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1992-06-23
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UK AMPRNET TCP/IP Newsletter
Mike Chace - G6DHU
Issue 2 Volume 1 - March 1991
1. Introduction
Hello and welcome to the second issue of this newsletter. I
had a great response to the first issue and so I've decided
to carry on as before.
If you're reading this for the first time perhaps I ought to
explain what the newsletter is all about...
With the number of amateurs now using TCP/IP software on
packet radio rising steadily, I thought that we needed a
newsletter to help us keep up to date with matters such as
new software releases, TCP/IP network information, beginners
help and interlinking of IP 'clusters'. The newsletter
appears bi-monthly, distributed through the national mailbox
network addressed to the TCP/IP community (TCPIP @ GBR). If
you have an Internet/JANET connection at your work then I
can mail the newsletter to you that way.
The format is largely down to me at the moment and I'm
always happy to include topics that YOU want to see
included!
If you are a beginner, perhaps thinking of starting out on
TCP/IP, perhaps I should say that my beginners information
package is still available (see below). Also, if you
missed the first issue of the newsletter, I'm happy to
include the previous copies on disk.
Anyway, on with the important business....
2. Beginners Matters
Getting Your IP Address
Each TCP/IP user is identified by their IP address, a unique
number. These addresses are allocated by an administrator
who does this on a country wide basis. Our IP address
co-ordinator is Dave Lockwood (G4CLI) who can be contacted
at GB7YAX.
If you are starting out on TCP/IP you will need an address.
The best way to go about this is to apply for your address
by sending Dave some mail with the following information :-
Your Full Name and Callsign
Your Postal Address (especially your postal town)
Your IARU QTH Locator
Your local Mailbox
You might also like to include details of the equipment that
you are thinking of using.
Within a short while you will receive your address.
Obviously, in the meantime you'll probably want to get
going on the air with a temporary address while you wait
for your proper one. Temporary address allocation is best
handled by contacting your local IP group who'll always be
happy to set you up.
A short note: Dave recently suffered a break-in and this
will obviously affect his speed in processing new address
requests. SO BE PATIENT and use a temporary address in the
meantime!
3. Some Beginners Questions
One of my local stations recently made the jump to TCP/IP
using his Amiga machine which runs a version of the NOS
(Network Operating System) software. He sent me a selection
of questions which were causing him some concern before he
eventually started up on TCP/IP. Since these are pretty
common questions I'm sure that they will be of help to many
of you considering IP.
1. Can I still monitor normal ax25 when using TCP/IP?
Yes, you can. In fact the monitor facility in all
versions of TCP/IP software (called 'trace') will
decode and display all currently known protocols
used in packet radio eg. NET/ROM, TCP, IP, ARP
and normal AX25.
All TCP/IP software still allows you to connect to
other AX25 (TNC) users and them to connect to
you. In fact, NOS software provides a BBS like
interface to all users which allows people to
send/list mail, connect to other TCP/IP stations,
connect to your NET/ROM node and upload/download
files. So you won't lose touch with your chums
still on AX25 Level2!
2. Will my ax25 mailbox still work?
Yes it will but of course the mailbox is a bit
different from those seen in TNC firmware. All
TCP/IP software versions have a mailbox from which
other users can send you mail. They also allow a
local BBS to forward mail to you and for you to
forward mail (personal and bulletins) from TCP/IP
to either your local BBS or to normal TNC
PMS/PBBSs.
3. Can I still work non-TCP/IP stations - do I have to
keep changing from one mode to another?
Yes you can. All TCP/IP software will allow you
to hold multiple simoultaneous conversations in
more than one mode.
For instance, you can be talking to another local
IP station, a local AX25 user's TNC and making a
NET/ROM connect to your local node - all at the
same time. While this happens some one could be
sending you mail, downloading a file to you - all
handled 'in the background' by your machine.
4. What about connecting to my local GB7___ BBS - can I
still do this?
Yes. I mentioned earlier that you can have all you
mail automatically sent to/from your TCP/IP BBS
too. But you can still connect to the mailbox
just as you did with your TNC.
