Josephine County ARES Packet Info

The Packet Network

In the Southern Oregon/Northern California region covered by SOAPRA, two separate networks are in operation. They are as follows:

  1. A general data network for BBS access, BBSforwarding, DX Cluster and data transfer.
  2. A keyboard network for direct station to station communications.

Some general conventions for using the network:

  1. In the SOAPRA system the convention is to use the -4 SSID for your PBBS or Personal Mailbox in your TNC. For example, mine is on N7ZWU-4. This allows anyone to know where to find your mailbox in this area. To allow the mailbox to function, just leave the radio and TNC on and anyone can leave you a message!
  2. When participating in Station-to-Station traffic, also referred to as keyboarding end your message with ..k to inform the person on the other end that it is now their turn to send.

Frequencies - Nodes

{General} {County} {Full Service BBS} {WX Spotting} {DX Cluster}

General Frequency Use

145.01 is a general use non-protected frequency for experimentation, personal traffic, etc. Any nodes on this frequency are not coordinated by the regional frequency coordinators and are probably there for test purposes.

144.39 is the National APRS frequency. We don't have any APRS digipeaters set up at this time, have been using digipeating through local keyboard network nodes when we have been experimenting with it.

144.910 through 145.090 on 10kc channels is assigned to packet under the Oregon Regional Relay Council (ORRC) bandplan. It is best to use local frequencies 20kc in separation to avoid cross channel interference

County Packet Frequencies

Douglas Co Packet Network Access
Call Alias Frequency Network
AB7DC DC 145.09 Local Access Node

Josephine Co Packet Network Access
Call Alias Frequency Network
KD7BMK-1 GPASS 145.01 Local Access Node
N7ZWU-1 JOSBBS 145.01 Full Service BBS
N7ZWU-8 JOSNOD 145.01 Local Access Node
N7ZWU-10 JOSCHT 145.01 Round Table Node - CHAT
WB7BPI-1 KING 145.07 Local Access Node
WB6YQP-2 JOCO 144.93 Keyboard

Josephine Co ARES Stations
Call Tactical Function
KC7WIS EOC Keyboard
KC7WIS-4
PBBS
KC7WIS-8
KA-Node
W1LMA TRCH Keyboard
W1LMA-4
PBBS
W1LMA-8
KA-Node
KD7QCT CJECC Keyboard
KD7QCT-4
PBBS
KD7QCT-8
KA-Node
N7HGP TRLR Keyboard

Jackson Co Packet Network Access
Call Alias Frequency Network
WB7AWL AWLBBS 144.98 Full Service BBS
WB7AWL-8 TALENT 144.98 World Access Node - CHAT
WB7AWL-15 OREGON ? TNOS BBS
WX7MFR NWSMFR 145.09 Skywarn BBS
KB7SKB-1 SODA 144.98 Local Access Node
WB7BPI-1 KING 145.07 Local Access Node
KA0DFN-1 MFR 144.93 Keyboard

Klamath Co Packet Network Access
Call Alias Frequency Network
KK7VO
145.77 Winlink BBS
K7DDI-6 KFALLS 145.77 Local Access Node
K7DXV-2 KLMT 144.93 Keyboard
K7DDI-2 KENO 145.05 Keyboard

California Packet Network Access
Call Alias Frequency Network
KE6YJH-1 SCARA 145.01 Local Access Node
KJ6RA-3 YREKA
Keyboard
K6JKC-5 MODOC
Keyboard

Full Service Bulletin Boards

Call Alias Service Area
N7ZWU-1 JOSBBS Josephine Co.
WB7AWL AWLBBS Klamath Co., Siskyou Co., Del Norte Co.
KK7VO
Klamath Co.

Weather Spotting

Call Alias Service Area
WX7MFR NWSBBS NOAA Weather Station MFR
Southern Oregon - Northern California

DX Cluster

Call Alias Service Area
MFRDXC K7VS Access from any SOAPRA Node
Southern Oregon - Northern California

What is Packet

The Basic Station

A basic packet radio station consists of a Computer, Terminal Node Controller (TNC) and a Radio.

  1. The computer serves as the input and display device so you can send and receive typed messages or transmit and receive stored data.
  2. The TNC is a peripheral device with two main functions:

    Transmit: The TNC takes in serial data and assembles it into a data frame (packet) consisting of addressing, control information, the actual message you are sending and Checksum (error detection information). It then keys the radio and sends the packet using two-tone audio or FSK modulation.

    Receive: The TNC takes in received audio, demodulates it, retrieves the data frame (packet), disassembles it to see if it's addressed to you, reads control information, checks to see if there were errors and then sends the message out the serial port to your computer for display or storage.

  3. The radio serves to get the packet on the air. It receives and transmits the packets via either AFSK (1200 baud) or FSK (9600 baud).

Noise On The Air

Packet operation is similar to simplex voice radio operation. Listen before you key up on the frequency! If you are transmitting, you can't hear! If someone keys over the top of you, you get a double and nothing intelligible gets out!

