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1994-11-27
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Subject: TCP/IP: Pings, POPs and KISSes
If you're an active packeteer, sooner or later someone will bring up the
subject of TCP/IP--Transmission Control Protocol/Internet Protocol. Of
all the packet networking alternatives used on the air today, TCP/IP is
the most popular.
Despite its name, TCP/IP is more than two protocols; it's actually a set
of several protocols. Together they provide a high level of flexible,
"intelligent" packet networking that isn't possible with AX.25. At the
time of this writing, TCP/IP networks are local and regional in nature.
For long-distance mail handling, TCP/IP still relies on traditional
AX.25 NET/ROM networks. Even so, TCP/IP enthusiasts see a future when
the entire nation, and perhaps the world, will be linked by high-speed
TCP/IP systems using terrestrial microwave and satellites.
Sending Mail with TCP/IP
With TCP/IP you can send local and regional mail efficiently and
reliably. You need only prepare the message and leave it in your own
TCP/IP "mailbox." Within seconds your computer will attempt to make a
connection to the target station and deliver the message directly. There
are no PBBSs involved. The message packets simply travel through the
network until they reach the other station. While this is taking place,
you can talk to, or receive mail from, another station. If you're
fortunate enough to own Windows, DESQview or similar multitasking
software, you can leave the TCP/IP program entirely and play a game or
write a letter while your message is being delivered!
Before sending a message to another station, it's possible to use TCP/IP
to see if the station is actually on the air. You use the ping function,
which stands for Packet Internet Groper. I like to think of it as the
sonar pings used by ships and submarines to find out what's in the water
around them. It works in nearly the same manner, but it's much more
specific! If I want to find out if WS1O is available on the network, I
just ping him as follows:
ping ws1o
Note that TCP/IP is case sensitive. That is, the use of upper- or lower-
case letters is important. Most TCP/IP commands are lower-case.
If WS1O has his station on the air, I'll see:
44.88.0.23: echo reply id 0 seq 61531, 7000 ms
This cryptic line merely confirms that WS1O is on the air. His TCP/IP
address is shown (44.88.0.23) along with the time it took to send the
ping from my station to his (7000 ms or 7 seconds). It lets me know that
the mail I send now will arrive at his station within a reasonably short
period of time.
If you want to send mail to hams in cities outside your TCP/IP network,
you'll need to post it on an AX.25 bulletin board. Some AX.25 PBBSs
feature special ports that allow TCP/IP users to connect to the system.
If your local PBBSs doesn't have a TCP/IP port, don't worry. Your TCP/IP
software provides a means to communicate with AX.25 stations (and vice
versa). As TCP/IP networks expand, you'll be able to reach hams in
distant cities without having to resort to the AX.25 mail forwarding
system.
What if someone tries to send mail to you when you're not on the air? If
they can't connect to your station, their computer will hold the message
and try again later. Many TCP/IP packeteers also use Post Office
Protocol (POP) servers to hold incoming mail when they're not on the
air. When they activate their stations, the TCP/IP software sends an
inquiry to the POP server to see if any mail is waiting. If mail is
available, it's transferred automatically!
Shooting the Breeze with TCP/IP
Talking to another station on a NET/ROM network can be a difficult
proposition--especially if the station is distant. You can only hope
that all the nodes in the path are able to relay the packets back and
forth. If the one of the nodes becomes unusually busy, your link to the
other station could collapse. Even when the path is maintained, your
packets are in direct competition with all the other packets on the
network. With randomly calculated transmission delays, collisions are
inevitable. As a result, the network bogs down, slowing data throughput
for everyone.
TCP/IP has a unique solution for busy networks. Rather than transmitting
packets at randomly-determined intervals, TCP/IP stations automatically
adapt to network delays as they occur! As network throughput slows down,
active TCP/IP stations sense the change and lengthen their transmission
delays accordingly. As the network speeds up, the TCP/IP stations
shorten their delays to match the pace. This kind of intelligent network
sharing virtually guarantees that all packets will reach their
destinations with the greatest efficiency the network can provide.
With TCP/IP's adaptive networking scheme, you can chat with a ham in a
distant city and rest assured that you're not overburdening the system.
Your packets simply join the constantly moving "freeway" of data. They
might slow down in heavy traffic, but they will reach their destination
eventually. (This adaptive system is used for all TCP/IP packets, no
matter what they contain.) If you want to check the status of your
target station--and the path between--just use the ping function as we
discussed earlier.
