messages via a DTMF code * toll saver -- if there are new messages, pick up the phone earlier, this way you can hang up in time to avoid a useless call * message light - the autoanswer LED of your modem (if it has one) is turned on if there are new messages * easy playback - on some modems, you can play back the new messages just by pressing DATA/VOICE * using a speech synthesizer is possible - add the date and time to messages (not included by default). The scripts show how to use a speech synthesizer like rsynth, but it is not included in the package. To use this feature, you need a voice modem for that; a converter from the pvf format to the rmd (raw modem data) format exists. This is not true for all supported modems. * voice conversion utilities - play messages on /dev/audio (Not for all supported modems, some voice modems use a proprietary format)
Subject: What do I need to use mgetty+sendfax/vgetty? From: steve@work.bellingham.wa.us (Steve Work), and distribution CC: clewis@ferret.ocunix.on.ca (Chris Lewis) Several things. A computer running some (most) variants of the Unix operating system. (The operating system must support termio.h or termios.h; this generally rules out "pure BSD" systems.) For support of dial-in data connections (a la "getty"), you need a modem (probably one somewhat compatable with the H*yes "AT" command set). For sending and receiving faxes, you need a modem that understands the Class 2 (or 2.0) fax command set. For voice processing, you need a modem that is capable of doing voice. Vgetty currently supports Dolphin, Dr. Neuhaus Cybermod, Elsa, IS 101 compatible, Rockwell, Sierra, US Robotics and all ZyXEL modems. The Cirrus Logic, ISDN4Linux and UMC drivers are basically working, but they need to be updated to the new internal interface between the generic vgetty parts and the hardware dirver. This change was necessary to be strictly ANSI C compatible. Vgetty now compiles with gcc -Wall -pedantic without a warning. Mgetty has been successfully installed and run on at least the following systems, probably more by the time you read this list: SCO Unix 3.2.1 (ODT 1.0) (very well tested) SCO Unix 3.2.4 (ODT 2.0 + 3.0) (very well tested) SCO Open Server 5.0 (Gert uses it ...) Linux 0.99pl1 .. 2.1 (very well tested) ISC Unix 3.0 (tested) SVR4 Unix (well tested) AT&T 3B1 3.51m (well tested) HP-UX 8.x (well tested) AIX 3.2.5, 4.1.4, 4.2 (mgetty, not vgetty) SunOS 4.1.x (well tested) SunOS 5.x (at least with USR 33.6 Misha Pavlov <oj@interport.net>) NetBSD / FreeBSD (works) BSDI v1.1 (under work, not done -- greg@wwa.com) It should be possible to run mgetty on any other Unix with `termio.h' or `termios.h'. For best results, `select(S)' or `poll(S)' are recommended, but there's a workaround. (Warning: for Unix SVR3.1 or earlier, *do not use poll()*, it will not work on tty devices.) Up to now, it has been successfully used with at least the following modems, and probably more: Here's a short list of often used modems. For an up to date list check with doc/modems.db from the distribution: * Aceex 1496 * Boca V.32bis * Creatix LC 288 FC * Practical Peripherals PM14400FXMT * TKR Terbo Line * U.S. Robotics Courier V.34 Fax * U.S. Robotics Sportster V.34 28.800 Fax Modem * Zoltrix Platinum Series 14.4 * ZyXEL 1496E+, always recommended Mgetty *should* work with all class 2 faxmodems. Maybe the DC2 character sent at the beginning of a page by `faxrec.c' must be changed to XON, for old class 2 modems (implementing very old drafts of the standard). Unfortunately, each class 2 modem can be a tiny bit different. Early USR fax modems did a bad job of conforming to the Class 2.0 (and maybe Class 2) operating standards. Reports are that current USR modems (Sportster and Courier) work without excuses.
