so ive been running APRS for about 6 months now, got a TM-D710G in the truck and its been working pretty well for tracking purposes. i can see my position updating on aprs.fi no problem, usually every 2-3 minutes depending on how fast im moving with the smart beaconing turned on. but the messaging part is driving me nuts.

sent a message to a buddy of mine who was running Xastir on his laptop at home through his igate setup and he never got it. i could see my message packet going out in the log but nothing on his end. he tried sending back to me and i got nothing either. we both show up on the network just fine, its just the two-way messaging that isnt working.

is there something specific i need to do for messaging to work vs just tracking? i assumed if im beaconing and getting digipeated that messages would work the same way but maybe thats not how it works. been googling for an hour and getting kinda mixed results on what the actual flow is for APRS messages

the tracking and messaging paths arent quite the same thing, thats probably your problem. when you beacon your position it just goes out and gets digipeated and picked up by an igate and thats kind of the end of it. but for messaging to actually reach someone, the message has to flow from rf through an igate, then across the APRS-IS network, then back down through another igate near your buddy and out over rf to him -- and that last hop is where it usually breaks. not every igate is configured to gate traffic back down to rf, a lot of them are receive only. so your buddy might be on an igate that just listens but doesnt transmit back out.

check if the igate near him is listed as a bidirectional gate on aprs.fi, you can click on the igate symbol and it should say. if its rx only thats your issue right there. also make sure his SSID is right when you address the message, that trips people up constantly.

yeah what he said about bidirectional igates is exactly it, took me forever to figure that out too. also one thing that got me -- the D710 has a separate setting for whether its listening for ack packets or not, if your message sends but you never get an ack it just keeps retrying and eventually gives up. might look like it sent but the other station never saw it. Xastir should be sending an ack automatically if it got the message so if youre not seeing that come back then its definitely a path issue somewhere in the middle