performance evaluation of sctp in wireless networks tutors: tania jimenez and yezekael hayel
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Performance Evaluation of SCTP in wireless networks Tutors: Tania Jimenez and Yezekael Hayel VICUNA, Nelson. Introduction. Wireless Networks. SCTP. NS2. Performance Evaluation. Conclusion. Planning. Performance Evaluation of SCTP in wireless networks VICUNA, Nelson. Introduction. - PowerPoint PPT PresentationTRANSCRIPT
Performance Evaluation of SCTP in wireless networks
Tutors: Tania Jimenez and Yezekael Hayel
VICUNA, Nelson
Planning
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Introduction
Wireless Networks
SCTP
NS2
Performance Evaluation
Conclusion
Introduction
Most of the variants TCP offer good benefits in wired networks, based on the assumption that most of the losses were due to the congestion.
But in a wireless network, packet losses are mainly due to high rates of losses caused by bit poor conditions spread.
Additionally, wireless networks have certain characteristics such as high latency, high packet loss and bandwidth variable posed conflicts of the abilities of TCP.
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Wireless Networks, i
Several advantages
Mobility
Allows transmit real-time information anywhereto anyone
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Deployment
Flexibility
They can go where cable can not
Wireless Networks, ii
Properties
High bit-error rate (BER): random loss
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Bursty traffic: mixed voice/data, channel access problems
Disconnections: handoffs, interferences
Impact on TCP: Fast retransmit, timeouts, large and varying delay.
Wireless Networks, iii
Commonly used wireless networks
IEEE 802.11Standard for wireless LANs, ratified by the Institute of Electrical and Electronics Engineers (IEEE) in the year 1997.
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
WiMAX (Worldwide Interoperability for Microwave Access)Standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL.
UMTS (Universal Mobile Telecommunications System)The intention is to create and extend the capability of today’s mobile, cordless and other satellite technologies using the Global System for Mobile communication (GSM) core infrastructure.
SCTP, i
Stream Control Transmission Protocol
Transport protocol, designed by the Signaling Transport (SIGTRAN) group of the Internet Engineering Task Force (IETF)
Message-oriented protocol with all the necessary TCP-like mechanisms
SCTP provides sequencing, flow control, reliability and full-duplex data transfer like TCP
SCTP has unique features including multihoming and multistreaming
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Originally designed to support PSTN signaling messages over IP Networks
SCTP, iii
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
IP reference model
SCTP, TCP and UDP
Packet Format
Association
SCTP, iii
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
IP reference model
SCTP, TCP and UDP
Packet Format
Association
Protocol Feature SCTP TCPUDP
State required at each endpoint yes yes no
Reliable data transfer yes yes no
Congestion control and avoidance yes yes no
Message boundary conservation yes no yes
Path MTU discovery and message fragmentation yes yes no
Message bundling yes yes no
Multihomed hosts support yes no no
Multistream support yes no no
Unordered data delivery yes no yes
Security cookie against SYN flood attack yes no no
Built-in heartbeat (reachability check) yes no no
SCTP, iii
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
IP reference model
SCTP, TCP and UDP
Packet Format
Association
SCTP, iii
IP reference model
SCTP, TCP and UDP
Packet Format
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Association
SCTP, iv
Congestion Control
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Slow-start
Congestion Avoidance
Fast Retransmit
SCTP, v
Differences from TCP Congestion Control
cwnd, the initial congestion window, is suggested to be 2*MTU in SCTP, which is usually one MTU in TCP
In SCTP, the increase of the cwnd is controlled by the number of acknowledged bytes; while in TCP, it is controlled by the number of new acknowledgement received.
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
In SCTP, fast retransmission is triggered by the fourth missing report of a chunk; while in TCP, three duplicate ACK triggers fast retransmission
SCTP has no explicit fast recovery algorithm that is used in TCP
NS-2, i
Network SimulatorDiscrete-time simulator whose development began in 1989with the development of REAL Network Simulator
SCTPThe SCTP module for NS-2 has been contributed by agroup at the University of Delaware
Supports some features of RFC 2960 (with draft-ietf-tsvwg-sctpimpguide-04.txt)
Distribution has General Public License (GPL) condition
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
NS-2, ii
SCTP structure in NS-2
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Performance Evaluation and Analysis, i
Schemas
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Wired Network
802.11
UMTS
WiMAX
Performance Evaluation and Analysis, ii
Topologies
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Wired Network
100Mbps
100Mbps
100Mbps
100Mbps
1Mbps
100Mbps
100Mbps
N1(1)
n1N1(2)
N1(m)
n0
N0(1)
N0(2)
N0(n)
bottleneck
Performance Evaluation and Analysis, ii
Topologies
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
802.11, UMTS and WiMAX
100Mbps
100Mbps
100Mbps
1Mbps
N1(1)
n1N1(2)
N1(m)
bottleneck
BS
N0(1)
N0(2)
N0(n)
Performance Evaluation and Analysis, iii
Measure variables
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Throughput
Delay
Packet loss
Average of data per second per client delivered over the bottleneck
Average of time that a packet of data takes from the origin to the destination
Packet loss due to network congestion.
