In particular, he noted that although the basic SIP idea has been around for a while no stable state has been reached yet and that in the past only little third party review took place. Recently, SIP started broadening its scope and keeps steadily growing which prevents it from becoming stable. This work will require to split away the part of SAP dealing with multicast address allocation. Mark noted that this does not require protocol changes, but updates to the descriptive text may be needed in various parts of the document. It is suggested to use the GZIP compression algorithm, but it was pointed out that GZIP is not sufficiently well specified at this point.
Further work is needed here.
A brief discussion on the use of the delete message for session announcements was held. It was found that the default means to delete session announcements should be a timeout with delete messages used as an optimization. However, for the base session announcement multicast address, SDP should be the default payload type. For authentication, a generic authentication header is provided which is followed by an algorithm-specific subheader. For symmetric encryption, the approach of the basic SAP specification is followed, hybrid encryption schemes make use of a combination of a generic header and an algorithm-specific subheader.