Subject: What other software do I need? From: clewis@ferret.ocunix.on.ca (Chris Lewis) CC: gert@greenie.muc.de (Gert Doering) For data only, no other software is needed. mgetty itself can only send or receive G3 (raster) format. However, the distribution includes tools to convert raw G3 files to or from the format used by "pbmplus", the Portable Bitmap Toolkit. The pbmplus formats support (or are supported by) most raster-image programs and file formats generally used in the Unix world. pbmplus is available at this URL (among others): ftp://sunsite.unc.edu/pub/X11/contrib/pbmplus10dec91.tar The mgetty+sendfax distribution contains a patch to fix pbmplus's broken pbmtog3 converter -- using the unpatched pbmtog3 can cause errors during transmission. GhostScript, the free Postscript page description language interpreter, can convert PostScript to G3. Ghostscript is available at this URL (among others): ftp://sunsite.unc.edu/pub/gnu/applications/ (also check out patch files in same directory.) Hp2pbm, available from ftp:// ??, can convert text and PCL (HP Laserjet language) to G3 or PBM. It also contains programs for converting PBM to PostScript, PCL and Epson printers. PBMPLUS has converters from most existing raster formats or ASCII to PBM, and from PBM to most raster formats. You'd use the pbm2g3 and g32pbm utilities in mgetty to convert between PBM and G3. In essence, you can run with hp2pbm or PBMPLUS alone. With GhostScript, you also need PBMPLUS or hp2pbm to convert ASCII (used for page headers etc.) to G3. Mgetty+sendfax includes some voice processing utilities in the voice/ subdirectory. These tools (pvftools) can convert ZyXEL, Rockwell and ISDN4Linux voice formats. Other formats are coming. People reported success in translating GSM encoded voice formats, so support for that will also be added in the future. This means that vgetty currently supports the three above and support for more modems is planned.
Subject: What terms cover my use of mgetty+sendfax/vgetty? >From the distribution: "The mgetty+sendfax package is Copyright (c) 1993 Gert Doering. You are permitted to do anything you want with this program - redistribute it, use parts of the code in your own programs, ..., but you have to give me credit - do not remove my name. "If the program works for you, and you want to honour my efforts, you are invited to donate as much as you want. "If you make money with mgetty, I want a share. What I mean by that is: it's perfectly OK with me to get paid for mgetty installation or support, but if you want to actually sell mgetty, or pack mgetty with a modem and sell it as "unix fax package", contact me first. "*WARNING:* This package is still BETA software. Use it at your own risk, there is *no* warranty. If it erases all the data on your hard disk, damages your hardware, or kills your dog, that is entirely your problem. Anyway, the program works for me and quite a lot of other people." Marc put the voice part under the GPL. To avoid misunderstandings, Gert decided to not include the GPL text into the distribution, though. The copyright for the voice stuff is GPL.
Subject: Where can I get mgetty+sendfax? The home page is at http://www.leo.org/~doering/mgetty/ The official release sites are these URLs: ftp://ftp.leo.org/pub/comp/networking/communication/modem/ ftp://sunsite.unc.edu/pub/Linux/system/Serial/ ftp://tsx-11.mit.edu/pub/linux/sources/usr.bin/... (or so) ftp://linux.nrao.edu/pub/packages/mgetty+sendfax/
Subject: How can I integrate it into an office environment? From: Klaus Lichtenwalder <Lichtenwalder@ACM.org> and the mgetty dist. With mgetty, you get a subdirectory called frontends/. There are a lot of more or less documented programs for viewing/printing/organizing received faxes, for entering them into the queue from all kinds of different programs.
Subject: What's going on with those Class 1 modems? From: Klaus Lichtenwalder <Lichtenwalder@ACM.org>, modifying comments from Gert Doering While Class 2 and Class 2.0 modems do most of the dirty work themselves, clever modem manufacturers seem to drift toward implementing only class 1 fax modes. Probably so they can use smaller proms while also integrating voice functionality. Well, they want to see $$$, too.. The bad thing with Class 1 is, the modem expects all the dirty work to be done by the host computer. After all, why did you buy a Pentium II 300MHz? Just for hitting on a few keys from time to time? So you have a very fast cpu and there should be no problem to do something every n ms? Right? Wrong! Most of the Unix systems out there don't have realtime extensions (this *is* a real time job, after all), and if they have, there's no real standard to these extensions, so generally it's not possible to maintain that strain. Windows knows how to use class 1 modems? Yeah, sure, the multitasking is quite different, you can quite easily exclude other processes from running, because you just want to have that high priority process. And if you insist in doing some other time consuming tasks, your fax might no be very readable... So, so much prosa for this situation, you still might see some class 1 support in the near future. Just hang on and in the meantime, boycott modem manufacturers who only support class 1 modes.
