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diff --git a/share/doc/handbook/dialup.sgml b/share/doc/handbook/dialup.sgml deleted file mode 100644 index c0e032b..0000000 --- a/share/doc/handbook/dialup.sgml +++ /dev/null @@ -1,810 +0,0 @@ -<!-- This is an SGML document in the linuxdoc DTD of the Tutorial for - Configuring a FreeBSD for Dialup Services by Guy Helmer. - $Id$ - -<!DOCTYPE linuxdoc PUBLIC "-//Linux//DTD linuxdoc//EN"> - - -<article> - -<title> -Configuring FreeBSD for Dialup Services -<author>Guy Helmer, <tt/ghelmer@alpha.dsu.edu/ -<date>v0.1, 28 March 1995 -<abstract> - ---> - -<sect><heading>Dialin service<label id="dialup"></heading> - -<p><em>Contributed by &a.ghelmer;.</em> - -This document provides suggestions for configuring a FreeBSD system to -handle dialup modems. This document is written based on the author's -experience with FreeBSD versions 1.0, 1.1, and 1.1.5.1 (and experience -with dialup modems on other UNIX-like operating systems); however, -this document may not answer all of your questions or provide examples -specific enough to your environment. The author cannot be responsible -if you damage your system or lose data due to attempting to follow the -suggestions here. - -<sect1><heading>Prerequisites<label id="dialup:prereqs"></> -<p> - -To begin with, the author assumes you have some basic knowledge of -FreeBSD. You need to have FreeBSD installed, know how to edit files -in a UNIX-like environment, and how to look up manual pages on the -system. As discussed below, you will need certain versions of FreeBSD, -and knowledge of some terminology & modem and cabling. - -<sect2><heading>FreeBSD Version</heading> -<p> - -First, it is assumed that you are using FreeBSD version 1.1 or higher -(including versions 2.x). FreeBSD version 1.0 included two different -serial drivers, which complicates the situation. Also, the serial -device driver (<tt/sio/) has improved in every release of FreeBSD, so -more recent versions of FreeBSD are assumed to have better and more -efficient drivers than earlier versions. - -<sect2><heading>Terminology</heading> -<p> - -A quick rundown of terminology: - -<descrip> - -<tag/bps/ Bits per Second - the rate at which data is transmitted - -<tag/DTE/ Data Terminal Equipment - for example, your computer - -<tag/DCE/ Data Communications Equipment - your modem - -<tag/RS-232/ EIA standard for serial communications via hardware - -</descrip> - -If you need more information about these terms and data communications -in general, the author remembers reading that <em/The RS-232 Bible/ -(anybody have an ISBN?) is a good reference. - -When talking about communications data rates, the author does not use -the term <bf/baud/. Baud refers to the number of electrical state -transitions that may be made in a period of time, while <bf/bps/ (bits -per second) is the ``correct'' term to use (at least it does not seem -to bother the curmudgeons quite a much). - -<sect2><heading>External vs. Internal Modems</heading> -<p> - -External modems seem to be more convenient for dialup, because -external modems often can be semi-permanently configured via -parameters stored in non-volatile RAM and they usually provide lighted -indicators that display the state of important RS-232 signals. -Blinking lights impress visitors, but lights are also very useful to -see whether a modem is operating properly. - -Internal modems usually lack non-volatile RAM, so their configuration -may be limited only to setting DIP switches. If your internal modem -has any signal indicator lights, it is probably difficult to view the -lights when the system's cover is in place. - -<sect2><heading>Modems and Cables</heading> -<p> - -A background knowledge of these items is assumed - -<itemize> - -<item> You know how to connect your modem to your computer so that the -two can communicate (unless you have an internal modem, which does not -need such a cable) - -<item> You are familiar with your modem's command set, or know where -to look up needed commands - -<item> You know how to configure your modem (probably via a terminal -communications program) so you can set the non-volatile RAM -parameters - -</itemize> - -The first, connecting your modem, is usually simple - most -straight-through serial cables work without any problems. You need to -have a cable with appropriate connectors (DB-25 or DB-9, male or -female) on each end, and the cable must be a DCE-to-DTE cable with -these signals wired: - -<itemize> -<item> Transmitted Data (<tt/SD/) -<item> Received Data (<tt/RD/) -<item> Request to Send (<tt/RTS/) -<item> Clear to Send (<tt/CTS/) -<item> Data Set Ready (<tt/DSR/) -<item> Data Terminal Ready (<tt/DTR/) -<item> Carrier Detect (<tt/CD/) -<item> Signal Ground (<tt/SG/) -</itemize> - -FreeBSD needs the <tt/RTS/ and <tt/CTS/ signals for flow-control at -speeds above 2400bps, the <tt/CD/ signal to detect when a call has -been answered or the line has been hung up, and the <tt/DTR/ signal to -reset the modem after a session is complete. Some cables are wired -without all of the needed signals, so if you have problems, such as -a login session not going away when the line hangs up, you may have a -problem with your cable. - -The second prerequisite depends on the modem(s) you use. If you do not -know your modem's command set by heart, you will need to have the -modem's reference book or user's guide handy. Sample commands for USR -Sportster 14,400 external modems will be given, which you may be able -to use as a reference for your own modem's commands. - -Lastly, you will need to know how to setup your modem so that it will -work well with FreeBSD. Like other UNIX-like operating systems, -FreeBSD uses the hardware signals to find out when a call has been -answered or a line has been hung up and to hangup and reset the modem -after a call. FreeBSD avoids sending commands to the modem or -watching for status reports from the modem. If you are familiar with -connecting modems to PC-based bulletin board systems, this may seem -awkward. - -<sect2><heading>Serial Interface Considerations</heading> -<p> - -FreeBSD supports NS8250-, NS16450-, NS16550-, and NS16550A-based EIA -RS-232C (CCITT V.24) communications interfaces. The 8250 and 16450 -devices have single-character buffers. The 16550 device provides a -16-character buffer, which allows for better system performance. -(Bugs in plain 16550's prevent the use of the 16-character buffer, so -use 16550A's if possible). Because single-character-buffer devices -require more work by the operating system than the 16-character-buffer -devices, 16550A-based serial interface cards are much prefered. If -the system has many active serial ports or will have a heavy load, -16550A-based cards are better for low-error-rate communications. - -<sect1><heading>Quick Overview</heading> -<p> - -Here is the process that FreeBSD follows to accept dialup logins. A -<tt/getty/ process, spawned by <tt/init/, patiently waits to open the -assigned serial port (<tt>/dev/ttyd0</tt>, for our example). The -command <tt/ps ax/ might show this: - -<tscreen><verb> - 4850 ?? I 0:00.09 /usr/libexec/getty V19200 ttyd0 -</verb></tscreen> - -When a user dials the modem's line and the modems connect, the <tt/CD/ -line is asserted by the modem. The kernel notices that carrier has -been detected and completes <tt/getty/'s open of the port. <tt/getty/ -sends a <tt/login:/ prompt at the specified initial line speed. -<tt/getty/ watches to see if legitimate characters are received, and, -in a typical configuration, if it finds junk (probably due to the -modem's connection speed being different than <tt/getty/'s speed), -<tt/getty/ tries adjusting the line speeds until it receives -reasonable characters. - -We hope <tt/getty/ finds the correct speed and the user sees a -<tt/login:/ prompt. After the user enters his/her login name, -<tt/getty/ executes <tt>/usr/bin/login</tt>, which completes the login -by asking for the user's password and then starting the user's shell. - -Let's dive into the configuration... - -<sect1><heading>Kernel Configuration</heading> -<p> - -FreeBSD kernels typically come prepared