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BPQAXIP

Introduction:

BPQAXIP supports the encapsulation of AX.25 frames in IP, as defined in RFC1226. It also supports encapuslation in UDP, as used by some UNIX systems, and TCP.

Environment.

The program uses Winsock Version 2. This is provided as standard in NT 4 / Windows 98 and later systems, but must be installed on Win 95 before the program can be used. You will need to download it from Microsoft(ws2setup.exe).

UDP Source Port.

Some implementions of AX/IP require a specific UDP source port. Prior to November 2010, BPQ32 would use the first port defined in a UDP line as the source port. Now, by default the software will try to use the same port for both source and destination, unless overridden by the SOURCEPORT parameter. In both cases, the source port that you are trying to use must be defined in a UDP statement. If is isn't, the software will revert to the old behaviour of using the port specified in the first UDP entry.

Configuration.

The driver is defined to BPQ32 as an External port, and needs some driver-specific configuration

Configuration Statements

UDP
Optional. Enables UDP support, and defines the port AX.IP listens on. You can have more than one UDP line if you need to listen on more than one port. To listen for IPV6, add ,IPv6 after port - eg UDP 10093,IPv6

MHEARD
Optional - opens a window to display a "Heard List"

BROADCAST
Defines a call that should be sent to all stations with a "B" specified on the MAP statement. You can have more than one BROADCAST statement.

MAP
Defines a relationship between a Callsign and an IP Address. There is a limit of 128 entries in the mapping table.

You can use raw IP encapsulation, using IP Protocol 93, or UDP or TCP, or a combination

Format is:   ([..] indicates optional paramters, values separated by | are alternatives)

MAP Call Address [UDP|TCP-Master|TCPSlave Port] [KEEPALIVE nnn][SOURCEPORT nnn] [B]

If Call has an ssid, the entry only applies to that ssid value. If no ssid is supplied, the entry applies to all ssid values. So, if you want to select traffic for only G8BPQ, you must specify G8BPQ-0.

Address can be a host name, or numeric IP address. For TCP-Slave it should be 0.0.0.0. The software will work with an IP broadcast address, but if the destination is on the same subnet you will receive your own broadcast frames.

UDP means use UDP Encapsulation, sending to Port.

TCP-Master and TCP-Slave are used in pairs, one at each end of the connection. These may be used in cases where it is impossible to set up your Internet Router to send UDP frames to your computer.

Keepalive. Many Internet Service Providers now use Address Translation, so they can allocate private IP addresses to their customers. Some routers will time out translation entries that are idle for more that a short time. BPQAXIP can be configured to send a dummy "Keep Alive" message every nnn seconds if this is a problem.

SOURCEPORT. Some AX/IP implementations require UDP datagrams to be sent from a particular port. The software will use the destination port as the source port, unless overridden by this parameter.

The B parameter causes packets matching the BROADCAST definitions to be sent to this station. Normally you would have BROADCAST NODES and a B on each MAP entry, so that all stations see your NODES broadcasts. An exception is when using INP3, when the B would normally be omitted.
Some Examples:

MAP G8BPQ-7 10.2.77.1 B           # Use Raw IP encapulation
MAP G8BPQ g8bpq.no-ip.com B       # Sends all ssid's of G8BPQ	

MAP G8BPQ-7 10.2.77.1 UDP 10093 B  # Use UDP encapulation, send to port 10093

MAP G8BPQ-1 example.net TCP-Master 10093 B # Connect using TCP to host example.net, port 10093

MAP G8BPQ-5 0.0.0.0 TCP-Slave 10093 B      # Listen for TCP connections on port 10093

AUTOADDMAP
This option automatically adds the node call and address of a node from which you receive a UDP packet for which you do not have a MAP entry in bpq32.cfg.

DONTCHECKSOURCECALL
This option allows packets to be received from stations for which you don't have a MAP entry. This should only be used in exceptional circumstances, as normally you will want to b able to reply to received packets.

if option DONTCHECKSOURCECALL is specified then the AUTOADDMAP option is ignored.

Sample Config file for BPQAXIP


PORT
 ID=AXIP Link
 DRIVER=BPQAXIP
 QUALITY=200
 MAXFRAME=4
 FRACK=7000
 RESPTIME=1000
 RETRIES=10
 PACLEN=120
 CONFIG
 
 UDP 10093                 # Optional. Enables UDP support, and defines the port
                           # AX.IP listens on. You can specify more than one
                           # UDP line if you need to listen on more than one port
                                 
 MHEARD                    # Optional - opens a window to display a "Heard List" 

 BROADCAST NODES
 BROADCAST APRS

 MAP G8BPQ-7 10.2.77.1 UDP 10093 B
 
ENDPORT

John Wiseman G8BPQ
October 2010