Subject: What modems are recommended? From: Gert Doering <gert@greenie.muc.de> and the List ---------------------------------------------------- MODEM Recommendations for use with mgetty/vgetty ------------------------------------------------ What modem to recommend depends on your needs. There are very few modems that handle fax + data + voice perfectly, but quite a number that are well suited for two of the categories, and less good (or sometimes not at all) for the third. For Fax+Data: * USR Courier V.34/X.2 (no voice) For FAX+Voice: * ZyXEL 1496 (data only up to 19200, but best fax implementation) For Data+Voice: * USR Sportster VI series (fax implementation is VERY bad) For FAX+DATA+Voice * ZyXEL 2864 * MultiTech MT2834ZDXv * ELSA MicroLink TQV series (fax is not perfect, but works ok) Last updated: February 1998
Subject: Where is the list archived? From: Gert Doering <gert@greenie.muc.de> A pointer to the archive as well as lots of other documentation can be found at <URL:http://www.leo.org/~doering/mgetty>. The archive itself can be found at <URL:http://eli.wariat.org/mgarc/index.html>
Subject: Part 2: Other questions
Subject: How can I contact mgetty/vgetty users and developers? From: ezmlm at crynwr A mailing list exists. Due to its international character, the only supported language on this list is *English*, though it's gated to some local newsgroups, de.alt.comm.mgetty for example. To subscribe to the list, send mail to mgetty-subscribe@crynwr.com, to unsubscribe, send a mail to mgetty-unsubscribe@crynwr.com, NOT to mgetty@muc.de. If you want to specify a different e-mail address for your subscribtion than the address you send your subscribe request, send it to mgetty-subscribe-<your e-mail address with @ replaced by =>@crynwr.com. This address gets checked by sending a confirmation message. Example (from mgetty-help@crynwr.com): to specify God@heaven.af.mil as your subscription address, send mail to <mgetty-subscribe-God=heaven.af.mil@crynwr.com>. I'll send a confirmation message to that address; when you receive that message, simply reply to it to complete your subscription. The volume on mgetty@muc.de varies from one or two messages a week to ten or so a day, depending on development activity. If you have questions because of a misbehaving mgetty or vgetty, be sure to include the relevant parts of your log file, usually obtained with a loglevel of 6 The default location of these log files is /tmp/ for mgetty and /var/log for vgetty.
Subject: What image file formats can sendfax send? From: gert@greenie.muc.de (Gert Doering) Fax input format: raw G3 data (according to CCITT standard T.4, 1-dimensionally compressed). Can be created by GhostScript's "dfaxhigh" or "dfaxlow" drivers (they will create raw G3 data with a 64 byte header, that sendfax + g3cat + g32pbm will recognize and skip) or by the "pbm2g3" program. Warning: the pbmtog3 program from the "pbmplus" distribution does *not* create valid G3 data according to T.4, to be precise, the lines are shorter than 1728 pixels and the leading EOL code is missing. To fix it, use the patch that is provided in "patches/pbmtog3.p1". Even better, use my own utility. (The patch is *NOT* needed for my pbm2g3 program!). Use of a unpatched pbmtog3 will most likely cause +FHNG:50 or +FHNG:54 error codes. Do not use "tiff-G3" data as input. Though the data itself is G3 encoded, it's wrapped into a complex layer of TIFF headers that would require non-trivial parsing that's simply not needed for sendfax. Faxing a TIFF file will result in a warning message from sendfax, and, most likely, in a failed transmission. Fax output format: The files that mgetty places into FAX_SPOOL_IN are in the same format as the files that sendfax wants to send, raw G3 data as of CCITT T.4. To convert them to "pbm", use the g32pbm program. To convert them to X-Windows xwd format, use the "contrib/g3toxwd" program. If the files are received without transmission errors, it is possibly to send received fax files without any additional conversion. Since some modems insert filling zero-bits, a run through "g3cat" is recommended anyway, this will remove any surplus stuff, and clean up garbled lines.