Swapping Files via TCP/IP
TCP/IP really shines when it comes to transferring files from one
station to another. By using TCP/IP, you can connect to another station
and transfer computer files--including software. As you can probably
guess, transferring large files can take time. With TCP/IP, however, you
can still send and receive mail or talk to another ham while the
transfer is taking place!
To transfer a file from one station to another, you use the File
Transfer Protocol, or FTP. We already know that WS1O is on the air.
Let's set up an FTP link with his computer and grab a file.
ftp ws1o
When the link is established, my terminal displays:
SYN sent
Established
220 ws1o.ampr.org FTP version 890421.1e ready at Sat Aug 13
18:22:26 19
Now I'm ready to log in. At the command prompt I send: user anonymous.
My terminal displays WS1O's response.
331 Enter PASS command
No problem. Most systems allow you to use your call sign as the
password.
pass wb8imy
When I see 230 Logged in, it's time to check his computer to see what he
has to offer. All I have to do is send dir and my screen displays:
200 Port command okay 150 Opening data connection for LIST\public
switch.map 1,500 19:57 06/19/92
tcp/ip.doc 10,000 02:30 07/01/92
space.exe 20,000 22:25 07/16/92
3 files 13,617,152 bytes free. Disk size 33,400,832 bytes
Get complete, 200 bytes received
Whew! It looks complicated at first glance, doesn't it? All it's telling
you, though, is that WS1O has three files available for transfer. The
name of each file is shown along with its size and the date it was
placed on his disk. If you have some experience with computers, this may
look familiar. (You've just issued the "directory" command that's common
to most machines.)
I happen to know that "space.exe" is a game that WS1O has written for my
particular computer. Regardless of whether it's an ASCII or binary file,
I can transfer a copy by simply using the get command.
get space.exe
In response, I'll see:
200 Port command okay
150 Opening data connection for RETR space.exe
As I've already pointed out, the transfer may take several minutes,
especially if WS1O is distant or the network is busy. hat's okay because
I can spend the time sending mail to other amateur friends in the area.
When the transfer is complete, my screen displays:
Get complete, 20,000 bytes received
226 File sent ok
Great! The transfer was a success. I can send a file to his
station using the put command, or I can close the link and go play the
game!
FIN wait 1
Time wait
Closed (Normal)
TCP/IP Switches
Most TCP/IP networks depend on dedicated switches to move data through
the system. NET/ROM nodes are also used when necessary. Like NET/ROM
nodes, TCP/IP switches communicate with each other over high-speed
backbone links on the 222- or 420-MHz bands.
Many TCP/IP packeteers access their local switches on the 2-meter band
with 144.91 MHz being a popular frequency. Access on 2 meters currently
takes place at a data rate of 1200 bit/s. However, TCP/IP switches use
backbone links to relay data throughout the network at rates of 9600
bit/s or higher.
When you try to contact another station using TCP/IP, all network
routing is performed automatically according to the TCP/IP address of
the station you're trying to reach. In fact, TCP/IP networks are
transparent to the average user. Your packets may flow back and forth
through several switches and you won't even know it!
On conventional NET/ROM networks, access to backbone links is
restricted. This isn't true on TCP/IP. Not only are you allowed to use
the backbones, you're actually encouraged to do so! If you have the
necessary equipment to communicate at the proper frequencies and data
rates, you can tap into the high-speed TCP/IP backbones directly. By
doing so, you'll be able to handle data at much higher rates. This
benefits you and everyone else on the network.
What Do I Need to Run TCP/IP?
You'll be pleased to know that you can join the TCP/IP community with
the packet equipment you probably own already. In terms of hardware, all
you need is a computer (it must be a computer, not a terminal), a 2-
meter FM transceiver and a TNC with KISS capability.
What in the world is KISS? KISS stands for Keep It Simple, Stupid and
most modern TNCs and MCPs have this feature. When you place your TNC in
the KISS mode, you disable the AX.25 protocols and reduce the unit to a
basic packet modem. All of the incoming and outgoing data will be
processed directly by your computer, not your TNC.
As you might guess, the heart of your TCP/IP setup is software. The
TCP/IP software set was written by Phil Karn, KA9Q, and is called NOSNET
or just NOS. The program is available for IBM-PCs and compatibles, Apple
Macintoshes, Atari STs and Commodore Amigas. NOS takes care of all
TCP/IP functions, using your "KISSable" TNC to communicate with the
outside world.
The only other item you need is your own IP address. Individual IP
Address Coordinators assign addresses to new TCP/IP users. All you have
to do is contact the coordinator in your area.