to search for four serial -ports, known in the PC-DOS world as <tt/COM1:/, <tt/COM2:/, -<tt/COM3:/, and <tt/COM4:/. FreeBSD can presently also handle -``dumb'' multiport serial interface cards, such as the Boca Board -1008 and 2016 (please see the manual page <tt/sio(4)/ for kernel -configuration information if you have a multiport serial card). The -default kernel only looks for the standard COM ports, though. - -To see if your kernel recognizes any of your serial ports, watch for -messages while the kernel is booting, or use the -<tt>/sbin/dmesg</tt> command to replay the kernel's boot messages. In -particular, look for messages that start with the characters <tt/sio/. -Hint: to view just the messages that have the word <tt/sio/, use the -command: - -<tscreen><verb> -/sbin/dmesg | grep 'sio' -</verb></tscreen> - -For example, on a system with four serial ports, these are the -serial-port specific kernel boot messages: - -<tscreen><verb> -sio0 at 0x3f8-0x3ff irq 4 on isa -sio0: type 16550A -sio1 at 0x2f8-0x2ff irq 3 on isa -sio1: type 16550A -sio2 at 0x3e8-0x3ef irq 5 on isa -sio2: type 16550A -sio3 at 0x2e8-0x2ef irq 9 on isa -sio3: type 16550A -</verb></tscreen> - -If your kernel does not recognize all of your serial ports, you will -probably need to configure a custom FreeBSD kernel for your system. - -Please see the BSD System Manager's Manual chapter on ``Building -Berkeley Kernels with Config'' [the source for which is in -<tt>/usr/src/share/doc/smm</tt>] and ``FreeBSD Configuration -Options'' [in <tt>/sys/conf/options</tt> and in -<tt>/sys/<em>arch</em>/conf/options.<em>arch</em></tt>, with -<em>arch</em> for example being <tt>i386</tt>] for more -information on configuring and building kernels. You may have to -unpack the kernel source distribution if have not installed the system -sources already (<tt>srcdist/srcsys.??</tt> in FreeBSD 1.1, -<tt>srcdist/sys.??</tt> in FreeBSD 1.1.5.1, or the entire source -distribution in FreeBSD 2.0) to be able to configure and build -kernels. - -Create a kernel configuration file for your system (if you have not -already) by <tt/cd/ing to <tt>/sys/i386/conf</tt>. Then, if you are -creating a new custom configuration file, copy the file GENERICAH (or -GENERICBT, if you have a BusTek SCSI controller on FreeBSD 1.x) to -<em/YOURSYS/, where <em/YOURSYS/ is the name of your system, but in -upper-case letters. Edit the file, and change the device lines: - -<tscreen><verb> -device sio0 at isa? port "IO_COM1" tty irq 4 vector siointr -device sio1 at isa? port "IO_COM2" tty irq 3 vector siointr -device sio2 at isa? port "IO_COM3" tty irq 5 vector siointr -device sio3 at isa? port "IO_COM4" tty irq 9 vector siointr -</verb></tscreen> - -You can comment-out or completely remove lines for devices you do not -have. If you have a multiport serial board, such as the Boca Board -BB2016, please see the <tt/sio(4)/ man page for complete information -on how to write configuration lines for multiport boards. Be careful -if you are using a configuration file that was previously used for a -different version of FreeBSD because the device flags have changed -between versions. - -Note that <tt/port "IO_COM1"/ is a substitution for <tt/port 0x3f8/, -<tt/IO_COM2/ is <tt/0x2f8/, <tt/IO_COM3/ is <tt/0x3e8/, and -<tt/IO_COM4/ is <tt/0x2e8/, which are fairly common port addresses for -their respective serial ports; interrupts 4, 3, 5, and 9 are fairly -common interrupt request lines. Also note that regular serial ports -<bf>cannot</bf> share interrupts on ISA-bus PCs (multiport boards have -on-board electronics that allow all the 16550A's on the board to share -one or two interrupt request lines). - -When you are finished adjusting the kernel configuration file, use the -program <tt/config/ as documented in ``Building Berkeley Kernels with -Config'' and the <tt/config(8)/ manual page to prepare a kernel -building directory, then build, install, and test the new kernel. - -<sect1><heading>Device Special Files</heading> -<p> - -Most devices in the kernel are accessed through ``device special -files'', which are located in the <tt>/dev</tt> directory. The -<tt/sio/ devices are accessed through the <tt>/dev/ttyd?