Subject: Why doesn't mgetty accept other file formats besides G3? Why does mgetty only send raw G3 fax files, instead of converting arbitrary image files (like TIFF) on the fly? >From Chris Lewis: "As I understand it, in addition to its own formats, TIFF can encapsulate some number of other formats. Put another way, TIFF is, at least to some extent, simply a way of getting magic numbers into other formats so that TIFF-capable converters can handle multiple formats transparently. "Yes, you certainly can have TIFF encapsulate a G3, and mgetty wouldn't have much trouble with that. However, that leaves you with the question - what does mgetty do if it's not a G3 that's been encapsulated? It would have to convert it. And then we would encounter situations where mgetty's conversion speeds couldn't meet the class II FAX transmission timeouts, and you've wasted telephone time... Ditto on reception. Indeed, there is a real possibility that mgetty would not be able to keep up if the input or output file was anything other than a G3. "Approaching this from another viewpoint, we should also remember that mgetty is a transfer protocol and implementation. *Not* conversion software. mgetty needs to read and write G3s, and that's all. Leave conversions to other software." And from Gert Doering: "Well, TIFF is a very complex file format, that can support dozens of different page data encodings, different byte / bit orderings, multiple pages per file, and so on. While TIFF is a flexible format, parsing it is a complex task. "In contrast, mgetty's "g3" files are raw G3 data. No headers, no formatting, no need for the transmission code to dig around in the file to find the actual page data. One page per file, simplest possible. "Ignoring TIFF (leaving TIFF conversions to outside software) simplifies mgetty and sendfax enormously, but doesn't complicate the user interface much, as long as "faxspool" or similar tools are used that will hide the internals, that is, how the fax backend expect its data, from the user. To be precise, leaving out TIFF support *simplifies* mgetty. Many Unix programs can read pbm and converting g3 -> pbm is very easy, while I haven't seen a good *multipage*-Tiff - to - PBM converter yet."
Subject: Why doesn't mgetty use the modem's autoanswer capabilities? 1. Because it isn't possible to distinguish a fax from a data call if you don't have full modem control. Besides, it will make sure that the modem doesn't answer the phone while the host isn't ready for it. 2. And callerid won't work without extreme difficulty.
Subject: Why mgetty ignores /dev/tty* dialin, /dev/cua* dialout conventions: [Under Linux and most other Unices (excepting SunOS) mgetty should be set on the tty* devices, and the cua* devices should be ignored entirely:] From: "Theodore Y. Ts'o" <tytso@mit.edu> /dev/ttySxx devices are fully POSIX-compliant TTY devices. If you are only going to be using one set of tty devices, you should be using /dev/ttySxx. /dev/cuaXX devices are different from /dev/ttySXX in two ways --- first of all, they will allow you to open the device even if CLOCAL is not set and the O_NONBLOCK flag was not given to the open device. This allows programs that don't use the POSIX-mondated interface for opening /dev/ttySxx devices to be able to use /dev/cuaXX to make outgoing phone calls on their modem (cu stands for "callout", and is taken from SunOS). The second way in which /dev/cuaXX differs from /dev/ttySXX is that if they are used, they will trigger a simplistic kernel-based locking scheme: If /dev/ttySXX is opened by one or more processes, then an attempt to open /dev/cuaXX will return EAGAIN. If /dev/cuaXX is opened by one or more processes, then an attempt to open /dev/ttySXX will result the open blocking until /dev/cuaXX is closed, and the carrier detect line goes high. While this will allow for simple lockouts between a user using a modem for callout and a getty listening on the line for logins, it doesn't work if you need to arbitrate between multiple programs wanting to do dialout --- for example, users wanting to do dialout and UUCP. I originally implemented the cuaXX/ttySXX lockout mechanism back before FSSTND established a standard convention for the use of tty lock files. Now that it's there, people should use the tty lock files and not try using /dev/cuaXX. The only reason why /dev/cuaXX hasn't disappeared yet is for backwards compatibility reasons. - Ted [Under SunOS *everything* should use cua*, as follows:] From: Gert Doering <gert@muc.de> The two-device scheme is meant to prevent multiple processes from accessing the same physical device at the same time. Since mgetty opens the port with O_NDELAY, the kernel sees a process on tty* (mgetty) and prevents any open() on cua* (uucico, cu, ...). So, you have to use the same device for both program types, and that's cua*.