5. What sort of machine will TCP/IP software run on and
do I need any other hardware ?
TCP/IP runs on most 16bit computers. The Atari
ST, Commodore Amiga, Apple Macintosh and the PC
clones will all run TCP/IP. You will need a
minimum of 512k bytes of memory in your machine to
run TCP/IP satisfactorily.
The programs are Public Domain and therefore
FREE.
There is no other hardware needed apart from your
normal TNC - as long as it supports the KISS
firmware (look it up in your TNC manual).
6. What functions is the tnc performing in kiss mode?
KISS firmware takes over the control of your TNC
(So your normal firmware functions eg PMS won't be
available).
KISS basically forms a simple interface between
your computer's RS232 link and the airwaves. Your
machine wraps up packets to be sent in a simple
serial 'packet' and sends them to the TNC. The
KISS TNC software 'unwraps' the serial packet and
makes up the HDLC frame to be sent out over the
air from it.
The receive process is much the same but the host
computer decodes all the data in the KISS
packet. It is this simple interface that gives
the host computer the power to hold conversations
in any protocol necessary.
Perhaps I should also stress that NO modifications
are necessary to either your computer OR radio in
order to run TCP/IP.
7. If most of the work is being done by the computer,
is it feasible to home brew a kiss mode tnc?
Yes. For instance, the G0BSX homebrew TNC design
can be equipped with a KISS only ROM to provide
your interface. If you run a NET/ROM node, TCP/IP
software supports the NRS (NET/ROM Routing Server)
protocol, so you can connect a TCP/IP node to
your NET/ROM node via the TNC serial port.
8. How much activity is there on TCP/IP?
Quite a lot and it's growing all the time as 16bit
computers become cheaper. There are some 600
allocated TCP/IP addresses, about half of which
are stations on-air 24 hours. Activity tends to
be in pockets, obviously increasing around the
major towns but there are enough TCP/IP stations
now for at least one to be within a few miles of
most of us.
You could always look on your local node for nodes
with an SSID of -5 or an alias of IPxxxx or TCPxxx
which will probably indicate the NET/ROM node port
of a TCP/IP system. Alternatively, switch
'monitor' on while on 144.625MHz and if you
receive lots of 'garbled' packets, this probably
indicates local IP traffic.
If you are interested, why not put a message on
your local mailbox and ask if there are any local
IP stations!
9. What advantages/disadvantages does TCP/IP offer?
There's not a lot of space for this one but here
are some....
Your computer becomes part of an integrated
(and cooperating) network. It can perform
packet switching operations (in all modes) as
well as being a 'user end-point'.
Your machine can converse in all the current
protocols and provides other users with an
interface for using them eg mailbox, NET/ROM
node, gateways etc.
TCP/IP has a number of standard 'services'
available to you and anyone using your
station. FTP for transferring files
(binaries and text), SMTP for the automatic
sending and receiving of TCP/IP mail, TELNET
for TCP/IP keyboard to keyboard chats, NNTP
for news distribution etc.
As well as providing all the facilities you
would expect for your own use, TCP/IP makes
them available for any other IP station. The
software handles packet switching, file
transfers, mail routing on behalf of other
stations automatically and transparently
while you get on with what you want to do.
10. I have the program - it all looks terribly
complicated - there are 101 commands - just how easy is
it to get it all going?
Admittedly, this is one of the difficult parts to
"taking the plunge". Yes, there are a lot of
commands but you can get by with a few at first
and build up your knowledge as you use the program
and read the documentation and help provided.
Most distribution disks come with much
documentation and help on installing the program
and getting it running. Obviously, you have to do
some 'fine-tuning' such as callsigns etc but
again the set-up files usually tell you how to do
it.
As usual, there's no substitute for READING the
documentation and if you do get stuck there is
nearly always help available from local IP
stations or via the national mailbox network
(TCPIP@GBR).
