From: bmehlman@trirex.COM (Ben Mehlman)
Newsgroups: rec.radio.amateur.packet
Subject: SLIP - What is (answer) - NOS versions, 'dialer', SLIP timeout., finger (questions) Thanks!
Date: 5 Jan 93 01:43:15 GMT
Organization: UCSD Usenet Gateway
NNTP-Posting-Host: ucsd.edu
Originator: daemon@ucsd.edu

An Answer

Rainer:

SLIP stands for Serial Line Internet Protocol.  Basically, it's a  
protocol used for connecting two ip (Interrnet Protocol) based boxes  
via a dedicated or dial up serial connection.  The boxes could be   
unix machines, routers, or chameleons such as the KA9Q NOS.

There is a SLIP protocol module built in to the KA9Q NOS.

So for example you could network two machines together by putting a  
null-modem cable between them and running SLIP protocol software on  
both machines.  More likely you'd put (wireline) modems on the  
machines and allow them to network across some distance via ma bell.

PPP (Point to Point Protocol) is another protocol used for the same  
purposes, but with some additional features that make it more  
suitable for dial-up use.

A few questions

I am trying to set up dial-in and dial out SLIP on my KA9Q NOS box.   
On the dial in, I have one problem to solve, which is that I want the  
modem to hang up on the caller if there is no activity on the port  
for a few minutes.  I don't think the NOS is equipped to do this.  My  
solution so far is to bastardize the 'dialer' code to create a  
'watcher'.  The watcher watches for data transmissions and carrier  
status on a port.  If CD stays true for XX time without any activity,  
it (depending on how ambitious I get) drops DTR fora couple of  
seconds or executes a hangup script.

I was wondering: has anyone else has approached this problem, and how  
did you solve (or fail to solve) it?

The other problem I'm having is generally related to using 'dialer'  
to dial a slip connection.  First of all, all the docs I have  
indicate a different version of dialer than the executable.  The  
executable is asking me for an interface, timeout, raise script, and  
lower script.  I tried to use this but could not get it to dial or  
generate any errors (once I has all the files in place and the flags  
set on the asy attach).

The port DOES work and I am able to tip out through it.  I am going  
to try a manually initiated slip tonight.

All the docs I have talk about a dialer that asks for number of pings  
etc and uses one script.

I've been looking at the source and it seems to have been modified  
several times...  The last mod was in mar '92 by PK.

Anyway, there are two things I am trying to accomplish re dialing: 


1 - Keep a line up, ie dial a connection to another site and keep it  
going, redialing automatically if the link should drop.  The version  
of 'dialer' described in my docs seems like it is written  
specifically for this purpose.

2 - Demand dial a line, ie when I try to send a packet through that  
port, if the connection is down it dials.  If the connection should  
be terminated (ie ma bell gives up or the other side times out), my  
side does nothing unless another packet is sent.  I was also thinking  
another that a timeout on my end would be nice, ie set a maximum time  
that my end will keep the connection going in the absence of traffic.

I have no idea whether there is anything written for NOS to do #2.

Another question:  What is the difference between the current KA9Q  
release of NOS and the version maintained by PA0GRI?

Re: finger and fingerd
I am having a problem with finger where I can finger the NOS box from  
my unix box, and get the system info and a list of all 'users' ie  
files in /nos/cfg/finger (on my system \nos\cfg is passed to  
net.exe).  However, when I try to finger a particular user it says  
'user not known'.  I was wondering if I am doing something really  
dumb.  I also have those same users listed in my ftpusers file.

In the source I have, you cannot finger someone on your own machine.   
I was wondering if there is any reason why one couldn't modify finger  
to assume the local hostname where none is supplied.  The finger  
session could then access fingerd on the same machine??  I could even  
see cheating by looking up the local ip address directly rather than  
requiring an entry in the hostname table.  I was wondering if there  
is a KA9Q sockets or pre-emption caveat that makes this impossible.   
Is it not cool to connect to a socket on the same NOS machine in  
general??

Thanks! very much to all who have been helping me with this, and  
sorry! to the dozen or so who wrote to me asking for forwarding of  
information.  I just can't get to all of you right now, but I intend  
to summarize my whole setup and what I did to get it working as soon  
as I DO get it working :)  I don't want to spread misinformation...

I DO have it working on ethernet and I'm working on SLIP now, plus  
trying to learn about all the various services NOS provides and how  
to set them up.  I don't have my packet modem yet...  If you are  
interested in talking about any of the stuff I've mentioned, feel  
free to contact me via home telephone, 203-866-9515.  This is the  
only practical way to carry on a lengthy conversation with me right  
now as I am very busy at work... 


I would especially like to hear from people who are using the GRAPES  
modem and/or using NOS to bridge land-based networks of unix or  
novell boxes.

Thanks and 73, 


Ben KB2ERP
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