Question: Why []Payload ? about lorawan

[brocaar]

As far as I understood from the specs it is possible to send multiple mac commands as one payload (as long as you don't exeed the max FRMPayload length):

A single data frame can contain any sequence of MAC commands, either piggybacked in the
FOpts field or, when sent as a separate data frame, in the FRMPayload field with the FPort
field being set to 0. Piggybacked MAC commands are always sent without encryption and
must not exceed 15 octets. MAC commands sent as FRMPayload are always encrypted
and must not exceed the maximum FRMPayload length.

When the lorawan package sees it contains mac commands (FPort = 0) it will combine these mac commands (and their payloads) as one DataPayload when encrypting, and it will break up the single DataPayload into separate payloads when decrypting.

So each FRMPayload will then be of type MACCommand, and based on it's CID, you're able to cast it's Payload (if it has one) into the right type (e.g. a LinkCheckAnsPayload type).

[KtorZ]

Ho. This is completely right, I forgot about that point on MAC commands. Thanks for reminding me!