Transcript PPT Version

Some use cases and requirements
for handover Information Services
Greg Daley
MIPSHOP Session
IETF 64
Information Services over IP
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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
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G. Daley, S. Faccin, Q. Xie, E. Hepworth. Some
Requirements for a Handover Information Service
Information Services Over IP
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One of the handover services
Mobility
Service 1
Mobility
Service 2
Information
Service
Mobility Services Delivery Protocol
IP
Mobility
Service
Signaling
Layer
Mobility
Service
Trans/Appl
Layer
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
AP
Mobile
IS
Server
Query
IS
AP
Query
IS
Query
Movement
AP
AP
IS
Query
IS
Information Services Characteristics
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Non-real time
Informational flows (not controls or events)
Primarily request/response
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Push possible
Events separate.
Scope of work
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Needs to be discussed with 802.21
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Different roles to be negotiated.
Seems to be three tasks (at least)
Server/Service Discovery
Security
Transport
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Transport Layer Services
Network Layer requirements
Information Service Message
Exchanges
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Three Phases: Discovery, SA Bootstrap,
Request/Response
1) IS Server Discovery
Mobile
IS Client
Directory
or Group
2) IS Server Address
3) Contact Server
4) SA Bootstrap
5) IS Query
6) IS Response
IS Server
Information Service Scenarios
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IS Server on Link-layer peer
May not need IP
Information Service Scenarios
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IS Server on same IP hop
Perhaps on router
Information Service Scenarios
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IS Server on same IP hop
Remote Device beyond IP hop
Needed? (802.21?)
Information Service Scenarios
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Information sourced from different locations
Different IS Servers for different roles
HLI
LLI
Requirements (Guesses): 1
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You’ve already read these in the draft.
Really relies on firm requirements from 802.21
Some interesting ones:
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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
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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?
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Alternatively, rely on SA bootstrap
Allow distinct classes of Information Services to
be discovered
Allow multiple servers to be discovered
Requirements (Guesses): 3
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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
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Response Timing Constraints
Stream or Datagram Oriented
Reliability in Transport or above
Discovery Issues
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Single or multiple discovery methods
Information Server participation in discovery
IS Servers’ own use of discovery
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Recursive discovery of Information Services?
Only one server, or one server per class
Security Issues
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Mutual authentication requirements
IS-Server to IS-Server SA requirements
Rate limitation of queries
Session or host-based SAs
Thankyou
EXTRA SLIDES
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…)