4. Interference Claims and other Myths
A number of interested beginners have written to me
mentioning that they have been discouraged by their local
nodeops, sysops and AX25 users from using TCP/IP on the
grounds of both network congestion and 'interference'. So
let's consider these points - you might well be accused
yourself!
Admittedly TCP/IP sometimes sends long packets and so adds
to network congestion a little. However, running a KISS
based system means that your system makes better use of the
channel by using proper slotted access and engaging
p-persistance timing (look it up in your TNC manual).
Obviously the TCP/IP users have an obligation to keep
packets as small as possible and all distribution software
does this. AX25 users are just as much to blame if they run
with large MAXFRAME values, long packets and FRACK timing.
TCP/IP causes interference. Wrong!
TCP/IP uses the services of AX25 and NET/ROM to send it's
packets and so there is no way that using TCP/IP on the same
channel can cause 'interference'. There are a number of
things that you can tell your local AX25 users if they
complain of corruption of their terminals etc when
monitoring TCP/IP traffic on the channel. Tell them to
switch in their TNC 'protocol filter'. Most TNCs have one
called either MPROTO or PIDCHECK. Switching this on will
make their TNCs ignore any packets that have a
'higher-level' protocol (eg NET/ROM, IP etc). That way,
their monitors won't crash.
You can't run TCP/IP on 144.675 or 144.650. Wrong!
I know 144.625 is set aside for real-time and TCP/IP traffic
but some of us (myself included) have no well enough
connected 144.625 network and so we must use one of the
other channels. As I said before, sending TCP/IP traffic on
any channel WILL NOT interfere with existing users.
Obviously, we all have to be sensible about these matters as
we all have to co-exist. Once the IP network expands we can
all move off to channels such as 144.625.
5. Software News - New Releases
PE1CHL NET Version 9101 - Atari ST, PC clones and Xenix
systems.
A new release of this software is immenent featuring :-
NET/ROM Source Quench
Support for the PACSAT (Packet Satellite) protocol
stack
Updated mailbox
Improved session control
This software is available from Paul (G1PLT) who can be
contacted at the GB3XP Mailbox and QTHR. I'm willing to help
users of this software but please DON'T contact me for
copies of the software!
G1EMM NOS 901130 v1.6 - PC clones
The new release of Kelvin Hill's program features
NNTP (Network News Transfer Protocol) support
New set of packet hardware device drivers
Mailbox capable of forwarding to/from PMS/PBBSs and
local BBSs
This software is available from Kelvin (G1EMM - QTHR) at
GB7WOK and he is also willing to help users get going with
his excellent software.
Amiga NOS Version 2.6 - Commodore Amiga
John (G1YYH) has enhanced this version of NOS for the Amiga
series of machines. The software is available from him (via
GB7NWP).
G6DHU TCP/IP Beginners Documentation Package.
This package is distributed by myself on a 3.5 inch floppy
in Atari ST or IBM-PC (MSDOS 720k) formats. The package has
been updated to include three more articles and manuals
(below) of interest to all TCP/IP users or beginners.
NET/ROM User Manual by W9NK
NOS Mailbox Manual by SM0RGV et al
RSPF Defining Document by K1IO
MSYS TCP/IP and BBS System Version 1.11 - PC clones
I hear from the Internet that there is a new version of this
BBS program with TCP/IP support following hot on the heels
of v1.10. I'd welcome any reports from users of this
software.
NOS - Apple Macintosh
Again, I'd like some user reports of this software. The
software is available but apart from that I don't know much
more!
If you do decide to send disks to the above mentioned PLEASE
remember to include return postage and your address.
6. TCP/IP Network Development
This section of the newsletter is devoted to matters
concerning local TCP/IP networking and exists to keep TCP/IP
users informed of changes and additions to the network.
Firstly, thanks to Paul (G0MHD @ GB7KHW) for a description
of his local IP network in and around the Cambridgeshire
area.
To give you a clue there is a central NET Node in Cambridge,
GB3PX. This node connects the following:
GB7PX 23cm trunk link, this connects to G0DDX-8 NETROM,
GB7DDX BBS located in Cambridge, G4UXV-8 NETROM, GB7HXA BBS
located in Huntingdon, GB7WNM +NODE located in Kings Lyn,
all these connections are first class and should be
considered practical.