To handle multiple people operating on packet, the TNC uses a method called Carrier Detection (CD). It listens to the frequency to make sure it is clear before transmitting. If two stations do transmit at the same time, this is called a collision. The receiving stations cannot detect any data when this happens. The transmitting stations at this point get no acknowledgement and try to retransmit. TNC's have a function called PERSIST/SLOTTIME that helps them to not do this retransmit exactly at the same time again.

Just like voice operations, repeaters are used to extend the range. You can even use a linked repeater system to extend the range further. Unlike most voice repeaters, though; packet repeaters operate in simplex mode. This means that they have to receive the packet, store it and then retransmit it. Packet repeaters have two different names, depending on the type of operation. They are called either digipeaters or nodes.

Who Am I Addressing

For your station to effectively get on the air, you have to give it an address. Just like getting postal mail or internet e-mail, there must be a starting destination and an ending destination, otherwise you are merely heating the air with RF energy. The simple method used in Amateur Packet Radio is to assign your call sign as the address.

Now this is pretty good if you just want to communicate between two individual stations, but what if you want to also have a mailbox and a node on the same frequency at one of those stations, for example KC7WIS? Stations attempting to connect would have a hard time determining which device was really KC7WIS now, and KC7WIS would have a hard time determining which personality to display! To get around this problem, a number referred to as an SSID is appended to the address call sign for the subsequent identities.

There are 16 SSID's available. In our earlier example this would give us KC7WIS-0 through KC7WIS-15. The -0 SSID is equivalent to the address call sign. Using the SSID now, we can assign the station call as KC7WIS, the mailbox (PBBS) as KC7WIS-4 and that KA-Node as KC7WIS-8. Now this TNC can take on several functions at once, serving as a keyboard device, mailbox and node all under one call sign.

Let's Get Connected

Packet Radio can operate in an unconnected mode sending out what are called UI frames or Unproto Packets. To do this, choose a clear frequency, turn your TNC monitoring on, put your TNC in convere mode, type in a message and send it. The other station can do just the same, and you can keyboard back and forth. This is the simplest method of communications with packet.

There are advantages to using the unconnected mode. In weak signal work, you can turn a function called passall on and it will display all received packets whether they pass the error correction or not. This of course puts the interpretation as to what was received on your shoulders, but eliminates failure to receive a packet because it was partially corrupted. Also in modes such as APRS, hit or miss methods work quite well since the data will be repeated at intervals.

The main disadvantage comes about when you try to share a frequency between more than two stations. You now find out that Monitor displays all packets transmitted on the frequency. If you are running a roundtable chat, that is fine as you pass the speaker's staff to the next person in sequence, but what if you have four stations that want to hold two individual conversations?

Connect!

In technical terms connection or linking is the action of forming a virtual ciruit using the network resources available. Doggonit, speak English! Ok, connecting is one TNC informing another TNC that it wants to hold a private conversation without all those others butting in and spewing unwanted information all over your screen. Now, two or more pairs of stations can send data or messages independent of the other pairs.

The basic connect takes place from station to station. What happens now if you are trying to connect to a station that is just out of range? You ask an intermediate station to repeat your message to the end station.

Two different types of stations are used for repeating Packet transmissions:

Digipeating: This is the simplest form of repeating. All TNC's can act as digipeaters. You can connect to the end station via a chain of up to eight intermediate stations. It has the advantage of being slightly faster in transmitting the messages along the chain on a clear frequency; however, only the end stations check the packet for errors. If an intermediate station in the chain receives a corrupted packet, it just passes it on to the end station which then has to send a request for retransmission all the way back to the originating station. A digipeater circuit can degrade and fail very quickly with excessive traffic or interference.

Node Network: Nodes are a special form of packet station. Some TNC's have one built in, most Nodes are TNC's with special software for dedication to this use. You can connect to the end station through about sixteen Nodes. As a packet travels through a network, each Node checks the packet for errors and asks the previous station to resend it upon detecting errors. This allows for more efficient operation as the system discards garbaged packets immediately instead of passing them all along the network to the end station to be tested for corruption.

Another advantage to Node networks is that they are designed to learn about each other's ability to connect. This means that you can connect to a local Node, check its node list to see if a node exists near the end station, connect to that node and then connect to the end station. No knowledge is needed about all the intermediate stations call signs, frequencies, etc. The connect command propagates through the network until it establishes the connection with the desired station.

Since we are using Kantronics TNC's, we need to also discuss KA-Nodes. Most Kantronics TNC's have KA-Node capability. The KA-Node is a special limited node that allows you the advantages of a node's station-to-station error correction while not littering the air with all the node routing traffic or inserting itself into the network's routing tables which can cause real havoc when you shut it off after a packet operating session. To use a KA-Node, you must know it exists. To use a basic network of KA-Nodes, you must know the call signs and individually connect to each one.

Summary

Packet Radio allows you to take computer input, assemble it into addressed packets with error detection and transmit these packets over the air to another station. For more distant transmissions, the packets can be digipeated or sent through a node network.