Subject: Troubleshooting questions & answers From: gert@greenie.muc.de Q: I keep getting the error code +FHNG:50 or +FHNG:54 after sending a page. Sometimes it says "page bad, retrain requested" and infinitely resends the page. A: This error means that something went wrong between the two machines, while your end was sending the page data. In the case of +FHNG:50 or +FHNG:54, the other end most likely simply hung up (so your modem couldn't get any page transfer status at all), in the other case, the receiver complained that it didn't like the data on the page. The most common reason for this behaviour is that you used a copy of ``pbmtog3'' that came from the ``pbmplus'' distribution and doesn't have my patch included (Mind you, the pbmtog3 program is required for the page headers that faxspool puts on top of each page!). If that is not the reason, there may be flow control problems, or the line have simply has been very noisy, or so. Get in touch with the receiver, and find out whether the page looks good or whether there are lines missing, others corrupted, ... - if there are errors, check your flow control setting. If there are no errors whatsoever, and you're sure that you use my version of pbmtog3 (called pbm2g3 or a patched version of pbmplus', then I'm out of wits - something's broken in the modem. Maybe you should upgrade your ROM version. Q: When receiving faxes, I get the +FCON message logged, then mgetty says "starting fax receiver". fax_wait_for(OK) is called, logs some random junk bytes, and gives up after a minute, complaining about "timeout". A: Most likely, you have a modem that switches baud rate to 19200 bps right after sending the +FCON message to the host, and the normal port speed is something else. Check policy.h whether FAX_RECEIVE_SWITCHBD is defined, and change the setting (if the modem does *not* change speed, but the define is *set*, the effect will be similar). Better yet, with the runtime configurable stuff, is to add the entry switchbd <nnn>" in mgetty.config Q: I keep changing values in policy.h, but nothing changes. A: maybe you've had an older version of mgetty installed to /usr/local/bin/mgetty and are calling this from /etc/init? Newer versions are installed in /usr/local/sbin/mgetty. Check the time stamp on the mgetty you just compiled vs. the mgetty listed in /etc/inittab. Q: Half of the faxes that I receive are too short, they look as if every second pixel line is missing. A: Well, they *are* short: most likely, they are received in normal resolution (204x98 dpi) instead of fine resolution (204x196 dpi). You can see it in the filename, if it starts with "ff*", it's fine, if it starts with "fn*", it's normal resolution. To ``stretch'' a normal resolution fax to proper proportions, use ``g32pbm -stretch fn...'' Q: login complains with ``no utmp entry, must execute login from the lowest level sh'' A: I *told* you not to fiddle with the ``utmp'' field... - most likely, in your ``login.config'' file, the utmp field for the entry calling /bin/login isn't "-". Another reason could be a faulty /etc/init (hits only Linux users) or a corrupted /etc/utmp file. In that case, reboot your machine. Q: When mgetty is running and I dial out, I do not get "CONNECT" but only junk, as "+FCO", "+FTI:", "+FHS:20" A: Well, yes, that's a problem with the 2.0 implementation in mgetty. That is: while mgetty is running, the modem is in "AT+FCLASS=2.0" mode and expects to connect to a fax on the remote side. (With class 2, we worked around this by setting +FCLASS=0;+FAA=1, but that will make the modem answer in class 2, not 2.0 [subject to further testing!]) Solution: in the program dialing out, initialize the modem with "AT+FCLASS=0". Most likely, a modem reset (ATZ) will also help. Q: every time mgetty starts up, the permissions of my tty device get changed and I have to issue "chmod +w /dev/ttySx" to be able to dial out. A: that's not a bug, that's a feature. You don't *want* to allow anybody using your machine to be able to dial out (think of your phone costs!), so it's a security issue. If you *want* to allow dialout for everyone, #define FILE_MODE 0666 in policy.h. I would not recommend it, I would give access to a special group, and put every one that may dial out into this group. Q: I have a Linux system, and while trying to dial out on /dev/cua1 (mgetty is running on /dev/ttyS1), it says "device busy" (EBUSY)??? A: use the same device (always!!) for dial-in and dial-out. On Linux, use /dev/ttySx, on SunOS and *BSD use /dev/cuax. Q: If I create a fax file with "gs -sDEVICE=dfaxhigh ..." and send it with sendfax, everything works *great*. If I run it through "faxspool", the receiving side reports an error. Is the "g3cat" program broken? A: No, g3cat isn't the problem. The real problem is "pbmtog3", and I bet you have the pbmtog3 program from the pbmplus distribution installed. This program is *broken* (patch is in mgetty/patches/pbmtog3.p1), that is, it doesn't create proper T.4/G3 fax data. Thus, the receiving fax machine will get a fax that has some corrupt lines (the page header) and will complain about it. Patch pbmtog3, or use mgetty's pbm2g3. It's faster anyway. Q: mgetty doesn't accept FidoNet calls. I get log entries like this: 10/30 01:54:54 ##### data dev=ttyS1, pid=3401, caller=none, conn='38400/V32b 14400/V42b', name='', cmd='/bin/login', user='**EMSI_INQC816**EMSI_INQC816q.' or this: 10/30 05:31:03 ##### data dev=ttyS1, pid=7238, caller=none, conn='38400/ZyX 16800/V42b', name='', cmd='/bin/login', user='q.q.q.' A: did you compile mgetty with -DFIDO defined? I don't think so. If -DFIDO isn't set, mgetty doesn't know about fido. Q: Some of my programs use binary lockfiles and some use ASCII lockfiles. Why does mgetty complain? Can't it recognize both? A: Mgetty complains because your system configuration is _wrong_. These error messages are there to help the system administrator notice a *severe configuration error* on his site. If all programs would understand both types of Locking, the messages would be silly, but since kermit usually simply ignores ascii locks, and uucico does so for binary locks, the situation is *highly* error-prone, and sysadmins should *SEE* this. Recompile your applications that use the modem so that all agree on the lockfile types. Q: My modem and I share one phone line. Now I answered the phone and a modem greets me. How can I make mgetty take over? A: Send the signal SIGUSR1 to the mgetty process. It will then answer the phone. Q: I can fax only one page, then I get an error A: When you see something like this in your log: > 03/22 19:15:58 yS1 fax_wait_for: string 'OK'** found ** > 03/22 19:15:58 yS1 fax_send: 'AT+FET=0' > 03/22 19:15:58 yS1 fax_wait_for(OK) > 03/22 19:15:58 yS1 fax_read_byte: read returned 0: Unknown error > 03/22 19:15:58 yS1 fax_get_line: cannot read byte, return: Unknown error > 03/22 19:15:58 ##### failed transmitting f1.g3: +FHS:-4, time=55s you should define FAX_SEND_IGNORE_CARRIER in policy.h and recompile your binaries. There are some modems that drop the DCD line between pages. Alternatively, you can define ''ignore-carrier true'' in your config file. Q: The message "WARING: DSR off - modem turned off or bad cable?" keeps showing up in the mgetty logfile. A: If you see this message, it basically means that mgetty can't get the status of dsr (data set ready). This can be because the cable is bad or because you are using mgetty on solaris. Solaris doesn't give you the status of dsr. If you are running mgetty on a different platform, you might consider checking your cable or the modem setting.
Subject: Programs generating "invalid" Postscript that can't converted to the G3 format for sendfax From: Gert Doering <gert@greenie.muc.de> Right now the list of programs generating "invalid" postscript (causing Ghostscript to create G3 files with wrong line width, in turn causing sendfax to fail) includes: FrameMaker 4.0 WinWord (dunno which version) dvipsk 5.58f Gert Doering wrote on Sun, 22 Dec 1996 00:26:55 +0100 in message <m0vbaoh-0004B5C@greenie.muc.de>: Interesting enough, I tried dvipsk 5.58f today, and it does *NOT* emit any of those bad "setpagedevice" commands, and thus the resulting postscript *will* generate correct page sizes. So maybe it's sufficient to upgrade your dvips program to the most recent version. Maybe it's necessary to tell *ghostscript* what the "right" paper size is supposed to be (A4 -- but you must make sure that dvips makes "a4" as well!), by specifying "gs -sPAPERSIZE=a4". For some people, even that does not suffice (some strange interaction between different paper sizes in different programs), so it may help to post-process the G3 files with "g3cat" (from mgetty 0.99*, versions after July 96!), or with "g32pbm badfile.g3 | pbm2g3 >goodfile.g3". The latter will definitely help.
Subject: My ZyXEL doesn't work right after a ROM upgrade: What's wrong? From: felix@escape.vsse.in-berlin.de Do a full modem reset after upgrading the firmware. This is not described in the German ZyXEL manual (is it described in the English one?) but should be done in any case.
