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Information Services over IP
Link-layer and network information Part of IEEE 802.21 Handover Services IS server may not be adjacent link-layer
entity. Allow deployment of IS transported over IP draft-faccin-mih-infoserv-01.txt
– G. Daley, S. Faccin, Q. Xie, E. Hepworth. Some Requirements for a Handover Information Service
Information Services Over IP
One of the handover services
MobilityService 1 Information
Service
MobilityService 2
Mobility Services Delivery Protocol
IP
MobilityServiceSignalingLayer
MobilityServiceTrans/ApplLayer
Handover Information Services
• A platform for exchanging physically or topologically local information
• Assistance of handover planning• Optimize channel and base station selection• Dependent on quality of information
exchanged• Explicitly requires management(!)
Handover Information Services
IS ISQuery Query
Query
Query
Mobile Server
IS
IS IS
AP
Movement
AP
AP
AP
Information Services Characteristics
Non-real time Informational flows (not controls or events) Primarily request/response
– Push possible– Events separate.
Scope of work
Needs to be discussed with 802.21– Different roles to be negotiated.
Seems to be three tasks (at least) Server/Service Discovery Security Transport
– Transport Layer Services– Network Layer requirements
Information Service Message Exchanges
MobileIS Client
IS Server
1) IS Server Discovery
2) IS Server Address3) Contact Server4) SA Bootstrap
5) IS Query
6) IS Response
Directoryor Group
Three Phases: Discovery, SA Bootstrap, Request/Response
Information Service Scenarios
IS Server on same IP hop Remote Device beyond IP hop Needed? (802.21?)
Information Service Scenarios
Information sourced from different locations Different IS Servers for different roles
HLI
LLI
Requirements (Guesses): 1
You’ve already read these in the draft. Really relies on firm requirements from 802.21 Some interesting ones:
– Provide information service transport mechanism which works of IPv4 and IPv6
– Allow multiple packet responses– Robust query/response on wireless networks– Distinguish between packet source and query source (allow
proxies)– Provide NAT traversal for IPv4 (off-link?)
Requirements (Guesses): 2
– Describe IS discovery mechanisms for IPv6– Describe IS discovery mechanisms for IPv4– Provide common discovery (even if server is AP,
Router or off-link?)– Protect discovery mechanism?
Alternatively, rely on SA bootstrap
– Allow distinct classes of Information Services to be discovered
– Allow multiple servers to be discovered
Requirements (Guesses): 3
– Common SA negotiation regardless of server location
– Provide confidentiality for queries and responses– Provide identity protection against eavesdroppers
for querier– Protect IS Server and discovery resources from
DoS.
Transport Issues
Response Timing Constraints Stream or Datagram Oriented Reliability in Transport or above
Discovery Issues
Single or multiple discovery methods Information Server participation in discovery IS Servers’ own use of discovery
– Recursive discovery of Information Services?
Only one server, or one server per class
Security Issues
Mutual authentication requirements IS-Server to IS-Server SA requirements Rate limitation of queries Session or host-based SAs
Handover Services
• All being developed in IEEE 802.21• Event services
– Link-layer indications– e.g. link-layer availability for data service
• Command Services– Control of network state by remote devices– e.g. instruction to change channel near tunnel
• Information Services– Information for planning handovers (continued…)