APRS-IS services are services provided by individuals via the Internet that can be
accessed from an APRS client anywhere in the world. Some services, like the NWS
weather server, automatically generate APRS messages that are valuable to
emergency operations on RF. Others provide capabilities like accessing the
Internet email network.
?APRST and ?PING? Directed Query Support
Have you ever wondered how you were being seen on APRS-IS or if your signal
was making it to APRS-IS? Send a directed query to CQSRVR, EMAIL, EMAIL-2, or WHO-IS to see your path
as seen by those servers. In other words, if I send a message to CQSRVR from my handheld (AE5PL-7)
with the content of ?APRST, I should expect a message response from CQSRVR that will contain the path
that CQSRVR saw (see below). Note that you will see the path exactly as CQSRVR sees it which will
include the q construct followed by the "port-of-entry".