APRS-SRV(9) XR32 REFERENCE MANUAL 4/2/2013
NAME
APRS-SRV -- APRS Server.
DESCRIPTION
XR32 includes a rudimentary APRS server, which enables
suitable APRS clients, such as UI-View, to connect to it on
the LAN and exchange APRS traffic. The number of simultaneous
clients is not limited.
TCP Port Number
~~~~~~~~~~~~~~~
The server listens for incoming connections on TCP port 1448.
There is a tradition of choosing port numbers for APRS servers
which represent the frequencies used by APRS, so port 1448 was
chosen because XR32 originates in the UK, and many European
countries use 144.800 MHz.
Overview Of Server
~~~~~~~~~~~~~~~~~~
The following APRS packets are sent to clients:
- APRS traffic received by any of XR32's radio ports.
- Traffic sent by other clients.
- Traffic sent by users of XR32's APRS messaging shell.
- Filtered traffic from Internet APRS servers (if XR32's
IGATE is connected to an Internet APRS server)
APRS packets from clients are distributed as follows:
- To other clients, excluding the sender.
- To XR32's APRS messaging shell.
- To radio ports (only if client is fully registered)
- To Internet APRS servers via IGATE (if IGATE is running).
Registration and Login
~~~~~~~~~~~~~~~~~~~~~~
Registration of clients is necessary to prevent unauthorised
use of radio frequencies by unlicensed people.
This may seem overly restrictive if your system is only used
on a private LAN, but if you are connected to the Internet,
it is essential. For example, if an unlicensed user connects
to your server via the Internet, he must be prevented from
sending traffic to your local RF ports. He must also be
prevented from sending traffic via your IGATE (if it is
enabled) into the Internet system, and thence to other
people's RF ports.
Therefore, clients are required to complete a log-in process
before they are allowed to send any traffic. Log-in is not
required for receive-only operations.
The server accepts two different types of login. When a user
registers an APRS client program such as UI-View, he receives
a "validation number" which XR32 uses in combination with the
callsign to verify the user. A verified user may send traffic
to local RF ports, or if IGATE is active, via other IGATES.
If the user has NOT registered his copy of UI-View, the
default validation number of "-1" allows him to send traffic
to other clients and to the Internet, but that traffic will
not be gated locally to RF, and is marked in such a way that
it will not be gated to RF by other IGATES. This allows
unregistered clients to communicate with each other via the
Internet, but not via RF. The client may only send APRS
packets whose source callsign matches the login callsign.
The alternative login system allows clients to verify
themselves by supplying their callsign and a password which
has been agreed with the sysop. The password replaces the
validation number in a login string.
The login string is the only "command" accepted by the server,
and must take the form: "user <callsign> pass <password>",
where <password> could be either a validation number or a text
string, for example, "user g8pzt pass beanzmeanzheinz", or
"user g7zzz pass 32751". Login is not acknowledged.
The Client Connection
~~~~~~~~~~~~~~~~~~~~~
There is no time-out on client connections, therefore there is
no need for the client to send "keep-alive" signals.
If the client connection is too slow to cope with the incoming
data rate, packets to the client may be discarded.
Local <> Internet Server Gating
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If IGATE is not running, no packets are gated to or from the
Internet.
Packets received from the Internet are not gated to clients
unless they satisfy the IFILTER (Internet Filter) filtering
rules in IGATE.CFG. Likewise, packets received from clients
are not gated to the Internet unless they satisfy the PFILTER
(Packet Filter) rules.
The following traffic is NOT gated from RF to Internet
- Packets in "third party" format.
- Packets which do not include the network identifier
"TCPIP" in the digi path.
- Packets which include the dummy callsigns NOGATE or
RFONLY in the digi path.
Using UI-View as a Client
~~~~~~~~~~~~~~~~~~~~~~~~~
Select Setup/APRS Server Setup.
In the box marked "Select A Server", enter the hostname and
TCP port number of XR32's APRS server, e.g. "myserver:1448" or
"192.168.0.2:1448". If the client is on the same computer as
XR32, use "localhost:1448" or "127.0.0.1:1448". (If you use a
private hostname, you may need to add a suitable entry into
the HOSTS file in the WINDOWS directory.)
Check the boxes marked "Open the gateway" and "Gate local
messages".
If you have a registered version of UI-View, check the box
marked "APRServe log on required", and enter your validation
number.
If your copy of UI-View is unregistered, you will be able to
log on to XR32's APRS server with the default validation
number of -1, but your packets will not be gated to RF.
To obtain full privileges using an unregistered copy, you must
have a password, which must be registered with your callsign
in XR32's USERPASS.SYS file. The callsign must not include
the SSID, e.g. if UI-View's callsign is "G8PZT-11", the entry
in USERPASS.SYS should simply be "G8PZT". Un-check the
"APRServe log on required" box, and in the box marked "Text
to send upon connection" enter UI-View's callsign (with SSID)
and your password in the following form:
user g8pzt-11 pass virago
SEE ALSO
APRS(9) -- APRS in XR32.
IGATE(9) -- APRS Igate.
IGATE.SYS(8) -- Igate Configuration File.
TCP-PORTS(9) -- TCP Service Ports.
USERPASS.SYS(8) -- User Passwords File.
XROUTER.CFG(8) -- Main Configuration File.
APRS-SRV(9) END OF DOCUMENT
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