# Configuring an APRS-IS Port

YAAC can communicate with the APRS-IS network on the Internet. To create an APRS-IS connection, click the Add button on the Ports tab of the Configure dialog, then change the Port Type to APRS-IS. The dialog will then appear like this:

The options to be set for an APRS-IS connection are:

- The Internet domain name of the APRS-IS gateway to be connected to. A list of all the world-wide Tier 2 gateway regional aliases are pre-provided for selection, but any other APRS-IS gateway's domain name may be typed in as well.
- The TCP port number at the gateway to connect to. The most common port numbers are provided, and 14580 should be selected unless a non-standard port is needed for some reason on a custom gateway.
- The passcode to use for logging into the APRS-IS network. If not provided, YAAC will not be permitted to I-Gate RF traffic into the Internet. If the field is left blank, it is assumed that this is to be a receive-only I-Gate connection.

  To obtain a passcode, contact YAAC's author by e-mail, and provide him with your government-issued amateur radio callsign. He will send back the passcode corresponding to your callsign.

- The filter expression for receiving traffic from APRS-IS. If a filter expression is not specified and this APRS-IS port is either not enabled for transmission or YAAC does not have a local RF port (Serial_TNC or AGWPE ports) declared and the standard filtered port (14580) is specified, a default radius filter of 80 kilometers around the fixed latitude and longitude defined for the beacon will be used. If the beacon latitude and longitude are not specified, a default radius filter of 50 kilometers around 39°15'N, 76°36'W (the location of the 2011 ARRL/TAPR DCC) will be used. If the APRS-IS connection is enabled for transmission and has a local RF port defined, no default filter will be applied; it is expected that the APRS-IS backbone servers will then only forward packets addressed to stations that have sent packets into the APRS-IS from here.
- Whether or not this port can transmit messages into APRS-IS; again, if an invalid passcode for the specified callsign is provided, the APRS-IS network will reject the connection attempt. For receive-only APRS-IS connections, a passcode is not necessary, and a default filter will be provided if an explicit one is not entered.
- Whether YAAC can connect directly to the selected APRS-IS server, or needs to relay the connection through a SOCKS server (only version 5 supported). If a SOCKS server is used, the host name of the SOCKS server (and colon-appended listening port if not the SOCKS default number 1088) must be specified, along with the username and password for logging into the SOCKS server.

The "Test Port" button provides a means of verifying that you have connected to the correct place; it opens a terminal window connected to the configured APRS-IS server so that you can manually test the server for the desired operation. To complete testing, close the terminal window.

Note that the Test Port button does not work for SOCKS-connected servers.

If both an APRS-IS port and an RF port are opened, YAAC expects to be used as an I-gate (Internet gateway) station. This tutorial explains more about I-gating.