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Future Emergency Telecommunication Scenarios over the Internet. Dr. Ken Carlberg k.carlberg@cs.ucl.ac.uk. Emergency Telecommunications Workshop 26’th-27’th, February 2002, ETSI, Sophia Antipolis, France. Outline. Background The Challenge: Emergency Services over the Internet
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Future Emergency Telecommunication Scenarios over the Internet Dr. Ken Carlberg k.carlberg@cs.ucl.ac.uk Emergency Telecommunications Workshop 26’th-27’th, February 2002, ETSI, Sophia Antipolis, France
Outline • Background • The Challenge: • Emergency Services over the Internet • Services & Protocols • Operational Scenarios • Usage Scenarios • Summary
Background: Internet • A network of networks • Self autonomy • Minimal requirements to be an ISP • May use routing protocols • May use non-FIFO queues • No traffic engineering requirements • Most congestion occurs at access points • Tier-1 ISPs usually have high excess capacity at exchange points • U.S. centric view at times • Counter example includes Trans-Atlantic link(s)
Background: Internet (2) • Default service model is Best Effort • “send and pray” • No minimal level of QoS • TCP is ~90-95% of traffic load • Adaptive to congestion, but cost is degraded service • Security is an issue with IP networks • Denial of service: NIMDA, ICMP Echo Request, … • Spoofing
Challenge • Distinguish emergency traffic • Provide separate level of service • Policy and/or regulatory issue • Value added services • Alternate path routing • Interoperation with PSTN • Mapping code points (at a minimum) • Achieving the above with minimal changes to existing IP protocols
Services & Protocols • Past, Current, and/or On-Going (sample set) • SIP/Megaco/H.323 • MPLS • Diff-serv • Int-Serv/RSVP • Instant Messaging & Presence • Other • WFQ • RED
Observations • Existence of protocols does NOT equate to availability by vendors or service providers • MPLS • Local domain service • Complex and possibly overkill for many ISPs • Int-Serv/RSVP • Market rejection of end-to-end model • Diff-serv • Local domain service • Basic (AF) service can be accomplished with WFQ/RED So,….be a pessimist about what exists, and leverage what you can use
IP Backbone IP as a private network Single control of resources Single-Hop ISPs No Inter-ISP SLAs Single control of resources Stub IP Domain Internet VoIP PSTN PBX VoIP with QoS: Near Term Telcos SS7 Evolution towards NGN SS7 Signaling VoIP (SIP/H.323 over IP) WFQ ISP Cloud Client IP Stub PSTN ISP Cloud Client IP Stub Diff-Serv (AF)
ETS Operation: Near Term • Label calls for ETS • SIP Resource Field (draft) • H.323 Priority Field (draft) • Policy defines actions (part of SLA) • Preemption / non-preemption • Traffic engineered paths • SLA’s dictate usage (e.g., diff-serv code points) • e.g., #1) AF (Class 1) for Signaling, EF for VoIP • e.g., #2) AF (Class 3) for Signaling & VoIP • Access control at the edge
Network View SIP Server TRIP View TRIP Route ETS Operation: Mid Term • Alternate path routing • BGP could not support Emergency attribute • Routers straining to support number of routes • Convergence time problem • Application Layer routing • e.g., Telephony Routing over IP (TRIP)
Admission Control Call/Data (1) (emergency) Call/Data (2) • Potential augmentation • New code point to distinguish emergency EF from normal EF Admission Control Call/Data (1) (emergency) Call/Data (2) ETS Operation: Mid Term (2) • Admission Control • Performed at edge of diff-serv domain • Core/Internal congestion • AF: use drop precedence • EF: requires careful traffic engineering to avoid congestion
ETS Usage • Traveling Authentication & Capability • Similar to GETS • Non-ubiquitous service • ETS “islands” connected via best effort service • Goal is ever increasing wide spread support • Payment and/or regulation are important issues because…. …..“There is no such thing as a free lunch”
ETS Future? • QoS Gateways • Forward Error Correction (FEC) • Redundant transmission • Transcoding • Semi-Active Networking • Very leading edge approach • E.g., Cisco Intelligence Engine 2100 • XML/policy based control of network elements • Negotiated service with user • Degraded service if admission control fails
Summary • Autonomous & independent nature of IP networks makes support of ETS difficult • Be pessimistic about available services • “We” probably have 85% of what is needed to supporting ETS • More options will exist for the ETS user