Group Presentation
Group 1
Internet and its Protocols
Shanghai Jiao Tong University
School of Electronic Information and Electrical Engineering
2015
Group 1 Members:
Students:
Niklas Lensing
(Introduction and History of Internet)
Mi ZaoYu
(Introduction and History of Internet)
Sampa Nkonde
(TCP/IP, OSI, Presenter)
Hanif Khushk
(TCP/IP and OSI comparison)
Ahmed Mikaeil
(Data exchange example)
Bilal Korir
(Security, Moderator)
Mohammed Abdullah (IoTs protocols)
Lecturer: Professor Yanmin Zhu
2
Presentation Outline
• Introduction and History of Internet
• Internet Protocols
- Open System Interconnection model (OSI)
- Transport Control Protocol/Internet Protocol (TCP/IP)
- Comparative analysis between OSI/TCP/IP
• Internet Security
• Internet Protocols related to IoTs
• Conclusion
• Q&A
3
Introduction
The Internet in a nutshell
• A worldwide network of connected networks
• A data network allows nodes to exchange information with each other
Mobile network
Global ISP
Home network
access
points
wired
links
Regional ISP
Institutional network
router
4
Introduction
The Internet – A revolution
• Invention of the Internet is sometimes said to be comparable to the invention of
printing books
• Changed the way we live our lifes
 Communication, Access to information, Day to Day Life, etc
• Helpes to the development of completely new economic branches
5
Introduction
Brief historic overview
• Early phase (1960s to 1970s)
– Military use: Advanced Research Projects Agency Network (ARPANET)
– Basic idea: develop a network infrastructure without a single point of failure
• Wild Phase (1970s to 1990s)
– Change from military to academic use
– Mostly used for research and exchange of information
• Commercialization (from 1990s)
– Shutdown of ARPANET
– Expansion of the Internet over the whole world
6
INTRODUCTION
Recent trends in the Internet
• Web 2.0
– User generated content (Facebook, Twitter, Youtube …)
• Cloud Computing
– Make your data accessible from everywhere!
• Internet of Things
– Enable “Things“ to communicate with each other
– Connect “Things“ to the Internet
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PROTOCOLS
• Cooperative action is necessary
– computer networking is not only to exchange bytes
– huge system with several utilities and functions. For examples
• error detection
• Encryption
• Routing
• etc.
• For proper communication, entities in different systems must speak
the same language
– there must be mutually acceptable conventions and rules about the content, timing and
underlying mechanisms
• Those conventions and associated rules are referred as
“PROTOCOLS”
8
Simplified File Transfer Architecture
File Transfer Application Layer: Application specific commands, passwords
and the actual file(s) – high level data.
Communications Service Module: Reliable transfer of those data – error
detection, ordered delivery of data packets, etc.
Network Module: Actual transfer of data and dealing with the network – if the
network changes, only this module is affected, not the whole system.
9
A General Three Layer Model
• Generalize the previous example for a generic application
– we can have different applications (e-mail, file transfer, …)
• Network Access Layer
• Transport Layer
• Application Layer
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OSI Reference Model
• Open Systems Interconnection
• Reference model
– provides a general framework for standardization
– defines a set of layers and services provided by each layer
– one or more protocols can be developed for each layer
• Developed by the International Organization for Standardization
(ISO)
– also published by ITU-T (International Telecommunications Union)
11
OSI Reference Model
• "Please Do Not Tell Secret Passwords Anytime"
• "Please Do Not Throw Salami Pizza Away"
• — Shh! bottom-to-top phrase.
12
OSI Layers (1) - Physical
• Physical
– Physical interface between devices
– Characteristics
• Mechanical - interface specs
• Electrical - voltage levels for bits, transmission rate
13
OSI Layers (2) – Data Link
• Data Link - Basic services: error detection and control, flow control at the link
level (p to p)
• Higher layers may assume error free transmission
– Later a sublayer is added to Data Link Layer
• MAC (Medium Access Control) sublayer to deal with broadcast
networks
• (MAC) protocol is used to provide the data link layer
• The MAC protocol encapsulates a (payload data) by adding a 14 byte header
(Protocol Control Information (PCI)) before the data and appending an
integrity checksum
• The checksum is a 4-byte (32-bit) Cyclic Redundancy Check (CRC) after the
data.
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OSI Layers (3) - Network
• Network
– This layer provides switching and routing technologies, creating
logical paths, known as virtual circuits, for transmitting data
from node to node.
– Routing and forwarding are functions of this layer, as well as
addressing, internetworking, error handling, congestion
control, QoS (Quality of Service) and packet sequencing.
– Several other internetworking issues
• e.g. differences in addressing, max. data length, etc.
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OSI Layers (3) – Network con’t
• Typical protocols:
• IP – Internet Protocol i.e IPv4 or IPv6
• Provide packet delivery
• ICMP – Internet Control Message Protocol
• Define the procedures of error message transfer
16
OSI Layers (4) - Transport
• Transport
– This layer provides transparent transfer of data between end
systems, or hosts, and is responsible for end-to-end error recovery
and flow control.
