Some use cases and requirementsfor handover Information Services

Greg DaleyMIPSHOP SessionIETF 64

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 Link-layer peer May not need IP

Information Service Scenarios

IS Server on same IP hop Perhaps on router

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

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…)