PACKET RADIO: Addressing Packet Traffic

Steve Wolf, W8IZ @ W8IZ


(This text from the W8IZ packet radio bulletin

board. It's formatted to fit a 80 character screen.)


Let's say you are going to sit down and write a
program to allow your computer to be a PBBS. One of the
tasks you face is to write a forwarding routing. You
have to insure that if one of your users leaves a message
for someone somewhere else, it will be properly forwarded.
That means anywhere in the state, country or world.
Anyone--how many people are on this planet? Pretty rough
task I would say!

AN OVERVIEW
When Mike, WA8BXN, wrote MSYS, he used the philosophy
that if ever forwarding board knew about all the other
forwarding board in its own state, much of the job would
be completed. The NCARC PBBS knows all about Ohio.
From there, a system called Hierarchical Routing is
used. If you give some additional information about the
destination of your message, the PBBS can figure out where
to send it. If it knows that your message is bound for
California, it can send it to a station in California
that knows all about California and will take the message
from there. If your message is for out of the country,
the PBBS can make a decision about where to send the
message to get it out of the country.
IT IS UP TO THE ORIGINATING STATION TO PROVIDE THIS
LITTLE BIT OF ADDITIONAL INFORMATION TO ALLOW YOUR MESSAGE
TO BE ROUTED!

A MESSAGE GOING TO ANOTHER AMATEUR IN OHIO
This is a simple task. You "SP callsign @
PBBScallsign". The PBBS knows about forwarding PBBSs in
Ohio and will make a decision about where to send the
message. It may go west to Sandusky, East to Kirtland,
South-East to Akron. It will be on its way.
But, if you do not know what PBBS you friend uses,
you can also send it via Zip Code. If nothing else,
someone will call your friend with the message and perhaps
the two of you will exchange information about PBBSs you
use.

A MESSAGE ROUTED TO ANOTHER AMATEUR IN ANOTHER STATE
You need to know one little bit of additional
information: The state that your friends PBBS is in.
You then issue a "S callsign @ PBBScallsign.State"
command. For example, to send a message to N8GNJ in
Seattle, Washington, at KD7NM PBBS, you would issue a
"S N8GNJ @ KD7NM.WA" command. The NCARC PBBS looks at
this command, realizes it can not route to KD7NM and then
looks for the ".WA". Seeing that, it gets the call
of the PBBS it knows can handle the traffic and routes
it there.
I DON'T KNOW THE STATE! This might happen if you are
replying to a message you read on the board. Don't cause
me work, OK? Do this: In the NCARC use the "P" command
to see if the board knows the callsign of the station
you want the message to go to. "P callsign" is all you
need. Now then, if it does know, it will tell you the
state that the receiving PBBS is in. Use that. If nothing
comes back then use the "PF" command on the PBBS that your
friend gets his mail on: "PF PBBScallsign". If nothing
comes back on that try, then look up the home state of the
PBBS in a recent Callbook. If you don't have one, leave
a message for SYSOP or NCARC requesting us to do it. You
can then send your traffic.

SENDING A MESSAGE TO A NON-AMATEUR
(OR AN AMATEUR WHOM IS NOT ON PACKET)
(OR AN AMATEUR YOU DO NOT KNOW THE PBBS OF)
This type of traffic is routed with the command:
"ST zipcode @ NTSxx". You supply the state abbreviation
(xx) and the zipcode. The PBBS will look up the proper
routing for the state and send it there. Once in the
state, a PBBS will look up the zipcode and determine the
best board to send it to. To send a message to
Brooksville, Florida, I would use "ST 34601 @ NTSFL".
Always, on this type of traffic, include a phone
number. If it can be delivered close enough, someone
can call. If not and it gets lost, it is likely to get
bounced back to you.

ALWAYS, ALWAYS, ALWAYS
Always use the message title to hold more information
on the traffic. Use the city and state of the recipient
to help the routing. Even if you constantly send traffic
back and forth, use it. "S N8GNJ @ KD7NM.WA" with a
title of "Seattle, Washington" is fine. N8GNJ lives in
a suburb outside of Seattle, but getting it that far
insures it's delivery. "ST 34601 @ NTSFL" followed by
"Brooksville, Florida" insures its routing.

ABOUT ZIP CODE ROUTING
There are those who feel that zip code routing is
not the proper way to send traffic. In many areas, the
zip code will not properly force the traffic to the
destination. However, at this time, it should get it
close enough to get delivered. If you intend to use
the route often, try a message to "SYSOP" at your
intended destination. The sysop should reply with
information about the proper routing that you could use
in the future. You would then use a "ST zipcode @
PBBScallsign".

TRAFFIC GOING OUT OF THE COUNTRY
Send a message to NCARC or SYSOP for assistance. Many
parts of the world are active but there is a whole lot of
world! Many times you might also investigate APLINK
as a route. BE CAREFUL, CHECK THIRD PARTY REGULATIONS
PRIOR TO EVEN TRYING!

DELIVERY TIMES
Delivery time depends on the route. An hour or two
is not uncommon for transcontinental traffic.

FORMAL TRAFFIC
Formal traffic is covered in another file.


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