1. SIP Resource Priority Henning Schulzrinne/Columbia University
James Polk/Cisco
15 November 2018
53rd IETF -- SIPPING

2. Resource-Priority Header
Goal:
establish preferential (or deferential...) treatment for sessions when competing for destination UA resources
typically telephony gateways (not necessarily PSTN)
usually MLP, but could be gateway resources only
cf. SIP Priority header: influence treatment by human user
15 November 2018
53rd IETF -- SIPPING

3. Changes since last time
Namespace.priority
e.g., dsn.flash,q735.0
IANA registration procedure
Clearer definition of default behavior
overall goal: maximize call completion
Resource-Priority expected, but none
policy issue, recommend treat at default level
recipient doesn’t understand name space
policy issue, recommend ignore and treat as if no Resource-Priority header
recipient doesn’t understand priority level
15 November 2018
53rd IETF -- SIPPING

4. Error behavior 503 (Service Unavailable) if insufficient priority
Warning: 370 (Insufficient Bandwidth)
Open issue: separate codes?
15 November 2018
53rd IETF -- SIPPING

5. Open issues All comments integrated – new I-D after IETF53
Minor issue: Accept-Resource-Priority?
Otherwise considered done
Authors request hand-off to SIP (since new header) for PS track
15 November 2018
53rd IETF -- SIPPING