Performance Evaluation and Analysis, iv
Experimental scenario
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
FTP transmission with different numbers of clients in wireless networks stable state (no packet loss for link conditions)
FTP transmission with a fixed number of clients (50) withdifferent rates of packet loss in wireless networks
Performance Evaluation and Analysis, iv
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Loss Rate
Throughput
Delay
Experimental Scenario 1
Number of Clients: 1, 5, 10, 25, 50 and 100
Performance Evaluation and Analysis, iv
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Loss Rate
Throughput
Delay
Experimental Scenario 1
Number of Clients: 1, 5, 10, 25, 50 and 100
Performance Evaluation and Analysis, iv
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Loss Rate
Throughput
Delay
Experimental Scenario 1
Number of Clients: 1, 5, 10, 25, 50 and 100
Performance Evaluation and Analysis, iv
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Loss Rate
Throughput
Delay
Experimental Scenario 2
Link Error, in %: 0, 5, 10, 25 and 50
Performance Evaluation and Analysis, iv
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Loss Rate
Throughput
Delay
Experimental Scenario 2
Link Error, in %: 0, 5, 10, 25 and 50
Performance Evaluation and Analysis, iv
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Loss Rate
Throughput
Delay
Experimental Scenario 2
Link Error, in %: 0, 5, 10, 25 and 50
Conclusion
SCTP and TCP behaves in very similar ways in wireless networks. It is natural the similarity of their behaviors because both are based on the same algorithms of control congestion. However, SCTP has better performance than TCP, especially in the presence of congestion.
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
Performance Evaluation of SCTP in wireless networks
Questions
Nelson Vicuña Z.January - 2008
SCTP
Handshake
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
SCTP
Chunk Types
ID Value Chunk Type0 Payload Data (DATA)1 Initiation (INIT)2 Initiation Acknowledgement (INIT ACK)3 Selective Acknowledgement (SACK)4 Heartbeat Request (HEARTBEAT)5 Heartbeat Acknowledgement (HEARTBEAT ACK)6 Abort (ABORT)7 Shutdown (SHUTDOWN)8 Shutdown Acknowledgement (SHUTDOWN ACK)9 Operation Error (ERROR)10 State Cookie (COOKIE ECHO)11 Cookie Acknowledgement (COOKIE ACK)12 Reserved for Explicit Congestion Notification Echo (ECNE)13 Reserved for Congestion Window Reduced (CWR)14 Shutdown Complete (SHUTDOWN COMPLETE)15 to 62 reserved by IETF63 IETF-defined Chunk Extensions64 to 126 reserved by IETF127 IETF-defined Chunk Extensions128 to 190 reserved by IETF191 IETF-defined Chunk Extensions192 to 254 reserved by IETF255 IETF-defined Chunk Extensions
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
NS-2
SCTPSupports the features in the following sections of RFC 2960:
• Section 5.1 Normal Establishment of an Association (rudimentary handshake)
• Section 6.1 Transmission of DATA Chunks• Section 6.2 Acknowledgement of Reception of DATA
Chunks• Section 6.3 Management Retransmission Timer• Section 6.4 Multi-homed SCTP Endpoints• Section 6.5 Stream Identifier and Stream Sequence
Number• Section 6.6 Ordered and Unordered Delivery• Section 6.7 Report Gaps in Received DATA TSNs• Section 7.2 SCTP Slow-Start and Congestion Avoidance• Section 8.1 Endpoint Failure Detection• Section 8.2 Path Failure Detection• Section 8.3 Path Heartbeat (without upper layer control)
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
SCTP, i
Acknowledging DATA Chunks
TSN : Transmission Sequence Number
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
SCTPEndpoint A
SCTPEndpoint B
DATA chunk TSN=100
DATA chunk TSN=101
DATA chunk TSN=102
DATA chunk TSN=103
DATA chunk TSN=104
DATA chunk TSN=105
SACK chunk Cumulative TSN=108
DATA chunk TSN=106
DATA chunk TSN=107
DATA chunk TSN=108
SCTP, and ii
Performance Evaluation of SCTP in wireless networks
VICUNA, Nelson
DATA chunk TSN=112
DATA chunk TSN=113
DATA chunk TSN=117
DATA chunk TSN=119
DATA chunk TSN=120
DATA chunk TSN=116
SACK chunk Cumulative TSN=113Gap Ack Block #1 Start = +1 End = +3Gap Ack Block #2 Start = +10 End = +11
DATA chunk TSN=111
DATA chunk TSN=110
DATA chunk TSN=121
DATA chunk TSN=122
XDATA chunk TSN=123
DATA chunk TSN=124
DATA chunk TSN=125
DATA chunk TSN=126
DATA chunk TSN=114X
DATA chunk TSN=115X
DATA chunk TSN=118
Acknowledging DATA Chunks
TSN : Transmission Sequence Number