Transcript Internet QoS for IPv6

Mechanisms for Providing QoS in IPv6-based Internetworks
Jun-Hyun, Moon
Computer Communications LAB.,
Kwangwoon University
[email protected]
Introduction to the QoS in the context of IP Networking
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QoS(Quality of Service)??
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Service Differentiation
Bandwidth Guarantee
Low Delay
Low Jitter
Low loss
Introduction to the QoS in the context of IP Networking (cont.)
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Best-Effort Delivery Model
 irrespective of content-type or application requirements.
 Simple principle - First Come, First Served (FCFS)
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Integrated Services (IntServ) Model
 Three service class
 Best Effort service – FCFS, ordinary data : default
 Guaranteed service – Hard Real-time requirements
 Controlled Load service – Soft Real-time requirements
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Differentiated Services (DiffServ) Model
 ‘Per-Flow-based’ QoS support
 ‘Aggregated-Flow-based’ QoS support
 Per-Hop-Behavior (PHB)
The Facts
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There’s tendency towrds All-IP network:
 Fast adoption of IP-based communications for hand-held
wireless interfaces.
 Users expect access to advanced internet services as if they
were on traditional fixed networks.
IPv6 QoS: Generic Issues
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IPv6 기본 헤더 구조
IPv6 QoS: Generic Issues(cont.)
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Traffic Class bit (8bit) : Class or Priority Identifier
 RFC 1881
 0 ~ 7 : congestion-controlled traffic
 8 ~ 15 : Non-congestion-controlled traffic
High
priority
IPv6 QoS: Generic Issues(cont.)
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QoS Management
IPv6 QoS: Generic Issues(cont.)
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QoS Management
IPv6 QoS: Generic Issues(cont.)
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Flow Label (20bit)
 송신자 Node에서 할당
 Flow
 송신자 IP 주소와 Non-zero flow label의 조합으로 유일하게 식별
 같은 Flow에 속하는 모든 Packet들은 the same source
address, destination address, and flow label
 The source desires special handling by the intervening routers.
 Experimental and subject to change
IPv6 QoS: Generic Issues(cont.)
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Example
The Mobility Problem
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Purposes from the QoS points of view:
 Providing the requested services even if the terminal changes its
point of attachment to network.
 Deal with handovers, change of IP addresses, inter-domain mobility,
etc.
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Mobile IP problems:
 Triangular routing-problem, packets go up and down-stream through
different paths.
 Frequently path updates: high overhead, high latency, high loss.
 Need of CCOA addresses per host.
 Use of tunnels which affects QoS provision.
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Mobile IPv6:
 Solves most of the problems of Mobile IP.
 No seamless mobility, frequent path updates which still causes high
overhead, latency and loss during handover.
Micro-mobility
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Micro-mobility, Domain-mobility, Regional-mobility???
 It manages movement within the same administrative domain.
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Advantages of using Micro-mobility with Mobile IP:
 Path updates within domain → micro mobility protocol..
 Reduces Mobile IP path updates.
 Inter-domain handovers are faster.
Effects of Micro-mobility in QoS
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Effects of Micro-mobility in QoS
Using IPv6 for Micro-mobility
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IPv6 Advantages.
 Micro-mobility protocols can make use of most of the
advantages of IPv6
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Using IPv6 within the Micro-mobility domain:
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Use of extension headers.
Security.
Auto-configuration.
Tunneling with source address options.
Movement detection.
No tunneling → avoid encapsulation.
QoS extensions (not of use of mm protocol but useful for this
duscussion).
Cellular IP
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Cellular IP
IPv6 applied to Cellular IP
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Changes introduced by using IPv6 on Cellular IP:
 Route update packets are included on a IPv6 control header.
Route caches are updated with every packet.
 Security added for authentication.
 Autoconfiguration to obtain COA directly.
 No additional IP addresses are introduced. Only IPv6
addressing mechanisms are used.
 Route optimization included for IPv6
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QoS aspects:
 the same given by using IPv6: performance, flowid, DSCP.
 Given by performance improvements on mobility itself.
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Cellular IPv6:
 <draft-shelby-seamoby-cellularipv6-00.txt>.
So…
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Mobile IP provides basic mobility.
Mobile IP has been greatly improved with IPv6(MIPv6)
Micro-mobility protocols optimize mobility.
 most of them do not make use of IPv6.
“IPv6 can be succesfully applied to existing
Micro-mobility protocols to improve their
operation.”
But….
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That’s of enough for QoS.
Things needed for our QoS purposes:
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Fast handover → IETF mobileIP group, IETF seamoby group.
Minimum packet loss → soft handover.
Bounded impact on delay → Micro-mobility approaches?
Uniform level of service (end to end) → within the same cell
→ standarized support from the link layer so adaptation can
be possible.
QoS service is a contract that the system need to
predict, and that’s not possible now.
“There’s still a lot of things to do to provide
‘good’ QoS when the terminal is moving”