Basic Kantronics TNC Commands

TNC Modes

Before you get started, you must understand that a TNC has two separate operating modes:

Command Mode: This is signified by the cmd: prompt. All TNC commands for setup, connection, disconnection, etc. are entered here. You can reach command mode at any time by holding down your Control key and then typing C (CTRL-C).

Converse Mode: Most TNC's are set up to immediately put you in this mode upon connection to another station. In Converse mode, anything typed and then followed by an enter is transmitted over the air. You can get to Converse mode from the cmd: prompt by typing K and then enter.

Help!!

Your Kantronics TNC has a very nice feature. Type HELP at the cmd: prompt, press enter and it lists all the TNC commands available. Type HELP followed by the command, then press enter and it tells you what that command does, usually with a short example of the command and parameters that need to be entered.

Basic Setups

DISPLAY
Shows a list of all the settings currently used by the TNC.
TXDELAY N
N is a number from 0 to 255. Sets transmitter key-up delay to 10*n milliseconds. This sets the delay between PTT and start of packet audio being sent to the transmitter. Default setting is 30 for a delay of 300 milliseconds. Depending on transmitter latency, this can be shortened or lengthened. Take into consideration relay closing time (if so equipped), transmitter power and frequency stabilization. Too short a time chops packets, too long just wastes time.

The following commands set the address call sign the packet station operates under. Check these when the station operator changes:

MYCALL CALLSIGN
This sets the station to use your call sign and if you don't have another packet station on frequency, enter just your callsign with no SSID.
MYPBBS CALLSIGN-4
This sets the Mailbox (PBBS) call sign, use the -4 SSID so all people on frequency know where your mailbox is if you are on the air.
MYNODE CALLSIGN-8
This sets the KA-Node call sign, use the -8 SSID so all people on frequency know where to connect if they need to use your station's KA-Node.

Operational Commands

The Least you need to know to get started:

C CALLSIGN {VIA CALLSIGN1, CALLSIGN2}
Connect to another station. Use the callsign of the other station, or in the case of a node, you may use its ALIAS. You might have to add an SSID to the callsign. Also if you need to digipeat, enter the VIA callsigns in the order of nearest to furthest station. There can be up to eight stations in the digipeater chain. If the other station is not on the air, or you flubbed the callsign, your station will try to connect until it exceeds the maximum retries.
CTRL-C
Hold down your Control key and then press C while connected. This changes you from Converse Mode to Command Mode. Useful for entering commands such as DISCONNECT, etc.
DISCONNECT
Severs the connection to the other station. Only one station in the connection needs to do this. If you don't sever the connection and just shut the TNC off, the other station and any other stations involved in the link will have resources tied up until the link active timeout expires.
K
Go back to Converse mode after entering a command at the cmd: prompt.
MHEARD {SHORT | LONG | CLEAR}
MHEARD by itself shows you a list of stations heard with date/time last heard. If you see an asterisk, *, the station was heard through a digipeater. MHEARD SHORT displays only callsigns, MHEARD LONG shows all callsigns in the received packet including the digipeater chain. MHEARD CLEAR clears out the MHEARD list.

Monitoring Functions

The following commands set monitoring functions so you can observe frequency activity:

MONITOR ON or MONITOR OFF
While you are not connected to anything, MONITOR ON turns on monitoring of packet frequency traffic. You can use this to figure out who is on the air, or just observe how data packets pass through. The following commands modify what you see when in monitor mode.
MALL ON or MALL OFF
When this is turned on, you monitor all connected and unconnected packets.
MBEACON ON or MBEACON OFF
When this is turned on, beacon packets will be displayed.
MCOM ON or MCOM OFF
When this is turned on in addition to having MONITOR turned on, you can monitor all the control packets as well, for observation of connect and disconnect requests, sequence numbers of information packets. This can be used as the first level of diagnosis for any network problems
MRESP ON or MRESP OFF
When this is turned on in addition to having MONITOR and MCOM turned on, you can monitor all response packets. These are things like Frame Reject, Reject, Receive Not Ready, Receive Ready and Information Frame Send/Receive sequencing. This is the second diagnostic level for tracking down such problems as execssive retries, failures to connect, etc.
MRPT ON or MRPT OFF
When set to on, displays all stations in the digipeat chain with an asterisk, *, beside the station that relayed the packet. Useful for watching packets travel down the chain to see where problems occur while digipeating.
MCON ON or MCON OFF
Monitor everything even while you are connected. A highly annoying mode if you get here accidentally, but highly useful as the third diagnostic level available for troubleshooting. If your station is monitoring everything even after you have connected, shut this off!!
PASSALL ON or PASSALL OFF
When this is on, TNC will attempt to decode the packet despite the fact that the Checksum shows the packet to be corrupted. Can be used for diagnosis, or in extreme cases where you are attempting to get a message through very poor transmission paths.

Basic PBBS Commands

x


Basic Node Commands

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Basic Full Service BBS Commands

The really long winded version that gives you all you wanted to know for W0RLI and F6FBB