PACKET RADIO: Streams
(This text from the W8IZ packet radio bulletin
board. It's formatted to fit a 80 character screen.)
MULTIPLE SEPARATE CONVERSATIONS
We are talking about STREAMs and USERS here. Normally
USERS is set to one. That means that only one connection
can be achieved at a time. If anyone tries to connect to
you, they will get a "busy" message and be disconnected.
The STREAM commands are disabled when USERS is one.
Let's make USERS a different value, let's make it
ten. Let's also set up the TNC so it is easier to use
for multiple connections. Set STREAMDBL to ON. Now, you
have to determine which key represents the hexidecimal 7F
character that will tell your TNC to switch conversations.
You might have to experiment until the character on the
screen matches the one in your TNC manual.
Now connect to two stations at the same time.
On the receive side, you will see what both stations
are sending you. To switch conversations on the transmit
side, you use the stream-switch character.
On the HF side, where the data transfer rate is
rather slow, keeping track of two, three or even four
conversations is possible. On VHF, with rapid fire
comments, even two conversations can be a challenge.
MULTIPLE CONVERSATIONS WHERE
EVERYONE HEARS EVERYONE
We are quite lucky to have a conference on our PBBS.
This allows us to all join in a single conversations.
The first station in must begin the conference. This
is done with the "C" command. That station will then use
the control-Z character to preface all further commands.
A control-Z character is obtained by pushing and holding
the control key (the clear key on some computers) and then
pushing the Z. Control-Z followed by H will give you the
help for the conference commands. (Push and hold the
control key. Push the Z key. Release both. Type a
regular H. Type an ENTER.)
If it was not predetermined to meet in the conference,
you will have to ask the others to join you. To do this
you need to know what computer channel the others are on.
A control-Z U will give you this information. Another
control-Z command is then used to invite them over to the
conference. Your friend just types a C command to join.
The system is very particular about one thing. Don't
send line lengths longer than 80 characters. You will find
that it ignores what you send after 80 but keeps track of
how many characters you send. When it is retransmitting
it to the other boards, it will send the number of
characters you sent it. It will just send whatever
garbage follows the 80th character. If it is a control-Z
followed by a B, it will disconnect you.
Numerous conferences can be in progress at the same
time. There is also the possibility of using the
conference in an emergency net.
Overhead is quite high. Each packet received from a
participant must be acknowledged by the board. It is then
sent and an acknowledgement comes back from each station.
On 145.09, due to the lack of forwarding and other PBBSs,
we can afford to utilize the conference as much as we like.
In fact, if using a node or digipeater between two stations
is needed, it may be more fun to use the conference
instead. Never know who might join you!
If you see calls like WA8BXN, KB8CI, W8GRG using the
board, don't be surprised if they ignore your invite to
join these conferences. They are PBBSs that forward mail
into our system!
PACKET CLUSTERS
Clusters exist in Cleveland, Columbus and other areas
of the state. These clusters are used for DX spotting and
are sometimes referred to as DX Spotting Nets. That is
their sole purpose, DXing. If you aren't interested in
DXing, you are playing in the wrong playground. If you
like DXing, participation will make your country total
quickly rise.
Like the conference on the NCARC PBBS, everyone is
connected together. If someone spots a rare DX station,
they enter it into the cluster. An alert is sent out to
all connected stations. There are also QSL services,
past histories of prefixes, bearing/distance information
and other services available.
You don't have to connect to the Cluster to see how
it works. Just monitor 144.95 for a bit. Before long
you may want to check in and participate.
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