Transcript 슬라이드 1

Quality of IPv6 Service : To be considered
Hyun-Kook Kahng
Korea University
[email protected]
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Contents
QoS in IP network
IPv6 QoS
QoS Signaling Protocols
Conclusions
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QoS
 QoS means providing consistent, predictable data delivery
service, satisfying end-user requirements.
 The problematic
 Standardization
 QoS will only be guaranteed under an End to End basis
 Migration from IPv4 to IPv6
 This process will affect to the QoS through the adequate use of the IPv6 fields
 Backbone dimensioning
 As users begin to demand QoS features, the dimensioning of the internal infra
structure, will have to be upgraded.
 Adequate interplay among the different QoS enabling technologies
 Especially by specifying coherence along the different protocol layers that avo
id counterworking among the solutions proposed.
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General QoS Principles
 Integration
Challenge !
 Separation
Challenge !!
 Transparency
 Multiple Time scale
 Performance
 Simplicity
 Scalability
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Protocol Stacks
E-mail, FTP, Web
TCP/UDP/RTP
E-mail, FTP, Web, AV conferencing, etc
RSVP, DiffServ
TCP/UDP/RTP
Signaling
Application
NSIS SP
Signaling TP
IPv4 (MIPv4)
IPv6, MIPv6
Ethernet
IEEE 802.11, MPLS, etc
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Mechanisms for supporting QoS requirements
E-mail, FTP, Web, AV conferencing, etc
Congestion Control
Congestion Avoidance
Flow Control
Error Control
Authentication
Admission Control
Resource Management
Policing
Flow labeling, Queue management,
Traffic Shaping, Security, Mobility
Labeling, Mobility, Security
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QoS Enabling Technologies
QoS Enabling Technologies
Metrics
Mechanisms
•Availability
Throughput
•Bandwidth
•Packet Loss
•Delay/Latency
•Jitter
•Security
•Packet Classification
•Queuing & Scheduling
•Mapping
•Traffic Conditioning
•Rate Limiting & Shaping
•Optimization, Tuning(e.g., TCP)
Traffic & Network
Management
• Performance measurement
• Traffic monitoring
• Traffic engineering
- Congestion Control
- Flow Control
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QoS requirements for certain types of service
Varied sensitivities of network data types
Traffic Type
Sensitivities
Bandwidth
Loss
Delay
Jitter
Voice
Very low
Medium
High
High
E-commerce
Low
High
High
Low
Transactions
Low
High
High
Low
E-mail
Low
High
Low
Low
Telnet
Low
High
Medium
Low
Casual browsing
Low
Medium
Medium
Low
Serious browsing
Medium
High
High
Low
File transfers
High
Medium
Low
Low
Video conferencing
High
Medium
High
High
Multicasting
High
High
High
High
[source 1 ]
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QoS User Requirements
Premium
Basic
Interactive
Real Time
Non-Interactive
Real Time
NonReal Time
Delay
150ms
300ms
200 ms
Jitter
3 ms
50 ms
best effort
Loss
1%
1%
2%
Guarantee
99%
99%
98%
Delay
400ms
600ms
500ms
Jitter
3 ms
100 ms
best effort
Loss
4%
5%
5%
Guarantee
95%
95%
92%
[source 2 : EURESCOM ProjectP906]
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IPv4 vs IPv6
bit
0
8
Version
IHL
16
24
Service Type
Identifier
Time to Live
Total Length
Flags
Protocol
bit
0
31
4
Version
Fragment Offset
12
Class
16
24
31
Flow Label
Payload Length
Next Header
Hop Limit
Header Checksum
32 bit Source Address
128 bit Source Address
32 bit Destination Address
Options and Padding
IPv4 Header
128 bit Destination Address
20 octets, 12 fields, including 3 flag bits
+ fixed max number of options
Changed
Removed
IPv6 Header
40 octets, 8 fields
+ Unlimited Chained Extension (options) Header
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IPv6-only QoS
 Originally Best-Effort service through FCFS by a single packet
Queue
 Daisy chain of “Headers”
 Flow-Label
 Redefinitions Flow Label
 Hybrid
 Modified Hop-by-Hop Extension Header
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Redefinition of IPv6 Flow Labels (1)
 DS with PHB Id
 Following format can be used for the Flow Label:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
0
1
Pseudo - Random value
Per Hop Behavior Ident. Code
reserved
 DS with multi field classifier
 The Flow Label classifier is basically a 3-element tuple
 Port number and H-to-H protocol
 The algorithmic mapping of the port numbers and protocol into the Flow
Label.
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Server port number
H-to-H protocol
[Source 3 : draft-conta-ipv6-flow-label-02.txt]
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Redefinition of IPv6 Flow Labels (2)
 TCP & UDP port
 Using TCP server port number
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
TCP Server port number
reserved
0
 Using UDP server port number
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
UDP Server port number
1
reserved
 IPv6 headers length
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Length of IPv6 headers
H-to-H protocol
[source 3 :draft-conta-ipv6-flow-label-02.txt]
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Redefinition of IPv6 Flow Labels (3)
 Hybrid
 000 Default
 001 Random number
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
0 0 1
 010 Hop-by-Hop extension header
 011 MFC
Pseudo-Random value
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
0 1 0
0
1
2
Don’t care
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0 1 1
 100 Port # and TCP/UDP
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5
6
7
8
9 10 11 12 13 14 15 16 17 18 19
Per Hop Behavior Ident. Code
R
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
1 0 0
TCP Server port number
0
 101 New definition
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
1 0 1 0
1 0 1 1
Flow Label (Soft)
Flow Label (Hard)
[source 4 : draft-banerjee-flowlabel-ipv6-qos-03.txt]
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QoS Signaling Protocols
 Bandwidth Management Algorithms/Schemes
QoS Net
Most
App
X
Provisioned resources end-to-end (e.g. private, low-traffic network)
X
X
RSVP [IntServ Guaranteed] Service (provides feedback to application)
X
X
RSVP [IntServ Controlled] Load Service (provides feedback to application)
X
Least
Description
Multi-Protocol Label Switching (MPLS)
X
X
Differentiated Services applied at network core ingress appropriate to
RSVP reservation service level for that flow.
X
X
DiffServ or SBM applied on per-flow basis for source application
X
DiffServ Applied at network core ingress
X
Fair queuing applied by network elements (e.g. CFQ, WFQ, RED)
Best effort service
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RSVP & DiffServ (1)
 RSVP
 More than expected [source 5 ]
 Policy and Shaping increase the data path latencies [source 6,7]
 DiffServ
 Queuing Algorithm
 Priority Queuing
 WFQ
 (W)RED
 PHB
 EF & AF for UDP traffic
 AF not optional for TCP traffic
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RSVP & DiffServ (2)
 Interoperation of RSVP & DiffServ
 RSVP + DiffServ with Priority Queuing
 RSVP + Best-Effort
 Bandwidth Broker
 DiffServ Admission Control
 Aggregated Flow demand based AC
 Measurement based AC
 Congestion information
 Probe packet
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Boomerang - A simple RSVP





