How is detail plan of stun implement ?

[tinymahua]

I found iroh's derp stun implement is base on stun-rs, and I also red the stun message code implement.
But iroh's stun message attributes only implement suport Fingerprint, although stun-rs defined some other attributes， eg：
(AlternateServer, stun), (ErrorCode, stun), (Fingerprint, stun), (MappedAddress, stun), (MessageIntegrity, stun), (MessageIntegritySha256, stun), (Nonce, stun), (PasswordAlgorithm, stun),

what detail plan about the derp stun mod?Thanks！