Our Proposed Usage for Supporting NAs…
Issue: SIP is a session protocol, it transports in the context of a session that is established (e.g. INFO).
- Leverage IM work and use the method called MESSAGE, which behaves similarly to INVITE, but does not explicitly set up a session - it simply delivers its payload to the UA and carries back the response.
- Also need IM SUBSCRIBE and NOTIFY methods
Issue: How to address devices.
- Encode a hierarchical device naming scheme (e.g., SLP URL) to left of “@” sign in To: field.
- Encrypt encoded address to ensure privacy.
- Example: slp:/d=lamp,r=bedroom,u=stsang
Issue: SIP traditionally carries SDP payload.
- Need to define new payloads (==new MIME types) which can carry the information required to excite NAs and which can carry responses back to the originator.
- Propose a Device Messaging Protocol (DMP) MIME type