</tt> -(dial-in) and <tt>/dev/cua0?</tt> (call-out) devices. On FreeBSD -version 1.1.5 and higher, there are also initialization devices -(<tt>/dev/ttyid?</tt> and <tt>/dev/cuai0?</tt>) and locking devices -(<tt>/dev/ttyld?</tt> and <tt>/dev/cual0?</tt>). The initialization -devices are used to initialize communications port parameters each -time a port is opened, such as <tt>crtscts</tt> for modems which use -<tt>CTS/RTS</tt> signaling for flow control. The locking devices are -used to lock flags on ports to prevent users or programs changing -certain parameters; see the manual pages <tt/termios(4)/, <tt/sio(4)/, -and <tt/stty(1)/ for information on the terminal settings, locking -& initializing devices, and setting terminal options, -respectively. - -<sect2><heading>Making Device Special Files</heading> -<p> - -A shell script called <tt/MAKEDEV/ in the <tt>/dev</tt> directory -manages the device special files. (The manual page for -<tt/MAKEDEV(8)/ on FreeBSD 1.1.5 is fairly bogus in its discussion of -<tt/COM/ ports, so ignore it.) To use <tt/MAKEDEV/ to make dialup -device special files for <tt/COM1:/ (port 0), <tt/cd/ to <tt>/dev</tt> -and issue the command <tt/MAKEDEV ttyd0/. Likewise, to make dialup -device special files for <tt/COM2:/ (port 1), use <tt/MAKEDEV ttyd1/. - -<tt/MAKEDEV/ not only creates the <tt>/dev/ttyd?</tt> device special -files, but also creates the <tt>/dev/cua0?</tt> (and all of the -initializing and locking special files under FreeBSD 1.1.5 and up) and -removes the hardwired terminal special file <tt>/dev/tty0?</tt>, if it -exists. - -After making new device special files, be sure to check the -permissions on the files (especially the <tt>/dev/cua*</tt> files) to -make sure that only users who should have access to those device -special files can read & write on them - you probably do not want -to allow your average user to use your modems to dialout. The default -permissions on the <tt>/dev/cua*</tt> files should be sufficient: - -<tscreen><verb> -crw-rw---- 1 uucp dialer 28, 129 Feb 15 14:38 /dev/cua01 -crw-rw---- 1 uucp dialer 28, 161 Feb 15 14:38 /dev/cuai01 -crw-rw---- 1 uucp dialer 28, 193 Feb 15 14:38 /dev/cual01 -</verb></tscreen> - -These permissions allow the user <tt/uucp/ and users in the group -<tt/dialer/ to use the call-out devices. - -<sect1><heading>Configuration Files</heading> -<p> - -There are three system configuration files in the <tt>/etc</tt> -directory that you will probably need to edit to allow dialup access to -your FreeBSD system. The first, <tt>/etc/gettytab</tt>, contains -configuration information for the <tt>/usr/libexec/getty</tt> daemon. -Second, <tt>/etc/ttys</tt> holds information that tells -<tt>/sbin/init</tt> what <tt/tty/ devices should have <tt/getty/ -processes running on them. Lastly, you can place port initialization -commands in the <tt>/etc/rc.serial</tt> script if you have FreeBSD -1.1.5.1 or higher; otherwise, you can initialize ports in the -<tt>/etc/rc.local</tt> script. - -There are two schools of thought regarding dialup modems on UNIX. One -group likes to configure their modems and system so that no matter at -what speed a remote user dials in, the local computer-to-modem RS-232 -interface runs at a locked speed. The benefit of this configuration -is that the remote user always sees a system login prompt immediately. -The downside is that the system does not know what a user's true data -rate is, so full-screen programs like Emacs will not adjust their -screen-painting methods to make their response better for slower -connections. - -The other school configures their modems' RS-232 interface to vary its -speed based on the remote user's connection speed. For example, -V.32bis (14.4 Kbps) connections to the modem might make the modem run -its RS-232 interface at 19.2 Kbps, while 2400 bps connections make the -modem's RS-232 interface run at 2400 bps. Because <tt/getty/ does not -understand any particular modem's connection