Subject: Why the occasional "tcsetattr failed: I/O error" message? From: gert@greenie.muc.de Q: Occasionally, mainly after "clean" user logouts (that is, the user typed "exit" instead of just hanging up), I get the message 09/08 21:26:26 yS2 lowering DTR to reset Modem 09/08 21:26:27 yS2 tcsetattr failed: I/O error in the mgetty log file, and a similar I/O error message in the syslog file. A: Well, this is a Linux and SunOS specific problem: if the modem is still connected to the other end when mgetty starts, mgetty will force it to hangup by lowering DTR (and sending +++ATH, in case DTR drop won't suffice). This will make the modem lower the DCD (carrier detect) line. Unfortunately, this will trigger a security mechanism in the Linux kernel, which will prevent all further access via that file descriptor. This is done to prevent one well-known password hack (I won't that explain in detail). Mgetty knows about that problem, and, upon noticing an error at this point during modem initialization, will simply reopen the port and redo all modem / port setup stuff. Because suppressing that error message would be messy, it keeps appearing, but it is harmless (... "trying again").
Subject: When is mgetty actually running? (i.e. what can mgetty control?) From: Klaus Lichtenwalder <Lichtenwalder@ACM.org> At what moments can mgetty exert control over the line? Let's consider mgetty's life span: at some time (e.g. system boot, init assumes the specified run level and starts mgetty) mgetty starts and (simplified) checks for the lock file on the device it has to control. If there's no lock file, it initializes the modem and wait's for an event on the line. If a character arrives, mgetty does not read it but first checks the lock file. * If a lock file is present, mgetty knows some{body,thing} wants to dial out and periodically checks for the existence of the lock file. After the lock file is gone, the device is free and mgetty simply exits. It'll get restarted by init, so the modem line will get reinitialized. * If no lock file is present, the modem most probably sent a RING, so we go check for the expected word (= RING) and send our answer_chat. If it's a fax call (and the modem can receive faxes and we allow receiving them) we get the pages, store 'em away and exit, thus restarting mgetty, see above. If it's a data call (I ignore DISTINGIVE_RING and Caller_ID features for now), we prompt for the login and wait for an answer. After the answer is read, it's checked against the login.config file and the appropriate program get's exec'd by mgetty, which means, there's *no* mgetty for that line. Only after the termination of the connection, when the other process(es) exit(s), mgetty will be restarted by init.
Subject: The user's shell doesn't get killed after the line drops From: Gert Doering <gert@greenie.muc.de> > why doesn't mgetty kill the user's shell when the user just hangs up > the modem, without doing 'logout'? [Mod: or the line simply crashes] How should mgetty kill a user's shell? While the user is logged in, mgetty is *not running*. The kernel will signal the shell via the SIGHUP signal when the DCD line on the modem drops. Then the shell will exit, and init will re-start mgetty. Unfortunately, the BASH shell is very broken in various versions and will ignore the SIGHUP signal, so that could be one reason why it isn't exiting. Another reason could be an improper modem setup (AT&C0), make sure that the modem raises and lowers the DCD line properly (check with the modem manual) and that your serial cable is OK (swap it with another one for testing).
Subject: AutoPPP appears in the "who" listing From: Gert Doering <gert@greenie.muc.de> If you use the /AutoPPP/ option for automatically creating a ppp connection, the user name does not appear in the who list. Instead, something like AutoPPP or ppp is displayed. Solution: you have to patch pppd, that's not mgetty's issue and thus can't resolved patching mgetty. If you have the patched pppd, this is how it works. You have to add the option "login" to pppd in login.config and change the third column to "-" (in the example it's a_ppp or ppp).
