Download - Lecturer Slides2
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 1/33
LECTURER SLIDES
NETWORK PROTOCOLS
Department of Electrical Engineering
Faculty of Engineering
University of Hasanuddin
2009
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 2/33
OSI Reference Model
Being able to connect networks and disparate systems one
standard method. 1978 the ISO released an architecture
Revised in 1984 international standards for networked
commun ca on, ca e e e erence o e . The OSI model presents a layered approach to networking.
The OSI model :
Simplified how network hardware and software work together
Eased troubleshooting woes by providing a specific method for how
components should function.
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 3/33
OSI Reference Model
Application layer :
Provides a set of interfaces for applications to use togain access to networked services.
Presentation layer:
Converts data into a generic format for networktransmission; for incoming messages, it converts data toa format that the receiving application can understand.
Session layer:
Enables two parties to hold ongoing communications
Transport layer:
Manages the transmission of data across a network.
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 4/33
OSI Reference Model
Network layer
Handles addressing messages for delivery
Translates logical network addresses and names into
their physical counterparts.
Data Link layer:
Sends special data frames from the Network layer to
the Physical layer.
Physical layer converts :
Bits into signals for outgoing messages
Signals into bits for incoming messages.
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 5/33
OSI Reference Model
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 6/33
Application Layer (Top Layer)
Allows access to network services (networked
file transfer, message handling, anddatabase query processing)that support
.
Controls general network access, flow control,
and error recovery for applications when
appropriate.
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 7/33
Presentation Layer Manages data-format information for networked
communications
Converts outgoing messages into a generic format
Converts incoming messages from that generic formatinto one that makes sense to the receiving application
Protocol conversion, data encryption and decryption,graphics commands, compression and decompressionfunctions.
Software called a redirector operates: interceptsrequests for service and redirects requests thatcannot be resolved locally to the networked resourcethat can handle them.
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 8/33
Session Layer Hold ongoing communications, means applications on
each end of the session are able to exchange data forthe duration of the session
Manages session setup, information or message
exc anges Tear-down when the session ends
Identification only designated parties can
participate in the session Handles security services for controlling access to
session information
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 9/33
Session Layer Furnishes synchronization services between tasks at
each end of the session Places checkpoints in the data stream so if
communications fail, only data after the most recent
c ec point nee to e retransmitteManages issues such as who may transmit data at a
certain time and for how long
Maintains a connection through transmission ofmessages that keep the connection active
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 10/33
Transport Layer Manages the flow control of data between parties
across network by segmenting long streams of data intochunks adhere to the maximum packet size for thenetworking medium in use
Provides error checks to uarantee error-free data
delivery Resequences chunks back into the original data when it
is received
Provides acknowledgment of successful transmissions Responsible for requesting retransmission if some
packets do not arrive error-free
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 11/33
Network Layer Addresses messages for delivery
Translates logical network addresses and names intotheir physical equivalents
Decides how to route transmissions between computers,
how to get data from one point to the next Considers other factors, such as quality of service
information, alternative routes, and delivery priorities
Handles packet switching, data routing, and networkcongestion control
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 12/33
Data Link Layer Handles special data frames between the Network
and Physical layers. Packages raw data from the Physical layer into
data frames for deliver to the Network la er
(receiving End) A data frame is the basic unit for network traffic as
data is sent across the network medium; it is a highly
structured format in which data from upper layers isplaced for sending, and from which data from upper
layers is taken on receipt.
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 13/33
Physical Layer Converts bits into signals for outgoing messages, and
signals into bits for incoming ones Arranges the transmission of a data frame’s bits when
they are dispatched across the network
Manages the interface between a computer and thenetwork medium
Instructs the driver software and the network interface
as to what needs to be sent across the medium.
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 14/33
Standardized Network Communication
IEEE 802 specs defined how network adapters access and transmitinformation over the network cable:
802.1 Internetworking 802.2 Logical Link Control (LLC)
802.3 Carrier-Sense Multiple Access with Collision Detection (CSMA/CD) LANs(Ethernet)
.
802.5 Token Ring LAN 802.6 Metropolitan Area Network (MAN)
802.7 Broadband Technical Advisory Group
802.8 Fiber Optic Technical Advisory Group
802.9 Integrated Voice and Data Networks 802.10 Network Security
802.11 Wireless Networks
802.12 Demand Priority Access LAN, 100BaseVG-AnyLAN
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 15/33
802 Specs within OSI Model
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 16/33
Data Link Layer (802 Specs)
Logical Link Control (LLC) : For error correction and flow
control Media Access Control (MAC):
For access control The Logical Link sublayer (as defined by 802.2)
-
Defines the use of logical interface points, called Service AccessPoints (SAPs), that other computers can use to transfer information
from the LLC sublayer to the upper OSI layers.
Provides shared access for multiple NIC s with the Physical layer.
