port for unknown protocol

hi,
got a gps tracker but don't know what protocol it's using, what port number I should set so that I can analyze the feeds from that device? Thanks

https://www.traccar.org/identify-protocol/

thanks for the quick response, it's very helpful

ok, got a long hex string from port 5001, after converting hex to text, got something like this:
HQ,9175570011,V1...

what port should I use for this? Thanks

5013 seems working

a new device, got following in port 5001:

2024-01-15 20:02:49  INFO: [Ta13d38a5] connected
2024-01-15 20:02:49  INFO: [Ta13d38a5: gps103 <  ip_goes_here] 78780d010357857045556067001656480d0a
2024-01-15 20:02:49  INFO: [Ta13d38a5] error - begin 21, end 24, length 18 - StringIndexOutOfBoundsException (... < Gps103ProtocolDecoder:413 < ExtendedObjectDecoder:75 < ... < WrapperContext:102 < ...)
2024-01-15 20:02:49  INFO: [Ta13d38a5] disconnected

can not find useful information here, any idea ?

from this string : 78780d010357857045556067001656480d0a

i know 357857045556067 is the IMEI number, any idea which port supports this? thanks.

test with 5023

5023 works! it shows gt06, thanks