1

Kommunikatsiooniteenuste arendusIRT0080

Loeng 12, “ IP v6 + QoS”

Avo Otstelekommunikatsiooni õppetool,

TTÜ raadio- ja sidetehnika inst.avo.ots@ttu.ee

2

IPv6• Redefine functions of IP (version 4)

– What changes should be made in….• IP addressing

• IP delivery semantics

• IP quality of service

• IP security

• IP routing

• IP fragmentation

• IP error detection

3

IPv6• Initial motivation: 32-bit address space soon to be

completely allocated (est. 2008)• Additional motivation:

– Remove ancillary functionality• header format helps speed processing/forwarding

– Add missing, but essential functionality • header changes to facilitate QoS • new “anycast” address: route to “best” of several replicated servers

IPv6 datagram format:

– fixed-length 40 byte header

– no fragmentation allowed

4

IPv6 Header (Cont)

Priority: identify priority among datagrams in flowFlow Label: identify datagrams in same “flow.” (concept of“flow” not well defined).Next header: identify upper layer protocol for data

5

IPv6 Changes• Scale – addresses are 128bit

– Header size?

• Simplification– Removes infrequently used parts of header– 40 byte fixed header vs. 20+ byte variable header

• IPv6 removes checksum– IPv4 checksum = provide extra protection on top of

data-link layer and below transport layer– End-to-end principle

• Is this necessary?• IPv6 answer =>No

– Relies on upper layer protocols to provide integrity– Reduces processing time at each hop

6

IPv6 Changes• IPv6 eliminates fragmentation

– Requires path MTU discovery

• ICMPv6: new version of ICMP– additional message types, e.g. “Packet Too Big”– multicast group management functions

• Protocol field replaced by next header field– Unify support for protocol demultiplexing as well as option

processing

• Option processing– Options allowed, but only outside of header, indicated by

“Next Header” field– Options header does not need to be processed by every router

• Large performance improvement• Makes options practical/useful

7

IPv6 Changes• TOS replaced with traffic class octet

– Support QoS via DiffServ

• FlowID field– Help soft state systems, accelerate flow classification– Maps well onto TCP connection or stream of UDP

packets on host-port pair

• Easy configuration– Provides auto-configuration using hardware MAC

address

• Additional requirements– Support for security– Support for mobility

8

Transition From IPv4 To IPv6• Not all routers can be upgraded simultaneous

– no “flag days”– How will the network operate with mixed IPv4 and

IPv6 routers?

• Two proposed approaches:– Dual Stack: some routers with dual stack (v6, v4) can

“translate” between formats– Tunneling: IPv6 carried as payload in an IPv4

datagram among IPv4 routers

9

TunnelingA B E F

IPv6 IPv6 IPv6 IPv6

tunnelLogical view:

Physical view:A B E F

IPv6 IPv6 IPv6 IPv6IPv4 IPv4

10

TunnelingA B E F

IPv6 IPv6 IPv6 IPv6

tunnelLogical view:

Physical view:A B E F

IPv6 IPv6 IPv6 IPv6

C D

IPv4 IPv4

Flow: XSrc: ADest: F

data

Flow: XSrc: ADest: F

data

Flow: XSrc: ADest: F

data

Src:BDest: E

Flow: XSrc: ADest: F

data

Src:BDest: E

A-to-B:IPv6

E-to-F:IPv6

B-to-C:IPv6 inside

IPv4

B-to-C:IPv6 inside

IPv4

11

Dual Stack Approach

• Dual-stack router translates b/w v4 and v6– v4 addresses have special v6 equivalents– Issue: how to translate “FlowField” of v6 ?

12

QoS• Pakettvõrkudes liikluse korralduse (traffic

engineering) mõiste “garanteeritud teenuse kvaliteet” (QoS, Quality of Service) tähendab tõenäosuslikku hinnangut, et sidevõrk jälgib liikluslepet.

• Paljudel juhtudel kasutatakse QoS tõenäosusena, et pakett läbib võrku saatjast vastuvõtjani oma ettemääratud ajavahemiku jooksul.

13

Teenusekvaliteedi aspektidQoS – Quality of Service

ITU-T E.800 Recommendation

14

Teenusekvaliteedi aspektid (2)

Teenuse Kättesaadavus

(Accessibility)

TeenusePüsivus

(Retainability)

TeenuseTerviklikus

(Integrity)

QoS

QoS parameetrid QoS parameetrid QoS parameetrid

15

Teenusekvaliteedi aspektid (3)

• Iga teenuse jaoks oma nõuded

• QoS profiil

• Erinevad teenusekvaliteedi tasemed vastavalt nõuetele

16

Introduction• Coexistence of heterogeneous networks

– Home networks, WLAN, 2G/3G, Campus-wide, satellite, …

– The development of multimode handsets is a major challenge

– Currently discussed standards fall short– Tomorrow user’s will expect the technology structure to