Responsible for ensuring error-free data transmission between
computers on a network Direct communication with a
computer’s NIC
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 17/33
Up & Down the Protocol Stack
A protocol suite, also called a stack, is a
combination of protocols that work together toachieve network communication.
Three sections that ma to the OSI model:
Network
Transport
Application
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 18/33
Network Protocol
Provide the following services:
Addressing and routing information Error checking
Re uestin retransmissions
Establishing rules for communicating in a particularnetworking environment called link services
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 19/33
Network Protocol
Samples popular Network Protocols:
DDP (Delivery Datagram Protocol) Apple’s datatransport protocol that is used in AppleTalk
IP (Internet Protocol) Part of the TCP/IP protocol suite
IPX (Internetwork Packet Exchange) and NWLinkNovell’s NetWare protocol (and Microsoft’simplementation of this protocol, respectively) used for
packet routing and forwarding NetBEUI Developed by IBM and Microsoft, it provides
transport services for NetBIOS
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 20/33
Transport Protocol
Responsible for ensuring reliable data deliverybetween computers
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 21/33
Transport Protocol
Samples popular Transport Protocols: ATP (AppleTalk Transaction Protocol) and NBP (Name
Binding Protocol) AppleTalk’s session and data transportprotocols
NetBIOS/NetBEUI NetBIOS establishes and manages;
transport services for that communication SPX (Sequenced Packet Exchange) and NWLink Novell’s
connection- oriented protocol that is used to guarantee datadelivery (and Microsoft’s implementation of this protocol)
TCP (Transmission Control Protocol) The portion of theTCP/IP protocol suite that is responsible for reliable deliveryof data
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 22/33
Application Protocol
Responsible for application-to-application services.
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 23/33
Application Protocol
Samples popular Application Protocols: AFP (AppleTalk File Protocol) Apple’s remote file
management protocol FTP (File Transfer Protocol) Another member of the TCP/IP
protocol suite that is used to provide file transfer services
NCP (NetWare Core Protocol) Novell’s client shells andredirectors
SMTP (Simple Mail Transport Protocol) A member of theTCP/IP protocol suite that is responsible for transferringemail
SNMP (Simple Network Management Protocol) A TCP/IPprotocol that is used to manage and monitor networkdevices
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 24/33
Protocol
Something that must be met on a protocol to beused for any type of communication to take place.
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 25/33
Protocol
Some common protocol used today:
NetBEUI TCP/IP
A leTalk
APPC
X.25
HDLC
XNS
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 26/33
Protocol
NetBEUI
A simple network layer transport protocol
Developed to support NetBIOS networks.
Like NetBIOS, NetBEUI is not routable, so it really has no place on anenterprise network.
NetBEUI is the fastest transport protocol available to NT. It’s great for fast transmission, but is not usable across routed
networks.
Benefits of NetBEUI include: speed, good error protection, ease of
implementation, and low memory overhead. Some disadvantages are: not routable, very little support for cross-
platform applications, and very few troubleshooting tools available.
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 27/33
Protocol
TCP/IP
The most widely used protocol suite TCP/IP is able to span wide areas and is very flexible.
Provides cross-platform support & routing capabilities
Support for the Simple Network Management Protocol(SNMP), the Dynamic Host Configuration Protocol(DHCP), the
Windows Internet Name Service (WINS), the Domain Name
Service (DNS), and a host of other useful protocols.
However, TCP/IP’s rich set of features are provided at theexpense of additional overhead, which may make it too
cumbersome for some networks or applications.
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 28/33
Protocol
AppleTalk
Used for communication with Macintosh computers. By enabling AppleTalk, will allow Mac clients to store
and access files located on an NT Server, print to NT
printers, and vice versa. An item of note: Must first install the NT Services For
Macintosh before you can install AppleTalk.
Mac support is only available from an NTFS partition.
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 29/33
Protocol
APPC
The Advanced Program-to-Program Communication(APPC) protocol
Developed by IBM
A peer-to-peer protocol used in IBM’s Systems NetworkArchitecture (SNA) for use on AS/400-series computers.
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 30/33
Protocol
X.25
A set of wide-area protocols that are used in packet-switching networks.
Created to connect remote terminals to mainframes.
Many other wide-area communications types areavailable in the United States, X.25 is still widely used
in Europe.
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 31/33
Protocol
High-level Data Link Control (HDLC)
A flexible, bit-oriented data link protocol that is basedon IBM’s Synchronous Data Link Control (SDLC).
Has been standardized by the ISO
Support half- or full-duplex transmission, circuit- orpacket-switched networks, peer-to-peer or client/server
network topologies and transmission over cable or
wireless media.
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 32/33
Protocol
The Xerox Network System (XNS)
Created by Xerox for use in Ethernet networks Basis for Novell’s IPX/SPX, but it is seldom found in
today’s networks.
8/9/2019 Lecturer Slides2
http://slidepdf.com/reader/full/lecturer-slides2 33/33
n o e