Subject: Things to think of if using AutoPPP, or, as you might call it, ppp connections From: Gert Doering <gert@greenie.muc.de> You can't get a ppp connection going. So, what should you check before calling for help in the list. Run mgetty with a debug level high enough to see what login it will try. It might not be wrong to just use level 9 to see everything happening. Scenario 1: mgetty recognizes AutoPPP: 03/11 12:06:31 yS1 match: user='/AutoPPP/', key='/AutoPPP/'*** hit! 03/11 12:06:31 yS1 login: utmp entry: ppp 03/11 12:06:31 yS1 looking for utmp entry... (my PID: 5313) 03/11 12:06:31 yS1 utmp + wtmp entry made 03/11 12:06:31 yS1 calling login: cmd='/usr/sbin/pppd', argv[]='pppd... 03/11 12:06:31 ##### data dev=ttyS1, pid=5313, caller=none, conn='LAPM', name='' At this point, mgetty executes pppd and has nothing to do with connection failures, failing authorization, the police banging at your door or anything else. Check pppd's logs for any trouble. If you use "who" and the only thing you can see is "a_ppp", go check your pppd sources. It's pppd's job to forge a utmp entry It looks like some unix clients should explicitely send the string "/AutoPPP/" as there seems to be a problem in connecting. Mgetty doesn't seem to get ppp-frames and waits for something it can decide what to do. As you are most probably using a script for the connection, there should be no problem to send that string.
Subject: Part 3: Compatibility Issues
Subject: Suspicious fax machines From: hm@ix.de (Harald Milz) I'm collecting all data concerning suspective fax machines, i.e. those which made problems in cooperating with sendfax. The main reason is to find out whether there are specific fax machines that refuse to work with sendfax and/or your fax modem. As a goal, we will be able to track down the bug(s). To contribute, please fill in the following template and send it to me (hm@ix.de): 1. <fax machine's brand and model> 2. <corresponding fax number> (optional) 3. <fax modem brand and model> 4. <fax modem's firmware revision> # tbd from ATI1 5. <protocol parameters> # tbd from Faxlog 6. <errlog line from Faxlog> # tbd from Faxlog 7. <remarks> If you encounter problems with a fax machine, please call the receiving party and ask them for their fax machine's brand & model and if they are willing to offer their machine for some (limited) testing. The more exact your data is (the first 3 entries aren't too good :-} ), the better the result will be, hopefully. This list is posted once a month (automatically) and if five new entries were added to it (manually). Here's what's already in the list: 1. Panasonic Panafax UF311 2. +49 89 74824899 3. ZyXEL U1496EG+ 4. U1496EG V 6.10g P 5. +FDCS:1,3,0,2,0,0,0,4 6. +FHNG:50 (Unspecified Transmit Phase D error) 7. when sending 15 pg, connection broke after 6 pg. 1. NEC Nefax 17 2. +49 2242 82114 3. ZyXEL U1496EG+ 4. U1496EG V 6.10g P 5. +FDCS:1,3,0,2,1,0,0,4 6. +FHNG:50 (Unspecified Transmit Phase D error) 7. machine didn't refuse when sending only 3 pages earlier. This time, 15 pg were sent. 1. Telekom AF-310 2. +49 7231 560851 3. ZyXEL U1496 E / 6.10a, E+ / 6.01, E+ / 6.11a 4. 5. +FDCS:1,3,0,2,0,0,0,4 6. +FTPS:2 -> page bad, retrain requested 7. sendfax hangs up after three tries. received fax shows black and white boxes at the footer, such as, ### ### ### ### ### ### ### ### ### ### ... ### ### ### ### ###
Subject: Part 4: Compiling, installing and using vgetty
Subject: Compiling vgetty From: Marc Eberhard <marc@poseidon.thphy.uni-duesseldorf.de>, Klaus Lichtenwalder <Lichtenwalder@ACM.org> After having set up mgetty for compile (i.e. copying policy.h-dist to policy.h and editing it), you change to the voice/ directory and type make. For installation (make install) be sure to copy voice.conf-dist to the mgetty configuration directory (usually /usr/local/etc/mgetty+sendfax) as voice.conf and edit it, using the comments in that file.
Subject: US Robotics voice format converter From: Scott Hutton <shutton@indiana.edu> There's a script I wrote in voice/pvftools called "extract_gsm" that extracts the GSM data from a US Robotics "rmd" file. Once you have that, and you have a version of "sox" that can convert .gsm files in to .au (or other format) files, you're in business. I found the necessary patches for sox after a bit of digging: http://kbs.cs.tu-berlin.de/~jutta/toast.html You'll need the GSM library before you try to apply the sox patches. It's too bad sox doesn't come with GSM support--it seems to have about everything else... Also, Thomas Hellstroem (thomas@vtd.volvo.se) had some C programs to extract GSM data and to "pack" GSM data into rmd files off of his page. Unforutnately, I didn't save the URL. -Scott Hutton, UCS Messaging Team, Indiana Univeristy

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