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fioricet online pharmacy Leased line Mini HOWTO Rob van der Putten, rob@sput.nl v2.1, 3 August 2000 Configuring your modem and pppd to use a 2 wire twisted pair leased line. _________ fioricet online pharmacy ____________________________________________________________ Table of Contents 1. Introduction 1.1 Copyright and License 1.2 What is a leased line 1. fioricet online pharmacy Assumptions 2. Modem 2.1 Modem Configuration 2.2 Test 2.3 Examples 2.3.1 Hi-Tech 2.3.2 Tornado FM 228 E 2.3.3 Tron DF 2.3 fioricet online pharmacy 4 US Robotics Courier V-Everything 3. PPPD 3.1 Configuration 3.2 Scripts 3.2.1 Starting the pppd and keeping it alive 3.2.2 Setting the rout fioricet online pharmacy s 3.3 Test ______________________________________________________________________ The most recent (beta) version of this HOWTO can be found at: http://www.s fioricet online pharmacy ut.nl/software/leased-line/ 1. Introduction 1.1. Copyright and License This document is distributed under the terms of the GNU Free Documentation License. Y fioricet online pharmacy u should have received a copy along with it. If not, it is available from http://www.fsf.org/licenses/fdl.html. 1.2. What is a leased line Any fixed, that is p fioricet online pharmacy rmanent, point to point data communications link, which is leased from a telco or similar organisation. The leased line involves cables, such as twisted pair, c fioricet online pharmacy ax or fiber optic, and may involve all sorts of other hardware such as (pupin) coils, transformers, amplifiers and regenerators. This document deals with: fioricet online pharmacy Configuring your modem and pppd to use a 2 wire twisted pair leased line. This document does NOT deal with: SLIP, getting or installing pppd, fioricet online pharmacy synchronous data communication, baseband modems, xDSL. 1.3. Assumptions You should already have a working pppd on your system. You also need Minicom or fioricet online pharmacy a similar program to configure your modems. 2. Modem A leased line is not connected to a telephone exchange and does not provide DC power, dial tone, busy tone fioricet online pharmacy or ring signal. This means that your modems are on their own and have to be able to deal with this situation. You should have 2 identical (including firmware ve fioricet online pharmacy sion) external modems supporting both leased line and dumb mode. Make sure your modems can actually do this! Also make sure your modem is properly documented. fioricet online pharmacy ou also need: · 2 fully wired shielded RS232 cables. The shield should be connected to the connector shell (not pin 1) at both ends (not at one end). · A R fioricet online pharmacy 232 test plug may be handy for test purposes. · 2 RJ11 cords, one for each end of the leased line. · A basic understanding of `AT' commands. 2.1. Modem Confi fioricet online pharmacy uration A note on modem configuration and init strings in general: Configure your modem software such as minicom or (m)getty to use the highest possible speed; fioricet online pharmacy 7600 bps for 14k4 and 115200 bps for 28k8 or faster modems. Lots of people use very long and complicated init strings, often starting with AT&F and containing l fioricet online pharmacy ts of modem brand and -type specific commands. This however is needlessly complicated. Most programs feel happy with the same modem settings, so why not write fioricet online pharmacy hese settings in the non volatile memory of all your modems, and only use `ATZ' as an init string in all your programs. This way you can swap or upgrade your mod fioricet online pharmacy ms without ever having to reconfigure any of your software. Most programs require you to use the following settings; · Fixed baud rate (no auto baud) · Hardw fioricet online pharmacy re bidirectional RTS-CTS flow control (no x-on/x-off) · 8 Bits, no parity, 1 stopbit · The modem should produce the TRUE DCD status (&C1) · The modem should fioricet online pharmacy OT ignore the DTR status (&D2 or &D3) Check this with AT&V or AT&Ix (consult your modem documentation) These settings are not necessarily the same as the defa fioricet online pharmacy lt factory profile (&F), so starting an init string with AT&F is probably not a good idea in the first place. The smart thing to do is probably to use AT&F only fioricet online pharmacy when you have reason to believe that the modem setup stored in the non volatile memory is really screwed up. If you think you have found the right setup for you fioricet online pharmacy modems, write it to non volatile memory with AT&W and test it thoroughly with Z-modem file transfers of both ASCII text and binary files. Only if all of this w fioricet online pharmacy rks perfectly should you configure your modems for leased line. Find out how to put your modem into dumb mode and, more importantly, how to get it out of dumb m fioricet online pharmacy de; The modem can only be reconfigured when it is not in dumb mode. Make sure you actually configure your modems at the highest possible speed. Once in dumb mo fioricet online pharmacy e it will ignore all `AT' commands and consequently