– End to end exchange of data
– In sequence, no losses, no duplicates
– If needed, upper layer data are split into smaller units
– Transport Protocols examples - TCP, SPX and UDP
17
OSI Layers (5) - Session
• Session
– Control of dialogues
• whose turn to talk?
• Dialogue discipline (full-duplex, half-duplex)
– This layer establishes, manages and terminates connections
between applications.
– The session layer sets up, coordinates, and terminates
conversations, exchanges, and dialogues between the applications
at each end.
– It deals with session and connection coordination.
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OSI Layers (6) - Presentation
– This layer provides independence from differences in data representation
(e.g., encryption) by translating from application to network format, and
vice versa.
– This layer formats and encrypts data to be sent across a network, providing
freedom from compatibility problems.
– It is sometimes called the syntax layer.
– Typical Protocols examples - SSL, WEP, WPA, etc.
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OSI Layers (7) - Application
• Application layer protocols define the rules when implementing
specific network applications
• Rely on the underlying layers to provide accurate and efficient data
delivery
• Typical Protocols:
• FTP – File Transfer Protocol
• For file transfer
• DNS – Domain Name System
• Translates domain names into IP addresses.
• SMTP – Simple Mail Transfer Protocol
• For mail transfer
• HTTP – Hypertext Transfer Protocol
• For Web browsing
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TCP/IP Protocol Suite
• Most widely used interoperable network protocol
architecture
• Specified and extensively used before OSI
– OSI was slow to take place in the market
• Funded by the US Defense Advanced Research Project
Agency (DARPA) for its packet switched network
(ARPANET)
– DoD automatically created an enormous market for TCP/IP
• Used by the Internet
21
What is TCP/IP?
• TCP/IP is a set of protocols developed to allow cooperating computers to share
resources across a network
• TCP stands for “Transmission Control Protocol”
• IP stands for “Internet Protocol”
• They are Transport layer and Network layer protocols respectively of the protocol
suite
• The most well known network that adopted TCP/IP is Internet – the biggest WAN
in the world
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TCP/IP Protocol Suite
• TCP/IP does not have an official layer structure
• But protocols imply one
–
–
–
–
–
Application layer
Transport (host to host) layer
Internet layer
Network access layer
Physical layer
• Actually TCP/IP reference model has been built on its protocols
– That is why that reference model is only for TCP/IP protocol suite
– and this is why it is not so important to assign roles to each layer in TCP/IP; understanding TCP,
IP and the application protocols would be enough
23
Network Access and Physical Layers
• TCP/IP reference model does not discuss these layers
too much
– the node should connect to the network with a protocol
such that it can send IP packets
– this protocol is not defined by TCP/IP
– mostly in hardware
– a well known example is Ethernet
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Internet Layer
• Connectionless, point to point internetworking protocol
(uses the datagram approach)
– takes care of routing across multiple networks
– each packet travels in the network independently of each other
• they may not arrive (if there is a problem in the network)
• they may arrive out of order
– a design decision enforced to make the system more flexible and
responsive to loss of some subnet devices
• Implemented in end systems and routers as the Internet
Protocol (IP)
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Transport Layer
• End-to-end data transfer
• Transmission Control Protocol (TCP)
– connection oriented
– reliable delivery of data
– ordering of delivery
• User Datagram Protocol (UDP)
– connectionless service
– delivery is not guaranteed
• Can you give example applications that use TCP and UDP?
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Application Layer
• Support for user applications
• A separate module for each different application
– e.g. HTTP, SMTP, telnet
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OSI vs. TCP/IP
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OSI vs. TCP/IP con’t
• There are two basic types of networking models:
– Protocol models
• Provides a model that closely matches the structure of a particular protocol
suite.
– Reference models
• Provides a common reference for maintaining consistency within all types of
network protocols and services.
– TCP/IP model is a network protocol model
• Because it describes the functions that occur at each layer of protocols
within the TCP/IP suite.
– OSI mode is a network reference model.
• It is used for network design, operation specifications, and troubleshooting.
29
But
how does the Internet actually
work?
30
Communicating Over the Network
• A networking model (OSI or TCP/IP) is only a representations
of network operation . The model is not the actual network.
• However TCP/IP model describes the protocols implemented
on both the sending and receiving hosts, that interact to
provide end-to-end delivery of applications over a network.
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Data Exchange Example
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INTERNET SECURITY
Internet Security - History
•
1960, the term “Hacker” was introduced in MIT
•
1973, invention of TCP/IP protocol without security constrains
•
1983, the 414s group broke into top-secret systems
•
•
•
1986, Morris worm, first worm distributed over the Internet
1988, Kevin Mitnick, accessed unauthorized network and stole intellectual
properties. Caused $ 80 million damage
2000, ILOVEYOU worm, caused about 5.5~8.7 billon $ damage worldwide
What’s the Problem?