Simple Implementation
Small Processing Load in Routers
Fast Reservation Setup
Low Protocol Overhead
No requirements on the Far-end Node
Diff-Serv
B
E
D
A
C
B’
Far-End Node
Initiating Node
[source 8: http://www.cs.inf.ethz.ch/37-235/studentprojects/farkas.pdf ]
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YESSIR - YEt another Sender Session Internet Reservations




IntServ Model
Sender-initiated reservation
Robustness and soft-state
Allow partial reservations
Provide different reservation styles
YESSIR
RSVP
RTCP
 Individual / Share
 Low protocol and processing overhead
 Interoperable with RTP and IntServ model
 Provide link resource advertising functions
RSVP
(raw mode)
UDP
IP MODE
(with router-alert option support)
Network Interface
[source 9]
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INSIGNIA
 Very simple signaling mechanism for supporting QoS in mobile
ad-hoc networks
 Adaptive Services for continuous Media Flow and Micro-Flow
support
 Separation of Routing, Signaling and Forwarding
 In-Band Signaling
 Soft-State Management
[source 10]
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Conclusions
 All protocols and mechanisms should be revisited for QoS.
 ITU-T
X.641 QoS Framework, X.642 QoS Methods and Mechanisms
E-mail, FTP, Web, AV conferencing, etc
TCPng / UDP+
RSVP, DiffServ, RSVP-Lite,
DiffServ+
IPv6 with “careful implementation”
IEEE 802.11, MPLS, 3G/4G, etc
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reference
 [source 1] B.Koch(AQUILA), D.Goderis(TEQUILA), R.Philips(TOREENT), Cisco, NGN-I
Briefing Paper on QoS for IP Networks
 [source 2] EURESCOM ProjectP906
 [source 3] IETF, draft-conta-ipv6-flow-label-02.txt
 [source 4] IETF, draft-banerjee-flowlabel-ipv6-qos-03.txt
 [source 5] Martin karsten, Jens Schmitt, and Ralf Steinmetz. Implementation and Evaulation of
the KOM RSVP Engine. In Proceedings of the 20th Annual Joint Conference of the IEEE
Computer and Communications Societies(INFOCOM'2001), April 2001, pp1290-1299
 [source 6] Tsipora Barizilai, Dilip Kandlur, Debanjan Saha, Ashish Mehra, Steve Wise; Design
and Implementation of an RSVP-based Quality of Service Architecture for Integrated Computing
Systems (ICDCS'97)
 [source 7] Roberto Canonico, Simon Pietro Romano, Mauro Selitto, and Giorgio Ventre A
Scheme for Time-Depedent Resource Reservation in QoS-Enabled IP Networks, Springer LNCS
1815, pp.81
 [source 8] http://www.cs.inf.ethz.ch/37-235/studentprojects/farkas.pdf
 [source 9] [PaSc98] Ping Pan, Henning Schulzrinne, "YESSIR: A Simple Reservation
Mechanism for the Internet". In the Proceedings of NOSSDAV, Cambridge, UK, July 1998.
 [source 10] http://comet.ctr.columbia.edu/insignia/
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