1 draft-lefaucheur-emergency-rsvp-00.txt RSVP Extensions for Emergency Services Francois Le Faucheur - Francois Le Faucheur, James Polk, Cisco Systems Ken Carlberg G11

222 Background RFC3689 & RFC3690 define the requirements for support of Emergency telecommunications services, including: Elevated probability of session establishment from an authorized user in times of network congestion (e.g. crisis condition) “mlpp-that-works” defines how network-based CAC (e.g. RSVP) can be used to achieve: MLPP Services (e.g. DoD/NATO’s MLPP) All necessary RSVP extension already standardised CAC may also be used for Emergency (Jury is still out) Small RSVP extensions needed : Objective of this document RFC 3689 “General Requirements for Emergency Telecommunication Service (ETS)” RFC 3690 “IP Telephony Requirements for Emergency Telecommunication Service (ETS)” draft-ietf-tsvwg-mlpp-that-works-04, “Implementing an Emergency Telecommunications Service for Real Time Services in the Internet Protocol Suite"

333 Changes from Previous version added a second RSVP Policy Element –contains the application-level resource priority requirements (for example as communicated in the SIP Resource-Priority Header) –for scenarios where priority calls transits through multiple administrative domains added description of a third (simpler) bandwidth allocation model example: the Priority Bypass Model added discussion on policies for mapping the various bandwidth allocation model over the engineered capacity limits

444 Proposed Extension: New Policy Elements (inside Policy Data object) | Length | P-Type = ADMISSION_PRI | | Flags | M. Strategy | Error Code | Reserved | | Rvd | Pri| Reserved | Reduced to 3 bits | Length | P-Type = APP_RESOURCE_PRI | | Flags | M. Strategy | Error Code | Reserved | | ARP Namespace | ARP Priority| Reserved | Application-Level Resource Priority Policy Element Admission Priority Policy Element e.g. "dsn", "drsn", "q735", "ets" and "wps"

555 R3 P1 Use of Application-Level Resource Priority Policy Element in Multi-Domain yy ets.0 xx yy SIP Message SIP Resource-Priority Header RSVP Message RSVP “Application-Level Resource Priority” Policy Element RSVP “Admission Priority” Policy Element ets Give ets.0 highest Admission Priority ets.0 2 Give ets.0 Medium Admission Priority Domain 1 Domain 2

666 Admission Priority Operations Example: Priority Bypass Model Admission Control Limit (for non-priority sessions) Non-priority call Priority call New non-priority call REJECTED New priority call ACCEPTED Total Link Bw

777 Engineering Trade-Off Example: Engineered Capacity for Voice Admission Control Limit (for non-priority sessions) Non-priority call Priority call Total Link Bw Option 1: Admission Control Limit set BELOW Engineered Capacity: * Some capacity set aside for Emergency (  accept less non-priority calls in normal time) * QoS absolutely guaranteed (Emergency sessions fit within Engineered Capacity)

888 Engineering Trade-Off Example: Engineered Capacity for Voice Admission Control Limit (for non-priority sessions) Non-priority call Priority call Total Link Bw Option 2: Admission Control Limit set EQUAL TO Engineered Capacity: * No capacity blocked for Emergency (ie no waste) * Emergency sessions eat into QoS safety marging

999 Open Issues (1) Support ETS emergency type sessions which need: - to benefit from elevated admission priority - to be able to preempt other ETS emergency type sessions - to not be able to preempt non-emergency sessions. One approach: Add a new Flag in the “Preemption Priority” Policy Element: – which reduces the scope of RSVP preemption to emergency sessions.

10 Open Issues (2) In case of Multicast Sessions, Merging Rules for “Application-Level Resource Priority” Policy Element: One approach is reunion of all the namespaces

11 Next Steps Accept as Working Group document Address open items when issuing as WG doc