GB3PX is a 2 meter node on 144.650 and is hard wired to
GB7PX which is 23cm.
G0DDX-8 has the following frequencies: 23cm, 70cm 432.675,
2m 144.650, 4m.
G4UXV-8 has the following frequencies: 23cm, 70cm 432.675,
2m 144.650, 6m.
There are as you might imagine many more further connections
from this group. Places like Northampton. Saffron Walden
and Peterborough to name a few.
The local TCP/IP group uses 2 meters (144.625) and is almost
isolated from the rest of the NTS/NETROM system. The
gateway for mail is GB7KHW and this station uses Msys. His
Netrom node is switched off at the present time for reasons
which I fully understand. I run NOS which is running behind
a G8BPQ node and supports two frequencies, 144.625 and at
the present time 70cm, attended only, on 432.675. This
provides an excel- lent gateway into the main network in
this area. I hope to change the 70cm port to 23cm in the
future. I had better point out that all the 23cm links in
this area are 9600 baud and are can handle more load than
the conventional 1200 baud links. My link to GB3PX is via
G0DDX-8.
Thanks Paul for that description. So if you're a newcomer
to TCP/IP in Paul's area - you know who to contact!
Bath and Bristol Subnet
Since the last newsletter my own subnet has joined up with
other TCP/IP nodes further North. Believe it or not we now
have a reliable link from Bristol to Sheffield via Sutton
Coldfield and Birmingham and West into Wales. The topology
looks something like the following.
Bath and Bristol (subnet 20) (6 users - most 24 hour)
|
TCPWRW:G4WRW-4 ------------- SGLAM:GW3NYY-5
| (S. Wales)
|
|
TCPAMD:G8AMD-5 Sutton Coldfield
|
|-------------G7BGP Birmingham
|
|
TCPBSX:G0BSX-2 Sheffield
As you can see from the map above, it is possible to link up
IP nodes over long distances and over busy NET/ROM
networks. Obviously with round trip times of some 200
seconds end-to-end, the link isn't good enough for chats but
mail finds it's way along nicely. We are currently looking
at the possibility of links to London and Oxfordshire which
as you can see will be a great step forward for the UK
AMPRNet.
As I mentioned in the last newsletter, please send in your
reports of local activity, even if you are isolated. Your
report might start another group thinking about linking up
to you.
7. Beginners' Tutorials
I'm aware that there are a few gaps in the existing TCP/IP
documentation that could be filled with some tutorials.
Springing to mind come ARP, IP routing using NET/ROM and the
OSI Reference Model. The first topic (ARP) seems to be the
most mis-understood and I've begun work on a tutorial to be
sent out later some time.
If anyone else would like to suggest areas for improvement
please drop me a line or give me a ring and we could sort
something out.
And you beginners out there ? Send in your requests for
discussion topics and articles (See my address at the end of
the newsletter).
8. 221 Closing....
Last but not least, thanks to all those who responded to my
last newsletter...
G0's IYJ, MHD, LCE, LXC
G1's FDK, WIK, PLT
G3's KFN, RPI
G4's WRW, OTJ, JQD, NUB, OOS, DJD, BBH, ZKK, YLJ
G6's KVK, HUJ
G7's EXU, FTO
G8's XAN, ASO, GGI
GM4YED, GM4JJJ, GM4WMN
GW4NNL, GW3NYY
Please send suggestions and articles for inclusion to me at
the following addresses ;
84 Frankland Close
Bath
Avon
BA1 4EL
or via e-mail (mikec@praxis.co.uk), AMPRNET g6dhu.ampr.org
[44.131.20.3] or AX.25 NTS BBS (G6DHU@GB7IMB).
I can accept material on 720k IBM/MS-DOS and Atari ST 3.5
inch format disks and if you want them back PLEASE include
the return postage.
All material greatfully received!
73 until next time, Mike.