lorawan doesnt support setting the FPort

[jhelberg]

A default FPort of 1 is used now.

The use of FPort (similar to port aka service in TCP) is quite widespread and can, formally, reduce the payload with 1 single byte.
The lorawan implementation should not hide the FPort from the API.

I'm happy to submit a pull-request where the Session struct has a extra field: FPort and the code where fport is set to 1 now consults the presence of a legal FPort in the Session struct first.

[ofauchon]

Hi @jhelberg,

You are right, fport should be implemented, as it can be useful for multiplexing uplink messages transmissions on the same lorawan session.

How do you plan to change the new fport value in the session struct ?
With some SetFPort() function ?

Could you please share the code handling FPort ?

I'm still wondering if fport should be part of the session or lorawan message generation :

-func (s *Session) GenMessage(dir uint8, payload []uint8) ([]uint8, error) {
+func (s *Session) GenMessage(dir, fport uint8, payload []uint8) ([]uint8, error) {

Olivier