speed reporting, -<tt/getty/ gives a <tt/login:/ message at an initial speed and watches -the characters that come back in response. If the user sees junk, -it is assumed that they know they should press the -<tt><Enter></tt> key until they see a recognizable prompt. If -the data rates do not match, <tt/getty/ sees anything the user types as -``junk'', tries going to the next speed and gives the <tt/login:/ -prompt again. This procedure can continue ad nauseum, but normally -only takes a keystroke or two before the user sees a good prompt. -Obviously, this login sequence does not look as clean as the former -``locked-speed'' method, but a user on a low-speed connection should -receive better interactive response from full-screen programs. - -The author will try to give balanced configuration information, but is -biased towards having the modem's data rate follow the connection -rate. - -<sect2><heading>/etc/gettytab</heading> -<p> - -<tt>/etc/gettytab</tt> is a <tt/termcap(5)/-style file of -configuration information for <tt/getty(8)/. Please see the -<tt/gettytab(4)/ manual page for complete information on the format of -the file and the list of capabilities. - -<sect3><heading>Locked-Speed Config</heading> -<p> - -If you are locking your modem's data communications rate at a -particular speed, you probably will not need to make any changes to -<tt>/etc/gettytab</tt>. - -<sect3><heading>Matching-Speed Config</heading> -<p> - -You will need to setup an entry in <tt>/etc/gettytab</tt> to give -<tt/getty/ information about the speeds you wish to use for your -modem. If you have a 2400 bps modem, you can probably use the -existing <tt/D2400/ entry. This entry already exists in the FreeBSD -1.1.5.1 <tt/gettytab/ file, so you do not need to add it unless it is -missing under your version of FreeBSD: - -<tscreen><verb> -# -# Fast dialup terminals, 2400/1200/300 rotary (can start either way) -# -D2400|d2400|Fast-Dial-2400:\ - :nx=D1200:tc=2400-baud: -3|D1200|Fast-Dial-1200:\ - :nx=D300:tc=1200-baud: -5|D300|Fast-Dial-300:\ - :nx=D2400:tc=300-baud: -</verb></tscreen> - -If you have a higher speed modem, you will probably need to add an entry -in <tt>/etc/gettytab</tt>; here is an entry you could use for a 14.4 -Kbps modem with a top interface speed of 19.2 Kbps: - -<tscreen><verb> -# -# Additions for a V.32bis Modem -# -um|V300|High Speed Modem at 300,8-bit:\ - :nx=V19200:tc=std.300: -un|V1200|High Speed Modem at 1200,8-bit:\ - :nx=V300:tc=std.1200: -uo|V2400|High Speed Modem at 2400,8-bit:\ - :nx=V1200:tc=std.2400: -up|V9600|High Speed Modem at 9600,8-bit:\ - :nx=V2400:tc=std.9600: -uq|V19200|High Speed Modem at 19200,8-bit:\ - :nx=V9600:tc=std.19200: -</verb></tscreen> - -On FreeBSD 1.1.5 and later, this will result in 8-bit, no parity -connections. Under FreeBSD 1.1, add <tt/:np:/ parameters to the -<tt>std.<em/xxx/</tt> entries at the top of the file for 8 bits, no -parity; otherwise, the default is 7 bits, even parity. - -The example above starts the communications rate at 19.2 Kbps (for a -V.32bis connection), then cycles through 9600 bps (for V.32), 2400 -bps, 1200 bps, 300 bps, and back to 19.2 Kbps. Communications rate -cycling is implemented with the <tt/nx=/ (<bf/next table/) capability. -Each of the lines uses a <tt/tc=/ (<bf/table continuation/) entry to -pick up the rest of the ``standard'' settings for a particular data -rate. - -If you have a 28.8 Kbps modem and/or you want to take advantage of -compression on a 14.4 Kbps modem, you need to use a higher -communications rate than 19.2 Kbps. Here is an example of a -<tt/gettytab/ entry starting a 57.6 Kbps: - -<tscreen><verb> -# -# Additions for a V.32bis or V.34 Modem -# Starting at 57.6 Kbps -# -vm|VH300|Very High Speed Modem at 300,8-bit:\ - :nx=VH57600:tc=std.300: -vn|VH1200|Very High Speed Modem at 1200,8-bit:\ - :nx=VH300:tc=std.1200: -vo|VH2400|Very High Speed Modem at 2400,8-bit:\ - :nx=VH1200:tc=std.2400: -vp|VH9600|Very High Speed Modem at 9600,8-bit:\ - :nx=VH2400:tc=std.9600: -vq|VH57600|Very High Speed Modem at 57600,8-bit:\ - :nx=VH9600:tc=std.57600: -</verb></tscreen> - -If you have a slow CPU or a heavily loaded system and you do not have -16550A-based serial ports, you may receive sio ``silo'' errors at 57.6 -Kbps. - -<sect2><heading>/etc/ttys<label id="dialup:ttys"></heading> -<p> - -<tt>/etc/ttys</tt> is the list of <tt/ttys/ for <tt/init/ to monitor. -<tt>/etc/ttys</tt> also provides security information to <tt/login/ -(user <tt/root/ may only login on ttys marked <tt/secure/). See the -manual page for <tt/ttys(5)/ for more information. - -You will need to either modify existing lines in <tt>/etc/ttys</tt> or -add new lines to make <tt/init/ run <tt/getty/ processes automatically -on your new dialup ports. The general format of the line will be the -same, whether you are using a locked-speed or matching-speed -configuration: - -<tscreen><verb> -ttyd0 "/usr/libexec/getty xxx" dialup on -</verb></tscreen> - -The first item in the above line is the device special file for this -entry - <tt/ttyd0/ means <tt>/dev/ttyd0</tt> is the file that this -<tt/getty/ will be watching. The second item, <tt>"/usr/libexec/getty -<em/xxx/"</tt> (<em/xxx/ will be replaced by the initial <tt/gettytab/ -capability) is the process <tt/init/ will run on the device. The -third item, <tt/dialup/, is the default terminal type. The fourth -parameter, <tt/on/, indicates to <tt/init/ that the line is -operational. There can be a fifth parameter, <tt>secure</tt>, but it -should only be used for terminals which are physically secure (such as -the system console). - -The default terminal type (<tt/dialup/ in the example above) may -depend on local preferences. <tt/dialup/ is the traditional default -terminal type on dialup lines so that users may customize their login -scripts to notice when the terminal is <tt/dialup/ and automatically -adjust their terminal type. However, the author finds it easier at -his site to specify <tt/vt102/ as the default terminal type, since the -users just use VT102 emulation on their remote systems. - -After you have made changes to <tt>/etc/ttys</tt>, you may send the -<tt/init/ process a <tt/HUP/ signal to re-read the file. You can use -the command - -<tscreen><verb> -kill -1 1 -</verb></tscreen> - -to send the signal. If this is your first time setting up the system, -though, you may want to wait until your modem(s) are properly -configured and connected before signaling <tt/init/. - -<sect3><heading>Locked-Speed Config</heading> -<p> - -For a locked-speed configuration, your <tt/ttys/ entry needs to -have a fixed-speed entry provided to <tt/getty/. For a modem whose -port speed is locked at 19.2 Kbps, the <tt/ttys/ entry might look like -this: - -<tscreen><verb> -ttyd0 "/usr/libexec/getty std.19200" dialup on -</verb></tscreen> - -If your modem is locked at a different data rate, substitute the -appropriate name for the <tt>std.<em/speed/</tt> entry for -<tt/std.19200/ from <tt>/etc/gettytab</tt> for your modem's data rate. - -<sect3><heading>Matching-Speed Config</heading> -<p> - -In a matching-speed configuration, your <tt/ttys/ entry needs to -reference the appropriate beginning ``auto-baud'' (sic) entry in -<tt>/etc/gettytab</tt>. For example, if you added the above suggested -entry for a matching-speed modem that starts at 19.2 Kbps (the -<tt/gettytab/ entry containing the <tt/V19200/ starting point), your -<tt/ttys/ entry might look like this: - -<tscreen><verb> -ttyd0 "/usr/libexec/getty V19200" dialup on -</verb></tscreen> - -<sect2><heading>/etc/rc.serial or /etc/rc.local</heading> -<p> - -High-speed modems, like V.32, V.32bis, and V.34 modems, need to use -hardware (<tt>RTS/CTS</tt>) flow control. You can add <tt/stty/ -commands to <tt>/etc/rc.serial</tt> on FreeBSD 1.1.5.1 and up, or -<tt>/etc/rc.local</tt> on FreeBSD 1.1, to set the hardware flow -control flag in the FreeBSD kernel for the modem ports. - -For example, on a sample FreeBSD 1.1.5.1 system, -<tt>/etc/rc.serial</tt> reads: - -<tscreen><verb> -#!