It sounds almost too simple, doesn't it? Well, learning a new protocol
such as TCP/IP presents a challenge to some. There's a completely
different set of abbreviations and "buzz words" that you'll need to
know. It also takes some time to completely set up the NOS software and
get it running properly. Most experienced TCP/IP users are more than
glad to help you solve any problems. -- WB8IMY
AMPRNet IP address coordinators as of 29 Jan 1994
Corrections and updates to brian@ucsd.edu.
The people listed here have volunteered to issue IP addresses for
their areas. They aren't paid to do this service; please understand
that they are perfectly at ease to deal with coordination responses
at a lower priority than the things that matter more, such as job
and family. Please be patient when requesting an address.
44.002 Bob Meyer K6RTV CA: Sacramento
44.004 Douglas Thom N6OYU CA: Silicon Valley -
San Francisco
44.006 Don Jacob WB5EKU CA: Santa Barbara/
Ventura
44.008 Brian Kantor WB6CYT CA: San Diego
44.010 Terry Neal AA6TN CA: Orange County
44.012 Steven King KD7RO E WA, IDo
44.014 John Shalamskas KJ9U HI & Pacific Is
44.016 Jeff Angus WA6FWI CA: Los Angeles -
S F Valley
44.017 Dana Myers KK6JQ CA: Antelope Valley/
Kern County
44.018 Geoffrey Joy KE6QH CA: San Bernardino &
Riverside
44.020 Fred Schneider K0YUM CO: Northeast
44.022 John Stannard KL7JL AK
44.024 Dennis Goodwin KB7DZ W WA state: Puget
Sound
44.026 Ron Henderson WA7TAS OR
44.028 Don Adkins KD5QN N TX
44.030 J Gary Bender WS5N NM
44.032 Bdale Garbee N3EUA CO: Southeast
44.034 Mark J. Bailey N4XHX TN
44.036 Doug Drye KD4NC GA
44.038 Mike Abbott N4QXV SC
44.040 Matt Simmons KG7MH UT
44.042 John Martin KB5GGO MS
44.044 Bob Wilson KA1XN W MA
44.046 Stan Wilson AK0B MO
44.048 Jacques Kubley KA9FJS IN
44.050 Ron Breitwisch KC0OX IA
44.052 Gary Grebus K8LT NH
44.054 Ralph Stetson KD1R VT
44.056 Johnathan Vail N1DXG E & Central MA
44.058 Rich Clemens KB8AOB W VA
44.060 Howard Leadmon WB3FFV MD
44.062 Jim DeArras WA4ONG VA
44.062 Jon Gefaell KD4CQY VA (Charlottesville
area)
44.064 Dave Trulli NN2Z N NJ
44.065 Bob Applegate WA2ZZX S NJ
44.066 John DeGood NU3E DE
44.068.1-32 Bob Foxworth K2EUH NYC & LI
44.068.64+ Bob Bellini N2IGU ENY
44.069 Paul Gerwitz WA2WPI WNY
44.070 Gary Sanders N8EMR OH
44.072 Ken Stritzel WA9AEK Chicago - N IL
44.073 Chuck Henderson WB9UUS S/Central IL
44.074 Mark Bitterlich WA3JPY NC E
44.075 Charles Layno WB4WOR NC W
44.076 Kurt Freiberger WB5BBW S TX
44.077 Rod Huckabay KA5EJX W TX
44.078 Joe Buswell K5JB OK
44.080 Doug Crompton WA3DSP E PA
44.082 Steven Elwood N7GXP MT
44.084 Bob Ludtke K9MWM CO: Western
44.086 Reid Fletcher WB7CJO WY
44.088 Bill Lyman N1NWP CT
44.090 Mike Nickolaus NF0N NE
44.092 Pat Davis KD9UU WI, upper peninsula MI
44.094 Gary Sharp WD0HEB MN
--- Andy Warner N0REN (Minn-Twin Cities area
only)
