[Xastir-dev] strange chars in APRS packets, xastir failed to decode path !

[Tapio Sokura]

Thomas Hoffmann wrote:
> Investigation revealed that there are  some strange "<UI>" characters in the 
> digi path which prevented xastir from decoding the digi path. A log of my TNC 
> traffic is shown below. 
> 
> ---------------------------------------------------------------
>  0:TNC-> IK3XTM-12>APRS,IQ3VO,WIDE7* <UI>:!4529.59N/01057.58Ej035/005 
> Op.Gianluca ARI/R.E. Member

You can get around the header differences between TNCs by using KISS 
mode. Too bad the majority of users are still using command mode, even 
though almost all TNCs have had KISS for something like 15 years. 
Especially in UI communications like APRS there should not be that many 
good reasons for users to keep their TNCs in command mode instead of KISS.

If one wanted to make the tne header parsing more robust when using TNCs 
in command mode, I'd suggest ignoring everything between the last valid 
digipeater entry and the first ':' char. Hmmh, maybe this doesn't work 
too well either, as Kantronics TNCs can be made to output timestamps for 
each received packet and if I remember correctly, the timestamp is 
inserted between the digipath and the packet contents. And a timestamp 
often has ':' chars in it.. Oh well, better just use KISS.

   Tapio