/bin/sh -# -# Serial port initial configuration - -stty -f /dev/ttyid1 crtscts -stty -f /dev/cuai01 crtscts -</verb></tscreen> - -which sets the <tt/termios/ flag <tt/crtscts/ on serial port #1's -(<tt/COM2:/) dialin and dialout initialization devices. - -On an old FreeBSD 1.1 system, these entries were added to -/etc/rc.local to set the <tt/crtscts/ flag on the devices: - -<tscreen><verb> -# Set serial ports to use RTS/CTS flow control -stty -f /dev/ttyd0 crtscts -stty -f /dev/ttyd1 crtscts -stty -f /dev/ttyd2 crtscts -stty -f /dev/ttyd3 crtscts -</verb></tscreen> - -Since there is no initialization device special file on FreeBSD -1.1, one has to just set the flags on the sole device special file and -hope the flags are not cleared by a miscreant. - -<sect1><heading>Modem Settings</heading> -<p> - -If you have a modem whose parameters may be permanently set in -non-volatile RAM, you will need to use a terminal program (such as Telix -under PC-DOS or <tt/tip/ under FreeBSD) to set the parameters. -Connect to the modem using the same communications speed as the -initial speed <tt/getty/ will use and configure the modem's -non-volatile RAM to match these requirements: - -<itemize> - -<item> <tt/CD/ asserted when connected - -<item> <tt/DTR/ asserted for operation; dropping DTR hangs up line -& resets modem - -<item> <tt/CTS/ transmitted data flow control - -<item> Disable <tt>XON/XOFF</tt> flow control - -<item> <tt/RTS/ received data flow control - -<item> Quiet mode (no result codes) - -<item> No command echo - -</itemize> - -Please read the documentation for your modem to find out what commands -and/or DIP switch settings you need to give it. - -For example, to set the above parameters on a USRobotics Sportster -14,400 external modem, one could give these commands to the modem: - -<tscreen><verb> -ATZ -AT&C1&D2&H1&I0&R2&W -</verb></tscreen> - -You might also want to take this opportunity to adjust other settings -in the modem, such as whether it will use V.42bis and/or MNP5 -compression. - -The USR Sportster 14,400 external modem also has some DIP switches -that need to be set; for other modems, perhaps you can use these -settings as an example: - -<itemize> - -<item> Switch 1: UP - DTR Normal - -<item> Switch 2: Do not care (Verbal Result Codes/Numeric Result Codes) - -<item> Switch 3: UP - Suppress Result Codes - -<item> Switch 4: DOWN - No echo, offline commands - -<item> Switch 5: UP - Auto Answer - -<item> Switch 6: UP - Carrier Detect Normal - -<item> Switch 7: UP - Load NVRAM Defaults - -<item> Switch 8: Do not care (Smart Mode/Dumb Mode) - -</itemize> - -Result codes should be disabled/suppressed for dialup modems to avoid -problems that can occur if <tt/getty/ mistakenly gives a <tt/login:/ -prompt to a modem that is in command mode and the modem echoes the -command or returns a result code. I have heard this sequence can result -in a extended, silly conversation between <tt/getty/ and the modem. - -<sect2><heading>Locked-speed Config</heading> -<p> - -For a locked-speed configuration, you will need to configure the modem -to maintain a constant modem-to-computer data rate independent of the -communications rate. On a USR Sportster 14,400 external modem, these -commands will lock the modem-to-computer data rate at the speed used -to issue the commands: - -<tscreen><verb> -ATZ -AT&B1&W -</verb></tscreen> - -<sect2><heading>Matching-speed Config</heading> -<p> - -For a variable-speed configuration, you will need to configure your -modem to adjust its serial port data rate to match the incoming call -rate. On a USR Sportster 14,400 external modem, these commands will -lock the modem's error-corrected data rate to the speed used to issue -the commands, but allow the serial port rate to vary for -non-error-corrected connections: - -<tscreen><verb> -ATZ -AT&B2&W -</verb></tscreen> - -<sect2><heading>Checking the Modem's Configuration</heading> -<p> - -Most high-speed modems provide commands to view the modem's current -operating parameters in a somewhat human-readable fashion. On the USR -Sportster 14,400 external modems, the command <tt/ATI5/ displays the -settings that are stored in the non-volatile RAM. To see the true -operating parameters of the modem (as influenced by the USR's DIP -switch settings), use the commands <tt/ATZ/ and then <tt/ATI4/. - -If you have a different brand of modem, check your modem's manual to -see how to double-check your modem's configuration parameters. - -<sect1><heading>Troubleshooting</heading> -<p> - -Here are a few steps you can follow to check out the dialup modem on -your system. - -<sect2><heading>Checking out the FreeBSD system</heading> -<p> - -Hook up your modem to your FreeBSD system, boot the system, and, if -your modem has status indication lights, watch to see whether the -modem's <tt/DTR/ indicator lights when the <tt/login:/ prompt appears -on the system's console - if it lights up, that should mean that -FreeBSD has started a <tt/getty/ process on the appropriate -communications port and is waiting for the modem to accept a call. - -If the <tt/DTR/ indicator doesn't light, login to the FreeBSD system -through the console and issue a <tt/ps ax/ to see if FreeBSD is trying -to run a <tt/getty/ process on the correct port. You should see a -lines like this among the processes displayed: - -<tscreen><verb> - 114 ?? I 0:00.10 /usr/libexec/getty V19200 ttyd0 - 115 ?? I 0:00.10 /usr/libexec/getty V19200 ttyd1 -</verb></tscreen> - -If you see something different, like this: - -<tscreen><verb> - 114 d0 I 0:00.10 /usr/libexec/getty V19200 ttyd0 - ^^ -</verb></tscreen> - -and the modem has not accepted a call yet, this means that <tt/getty/ -has completed its open on the communications port. This could -indicate a problem with the cabling or a mis-configured modem, because -<tt/getty/ should not be able to open the communications port until -<tt/CD/ (carrier detect) has been asserted by the modem. - -If you do not see any <tt/getty/ processes waiting to open the desired -<tt/ttyd?/ port, double-check your entries in <tt>/etc/ttys</tt> to -see if there are any mistakes there. Also, check the log file -<tt>/var/log/messages</tt> to see if there are any log messages from -<tt/init/ or <tt/getty/ regarding any problems. If there are any -messages, triple-check the configuration files <tt>/etc/ttys</tt> and -<tt>/etc/gettytab</tt>, as well as the appropriate device special -files <tt>/dev/ttyd?</tt>, for any mistakes, missing entries, or -missing device special files. - -<sect2><heading>Try Dialing In</heading> -<p> - -Try dialing into the system; be sure to use 8 bits, no parity, 1 stop -bit on the remote system. If you do not get a prompt right away, or -get garbage, try pressing <tt><Enter></tt> about once per -second. If you still do not see a <tt/login:/ prompt after a while, -try sending a <tt>BREAK</tt>. If you are using a high-speed modem to -do the dialing, try dialing again after locking the dialing modem's -interface speed (via <tt>AT&B1</tt> on a USR Sportster, for -example). - -If you still cannot get a <tt/login:/ prompt, check -<tt>/etc/gettytab</tt> again and double-check that - -<itemize> -<item> The initial capability name specified in <tt>/etc/ttys</tt> for -the line matches a name of a capability in <tt>/etc/gettytab</tt> - -<item> Each <tt/nx=/ entry matches another <tt/gettytab/ capability -name - -<item> Each <tt/tc=/ entry matches another <tt/gettytab/ capability -name - -</itemize> - -If you dial but the modem on the FreeBSD system will not answer, make -sure that the modem is configured to answer the phone when <tt/DTR/ is -asserted. If the modem seems to be configured correctly, verify that -the <tt/DTR/ line is asserted by checking the modem's indicator lights -(if it has any). - -If you have gone over everything several times and it still does not work, -take a break and come back to it later. If it still does not work, -perhaps you can send an electronic mail message to the &a.questions -describing your modem and your problem, and the good folks on the list will -try to help. - -<sect1><heading>Acknowledgments</heading> -<p> - -Thanks to these people for comments and advice: - -<descrip> - -<tag>&a.kelly</tag> for a number of good suggestions - -</descrip> - - |
