[aprssig] Lowercase callsigns in AX.25/APRS messages

Andre aprs at pe1rdw.demon.nl
Fri Feb 17 15:24:59 CST 2012

Op 17-2-2012 21:58, Andrew P. schreef:
> In debugging my APRS client, I have noticed a few (very few) stations using lower case in their callsigns. Is this legal? It's obviously possible, since they are out there.
> Since they exist, should my application:
> 1. Match on their callsign using case-insensitive matching or case-sensitive?
> 2. Force users of my application to enter their own callsigns in uppercase?
> 3. Forcibly upshift their callsigns in the headers of forwarded/digipeated messages and/or displayed status tables?
> Example received from APRS-IS (I replaced my gateway's callsign with XXXXXX):
> }kc2yu-sn>APKRAM,TCPIP,XXXXXX*:/171917z4041.78N/07359.46W$sn
> Just curious how to handle these.
> Andrew Pavlin, KA2DDO
> Sent from my Verizon Wireless BlackBerry
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if you recieve a lowercase call trough rf ax25 it should be discarded as 
lowercase calls are against the AX25 specs, on APRS-IS all printable 
characters are legal but a lot of software will force callsigns to be 
entered in uppercase to keep the onair and APRS-IS callsign the same.
Technicale callsigns should be case sensative if both upper and 
lowercase is alowed on the IS and probably would be safer as the 
software alowing lowercase callsigns can be case sensative.
Altering their callsigns would be a big nono, only the servers are 
alowed to do that, igates must pass everything recieved unaltered and 
transmit only by insterting the } in front of the string to make it an 
thirthparty frame.

73 Andre PE1RDW

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