“disappear” and be of no concern

• Network architecture designed by IST project Daidalos– Provide seamless services accessible anytime anywhere

across heterogeneous technologies– Enhanced Mobile IPv6 platform for mobility and QoS– Support for optimized mobility– Integration with QoS resource management

17

Sensor Integration

Platform

Administrative Domain 2

t

Access Network 13

Service Provisioning Platform 1

Access Network 12

Access Network 11

Core Router

Core Router

Core Router

Access Router

Access Router

Mobile IP

Routing (Ad-hoc)

QoS Agent

Registration Agent

Metering

Accounting

Charging

Key Management

SIP User Agent

SD&C Agent

Security Support

(Content Adaptation)

AnQoS BrokerMMSP Paging Agent

PBNMSA4CCnQoS BrokerHA

KDC CMSMMSPP

Edge Router

QoS Manager

Monitoring

Accounting

Adv. Router Mech,

Metering

QoS Manager

Ntw Monitor & Meter

Fast Handover

Accounting

Authorization

Adv. Router Mech.

QoS Manager

Monitoring

Accounting

Adv. Router Mech,

Metering

Authorization

Key Interconnection

(3P)SP Applications/Content

Service Platform 1

Fe

de

ratio

n/S

LA

Bridge Mesh and/or Hierarchical PKI

Service Composer

AccessPoint

Access Router

AccessPoint

AccessPoint

Currently used link

Candidate links

Mobilerouter

DPA

Mobile Network

Service Composer

MANET

Service Register

GPSlocation

Temperature

Health+Body

Sensor

InertiaCube

SecuritySensor

NoiseLevel

LightingSituation

ProximitySensor

SoftwareSensors

Activity(phone/mouse)

Lighting

GPSlocation

Temperature

Health+Body

Sensor

InertiaCube

SecuritySensor

NoiseLevel

LightingSituation

ProximitySensor

SoftwareSensors

Activity(phone/mouse)

Lighting

Location

Location

CAN

PerSP

PerSP

18

Mobile Terminal

IAL

DVB-T MBMSTD-CDMA

WLAN WiMAX

QoSAL

UDLR

QoSCMTC

IISUserGUI

CARD FHO

IPv6++/MIPv6/Multicast

Technologies

TerminalIntelligence

QoS

Handover

19

Access Router / Access Point

DVB-T MBMSTD-CDMA

WLAN WiMAX

QoSAL

UDLR

QoSMCARD PA

Technologies

TerminalIntelligence

QoS

NetworkIntelligenceAM

MM

FHO CT D&M

Handover

IPv6++/

MIPv6/PIM

ENC

20

Handover

• Mobile Initiated Handover

• Network Initiated Handover

Triggered

• At startup

• Upon losing signal

Accounts for

• user preferences

• candidate APs load (QoS)

• signal strengths

Triggered by

• Overloaded AP (QoS)

• losing signal

Accounts for

• signal strengths of MTs

• APs load (QoS)

21

Wi-Fi Alliance Roadmap[Amer Hassan, Microsoft, jaanuar 2005]

Baseline

Security

QoS

Applications

Q1 Q2 Q4Q32005

802.11e

WMMScheduled Access

Public Access CEPhase2

2004

Extended EAP

2006

802.11h+d

Simple Config

Voice/Wi-FiWCC

802.11j 802.11k

CEPhase1

WMM Power Save

22

QoS vajadus• QoS vajadus esmases tähenduses tuleneb

video ja suure edastuskiirusega (mobiilsetest) andmesessioonidest

• Lõplikult kavatsetakse realiseerida standardina IEEE 802.11n, vahevariant realiseeriti standardina IEEE 802.11e, mida toetab Proximi AP-4000.

23

802.11e• The 802.11e is a working group charged with

making changes to the MAC layer to allow for QoS (Quality of service) in WLAN– Formally: “The purpose of Task Group E is to: Enhance

the current 802.11 MAC to expand support for applications with Quality of Service requirements, and in the capabilities and efficiency of the protocol.”

• The standard is in a late draft (draft 13 at this time) form and expected to be rectified this year.

• Implements two main methods of QoS control– Extended DCF – also implemented as WMM– HCF – Hybrid Coordination function – uses PCF

functions and only available as part of the final 802.11e spec

24

802.11e EDCF/WMM queues• WMM is an interim spec on the way to 802.11e

implementing only eDCF• EDCF is based on using different contention

parameters (CW) to differentiate queues• WMM has 4 priority levels and queues:

– Audio/real time

– Video

– Best effort

– Background

• EDCF will support 8 priority levels but still 4 queues

25

Roadmap – WLAN

26

Linkhttp://www.lr.ttu.ee/~avots/Introduction_to_IPv6.ppt