44.096 Don Bennett K4NGC DC
44.098 Bruce La Pointe WD4HIM FL
44.100 Richard Elling KB4HB AL
44.102 Jeff King WB8WKA MI lower peninsula
44.104 Charles Greene W1CG RI
44.106 Tyler Barnett N4TY KY
44.108 James Dugal N5KNX LA
44.110 Richard Duncan WD5B AR
44.112 Bob Hoffman N3CVL W PA
44.114 Steven Elwood N7GXP ND & SD
44.116 Tom Kloos WS7S OR: NW & Portland,
Vancouver WA
44.118 Carl Ingerson N1DXM ME
44.120 unassigned
44.122 Dale Puckett K0HYD KS
44.123 Bernie McDonnell NP2W Virgin Is
44.124 David Dodell WB7TPY AZ
44.125.0-126 Earl Petersen KF7TI S NV
44.125.128-254 Bill Healy N8KHN N NV
44.126 Karl Wagner KP4QG PR
#
# 44.128 is reserved for testing. Don't use for operational networks.
# You may safely assume that any packets with 44.128 addresses are
# bogons unless you're using them for some sort of testing
#
44.128 TEST
#
# International subnet coordinators by country
#
44.129 Japan JG1SLY Tak Kushida,
JH3XCU Joly Kanbayashi
44.130 Germany DL4TA Ralf D Kloth
44.131 United Kingdom G1PLT Paul Taylor
44.132 Indonesia YB1BG Robby Soebiakto
44.133 Spain EA4DQX Jose Antonio Garcia. Madrid.
(EA4DQX @ EA4DQX)
44.134 Italy I2KFX
44.135 Canada VE3JF Barry McLarnon
44.136 Australia VK2ZXQ John Tanner
44.137 Netherlands PA0GRI Gerard Van Der Grinten
44.138 Israel 4X1GP Peleg Lapid
44.139 Finland OH1MQK Matti Aarnio
44.140 Sweden SM0IES Lennart
44.141 Norway LA4JL Per Eftang
44.142 Switzerland HB9CAT Marco Zollinger
44.143 Austria OE1KDA Krzysztof Dabrowski
44.144 Belgium ON7LE
44.145 Denmark OZ1EUI
44.146 Phillipines DU1UJ Eddie Manolo
44.147 New Zealand ZL2BKC Wayne Knowles
44.148 Ecuador HC5K Ted
44.149 Hong Kong VS6YHJ Thomason FAN
44.150 Slovenija S53FK Iztok Saje
44.151 France FC1BQP Pierre-Francois Monet
44.152 Venezuela OA4KO/YV5 Luis Suarez
44.153 Argentina LU7ABF Pedro Converso
44.154 Greece SV1UY Demetre Valaris
44.155 Ireland EI9GL Paul Healy
44.156 Hungary HA5DI Bela Markus
44.157 Chile CE6EZB Raul Burgos
44.158 Portugal CT1DIA Artur Gomes
44.159 Thailand HS1JC Kunchit Charmaraman
44.160 South Africa ZS6BHD John
44.161 Luxembourg LX1YZ Erny Tontlinger
44.162 Cyprus 5B4TX C. Costis
44.163.16 Panama
44.163.32 Costa Rica
44.163.48 Nicaragua
44.163.64 Honduras
44.163.80 El Salvador
44.163.96 Guatamala
44.163.112 Belize
44.164 Surinam PZ2AC Otto Morroy
44.165 Poland SP5WCA Andrzej K. Brandt
44.166 Korea unknown
44.167 India VU2LBW Lakshman ("Lucky") Bijanki
44.168 Taiwan BV5AF Bolon
44.169 Nigeria 5N0OBA Kunle
44.170 Croatia ?? Sinisa Novosel
44.171 Serbia (none)
44.172 Sri Lanka 4S7EF Ekendra
44.173 Mexico (pending)
44.174 Brazil PP5AQ Luiz F. Catalan
44.175 Cuba CO2JA Jose Amador
44.176 Turkey TA2LA Abdul-Hamid Sadka
44.177 Czech Republic OK2XTE Karel Odehnal
44.178 Russia RA3APW Karen Tadewosyan
44.179 Gibraltar ZB0D Jim Watt
44.180 Yugoslavia YT7MPB Miroslav Skoric
44.193 Outer Space-AMSAT W3IWI Dr Tom Clark
TCP/IP Software Sources
The various versions of TCP/IP software may be obtained from
the following sources:
IBM-PC/MS-DOS version of NET is available from:
Tucson Amateur Packet Radio (TAPR), 8987-309 East Tanque Verde Rd
No. 337, Tucson, AZ 85749,
(817) 383-0000 (voice mail), (817) 566-2544 (FAX)
Apple Macintosh version of NET is available from:
Doug Thom, N6OYU, c/o Thetherless Access Ltd, 1405 Graywood Dr,
San Jose, CA 95129-2210
Atari ST version of NET is available from:
Mike Curtis, WD6EHR, 7921 Wilkinson Av, N Hollywood, CA 91605-2210
Commodore Amiga version of NET is available from:
John Heaton, G1YYH, MCC Network Unit, Oxford Rd, Manchester M13
9PL, England.
There's typically a nominal fee charged to cover the cost of
disk(s) and postage, so send an SASE first to find out what is
required. Also, some versions of TCP/IP software may be
downloaded from CompuServe's HamNet library 9.