•
•
Information over the Internet is Free, Available,
Unencrypted, and Untrusted.
Not desirable for many Applications
•
•
•
•
•
•
•
Electronic Commerce
Software Products
Financial Services
Corporate Data
Healthcare
Subscriptions
Legal Information
Internet Security – Attack Methods
Eavesdropping
Interception of communications.
Internet Security – Attack Methods
•
Viruses
Once a file is opened, the virus will be
activated within the system.
• Almost all viruses are attached to an executable
file, which means the virus may exist on your
computer but it actually cannot infect your
computer unless you run or open the malicious
program.
Internet Security – Attack Methods
Worm
Self‐replicating, propagate through emailing list, and connected
computers in the same network.
Internet Security – Attack Methods
Trojan
Looks like normal programs, but it is not. Usually Carries a virus.
Internet Security – Attack Methods
Phishing
Trick users into writing private information on a fake website that looks
like the original one.
Internet Security – Attack Methods
Spoofing
Hide the real identity by using different IP address
Internet Security – Attack Methods
Denial of Service
Send too many requests to a system, eventually the system cannot respond to
any request any more.
Internet Security – Protection Methods
•
Cryptography: use of codes and ciphers to transform information into unintelligible data
•
Antivirus: used to detect them and cure an infected system.
•
Firewall: border control mechanism
•
Intrusion Detection Systems: can be software and hardware devices used to detect an
attack
•
Security Protocols: suite of protocols, create a secure channel between a sender and
receiver (Examples: SSL, IPsec,etc.)
Transition!
From connected computers
to
connected things
Introduction to IoTs
• IoT: Internet Of Things
– Connect all devices, systems and services
– IoT is coming to user’s daily life
– Huge amount of IP addresses is needed
MI smart bulb
MI smart switch
MI smart camera
45
MI smart band
IoT in 2010
IoT in 2015
EXAMPLES OF IoT PROTOCOLS
MQTT: Message Queue Telemetry Transport
• Used for Collecting Device Data。
• Released by IBM and targets lightweight M2M
communications。
• An asynchronous publish/subscribe protocol that runs
on top of the TCP stack.
• In MQTT there is a broker (server) that contains topics.
5
MQTT: Message Queue Telemetry Transport cont’d
6LoWPAN :IPv6 over Low power Wireless Personal Area Networks
• Formulated by devices that are compatible with the IEEE 802.15.4
standard.
• 6LowPAN uses an adaptation layer between the network (IPv6) and
data link layer (IEEE802.15.4 MAC) to fragment and reassemble IPv6
packets.
• 6LoWPAN provides a WSN node with IP communication capabilities
by putting an adaptation layer above the IEEE 802.15.4 link layer for
the packet fragmentation and reassembly purpose
5
ZIGBEE
• ZigBee is a technological standard designed for control and
sensor networks
• Based on the IEEE 802.15.4 Standard
• Created by the ZigBee Alliance
• Operates in Personal Area Networks (PAN’s) and device-todevice networks
• Connectivity between small packet devices
• Control of lights, switches, thermostats, appliances, etc.
ZIGBEE Characteristics
•
•
•
•
•
•
•
Low cost
Low power consumption
Low data rate
Relatively short transmission range
Scalability
Reliability
Flexible protocol design suitable for many
applications
ZIGBEE Applications
monitors
sensors
automation
control
monitors
diagnostics
sensors
INDUSTRIAL
&
COMMERCIAL
CONSUMER
ELECTRONIC
S
TV VCR
DVD/CD
Remote
control
ZigBee
PERSONAL
HEALTH
CARE
consoles
portables
educational
LOW DATA-RATE
RADIO DEVICES
TOYS &
GAMES
HOME
AUTOMATION
PC &
PERIPHERAL
S
security
HVAC
lighting
closures
mouse
keyboard
joystick
XMPP: Extensible Messaging and
Presence Protocol

The base protocol used for XMPP is RFC 2779 (Instant Messaging /Presence
Protocol Requirements).

There are 2 drafts namely XMPP Core and XMPP Instant Messaging
currently on XMPP.
Presence and Instant Messaging
• Presence – Presence is a means for finding, retrieving, and subscribing to
changes in the presence information (e.g. "online" or "offline") of other users.
• Instant Messaging – It is a means for sending small, simple messages that
are delivered immediately to online users.
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XMPP: Extensible Messaging and Presence Protocol
• Designed for chatting and message exchanging.
• Standardized by the IETF.
• Lately XMPP has re-gained a lot of attention as a communication protocol suitable
for the IoT.
• XMPP runs over TCP and provides publish/subscribe (asynchronous) and also
request/ response (synchronous) messaging systems.
• Designed for near real-time communications and thus, it supports small message
footprint and low latency message exchange.
• XMPP has TLS/SSL security built in the core of the specification
8
China Mobile released I0T open platform OneNet
Conclusion
The internet has changed the face of
communications, commerce, and indeed
the world and over time the internet itself
has changed too.
Xie`xie
Q&A