will not adjust its speed to that of the COM port, but will use the speed at which it was configured instead fioricet online pharmacy (this speed is stored in a S-register by the AT&W command). Now configure your modem as follows; · Reset on DTR toggle (&D3, this is sometimes a S register). T fioricet online pharmacy is setting is required by some ISP's! · Leased line mode (&L1 or &L2, consult your modem documentation) · The remote modem auto answer (S0=1), the local or fioricet online pharmacy ginate (S0=0) · Disable result codes (Q1, sometimes the dumb mode does this for you) · Dumb mode (\D1 or %D1, this is sometimes a jumper) In dumb mode the fioricet online pharmacy modem will ignore all AT commands (sometimes you need to disable the ESC char as well). Write the configuration to non-volatile memory (&W). 2.2. Test fioricet online pharmacy Now connect the modems to 2 computers using the RS232 cables and connect the modems to each other using a RJ11 lead. Use a modem program such as Minicom (Linux) fioricet online pharmacy procom or telix (DOS) on both computers to test the modems. You should be able to type text from one computer to the other and vice versa. If the screen produc fioricet online pharmacy s garbage check your COM port speed and other settings. Now disconnect and reconnect the RJ11 cord. Wait for the connection to reestablish itself. Disconnect a fioricet online pharmacy d reconnect the RS232 cables, switch the modems on and off, stop and restart Minicom. The modems should always reconnect at the highest possible speed (some mod fioricet online pharmacy ms have speed indicator leds). Check whether the modems actually ignores the ESC (+++) character. If necessary disable the ESC character. If all of this works fioricet online pharmacy ou may want to reconfigure your modems; Switch off the sound at the remote modem (M0) and put the local modem at low volume (L1). 2.3. Examples 2.3.1. Hi-Tec fioricet online pharmacy This is a rather vague `no name clone modem'. Its config string is however typical and should work on most modems. Originate (local): ATL1&C1&D3&L2%D fioricet online pharmacy &W&W1 Answer (remote): ATM0L1&C1&D3&L2%D1S0=1&W&W1 2.3.2. Tornado FM 228 E This is what should work; Originate (local): ATB15L1Q1&C1&D3&L2 fioricet online pharmacy W&W1 Answer (remote): ATM0B15M0Q1&C1&D3&L2S0=1&W&W1 Move the dumb jumper from position 2-3 to 1-2. Due to a firmware bug, the modems will only connect fioricet online pharmacy after being hard reset (power off and on) while DTR is high. I designed a circuit which hard resets the modem on the low to high transition of DTR. The FreeBSD fioricet online pharmacy pppd however, isn't very happy about this. By combining the setting &D0 with a circuit which resets on the high to low transition instead, this problem can be av fioricet online pharmacy ided. 2.3.3. Tron DF The ESC char should be disabled by setting S2 > 127; Originate: ATL1&L1Q1&C1&D3S2=171\D1&W Answer: ATM0&L2Q1&C1&D3S0= fioricet online pharmacy S2=171\D1&W 2.3.4. US Robotics Courier V-Everything The USR Sportster and USR Courier-I do not support leased line. You need the Courier V-everything version f fioricet online pharmacy r this job. There is a webpage on the USR site `explaining' how to set-up your Courier for leased line. However, if you follow these instructions you will end u fioricet online pharmacy with a completely brain dead modem, which can not be controlled or monitored by your pppd. The USR Courier can be configured with dip switches, however you nee fioricet online pharmacy to feed it the config string first. First make sure it uses the right factory profile. Unlike most other modems it has three; &F0, &F1 and &F2. The default, w fioricet online pharmacy ich is also the one you should use, is &F1. If you send it an AT&F, however it will load the factory profile &F0! For the reset on DTR toggle you set bit 0 of S register 13. This means you have to set S13 to 1. Furthermore you need set it to leased line mode with &L1; ATS13=1&L1&W The dip switches are all default except for the following: 3 OFF Disable result codes 4 ON Disable offline commands 5 ON For originate, OFF For answer 8 OFF Dumb mode 3. PPPD You need a pppd (Point to Point Protocol Daemon) and a reasonable knowledge of how it works. Consult the relevant RFC's or the Linux PPP HOWTO if necessary. Since you are not going to use a login procedure, you don't use (m)getty and you do not need a (fake) user associated with the pppd controlling your link. You are not going to dial so you don't need any chat scripts either. In fact, the modem circuit and configuration you have just build, are rather like a fully wired null modem cable. This means you have to configure your pppd the same way as you would with a null modem cable. For a reliable link, your setup should meet the following criteria; · Shortly after booting your system, pppd should raise the DTR signal in your RS232 port, wait for DCD to go up, and negotiate the link. · If the remote system is down, pppd should wait until it is up again. · If the link is up and then goes down, pppd should reset the modem (it
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