According to RFC 6184:
Annex B of H.264 defines an encapsulation process to transmit such NALUs over bytestream-oriented networks. In the scope of this memo, Annex B is not relevant.
I see a lot of examplex, including in RFC6236, of SPS/PPS like this
a=fmtp:99 packetization-mode=0;profile-level-id=42e011; \
sprop-parameter-sets=Z0LgC5ZUCg/I,aM4BrFSAa
However, according to H.264, Annex B, there should be no comma, and a preamble must be added to the beginning of both SPS and PPS (and after that SPS/PPS is converted to base 64).
So I don't understand what is the right thing to do.