communications (networking) presented by : john simon benneth nwogu
TRANSCRIPT
![Page 1: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/1.jpg)
Communications(Networking)
Presented by :
John Simon
Benneth Nwogu
![Page 2: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/2.jpg)
Transmission Medium
Copper Wire
Glass Fiber
Radio
Satellites
![Page 3: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/3.jpg)
RS-232
Popular standard used for asynchronous, serial communication over short distances between a computer and a modem or ASCII terminal
Precedes each character with a start bit, follows each character with an idle period at least one bit long (stop bit), and sends each bit in exactly the same length of time.
![Page 4: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/4.jpg)
Digital Signal
![Page 5: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/5.jpg)
Baud – number of changes in the signal per second that a transmission hardware generates
Bandwidth – maximum rate that a transmission system can change a signal. Measured in cycles per second (Hz)
![Page 6: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/6.jpg)
Carrier Wave
![Page 7: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/7.jpg)
Modulation Techniques
Amplitude Modulation – varies the strength of the outgoing signal in proportion to the info. being sent.
Frequency Modulation – varies the frequency of the underlying carrier in proportion to the info. being sent.
Phase Shift Modulation- changes the timing of the carrier wave abruptly to encode data.
![Page 8: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/8.jpg)
Modem
Hardware circuit that accepts a sequence of data bits and applies modulation for the sender and demodulation for the receiver.
![Page 9: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/9.jpg)
Packet
A small, self contained parcel of data sent across a computer network. Each packet contains a header that identifies the sender and the recipient, and a payload area that contains the data being sent.
Each packet is organized to the specifications of an Ethernet frame.
![Page 10: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/10.jpg)
Ethernet Frame
The basic form of a packet that the underlying hardware sends and receive across a shared medium.
![Page 11: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/11.jpg)
Transmission Error
When packets on a carrier are lost or damaged due to any interference affecting data.
Error Checkinga.Parity Checkb.Checksumc. CRC
![Page 12: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/12.jpg)
Synchronization (cont.)
Token Ring Passing- Computers attached to a token ring network
use a special, short message called token to coordinate use of the ring. One token exists on the ring at any time . To send data, a computer must wait for the token to arrive, transmit exactly one frame, and then transmit the token to the next computer. When the computers have no data to send, the token cycles around the ring at high speeds.
![Page 13: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/13.jpg)
Synchronization
Carrier Sense On Multi-Access Networks and Collision Detection (CSMA/CD)
- a mechanism used to coordinate transmission in an Ethernet network. A computer waits for an idle shared medium before it transmits data. In case of collision, the computers involved will use exponential back-off to choose which computer proceeds. Each computer delays a random time before trying to transmit again , and then doubles the delay for each successive collision.
![Page 14: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/14.jpg)
3 Different Network Technology Categories
Local Area Network Metropolitan Area Network Wide Area Network
![Page 15: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/15.jpg)
Local Area Network
Can span a single building or campus Consists of a single shared medium, usually
a cable, to which many computers attach 3 basic Topologies
a. Star Topology
b. Ring Topology
c. Bus Topology
![Page 16: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/16.jpg)
Bus Topology
![Page 17: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/17.jpg)
Bus Topology (cont.)
Uses a single coaxial cable called a backbone.
Inexpensive for modest-sized Ethernet networks.
While easy to install and add computers, heavy traffic will slow it down and a cable break will shut down the entire network.
![Page 18: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/18.jpg)
Ring Topology
![Page 19: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/19.jpg)
Ring Topology (cont.)
Using token passing, computers are connected to each other in a circle
Although good for high speed networks, it is difficult to expand, and the entire network is vulnerable if one node goes down.
It requires more cabling than a bus, and adding nodes disrupts the entire network.
![Page 20: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/20.jpg)
Star Topology
![Page 21: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/21.jpg)
Star Topology (cont.)
Each computer connects to a central hub with its own cable making it easy to add computers and more reliable than a bus.
It is more expensive than a bus because of more cable requirements.
If the central hub fails, so does the network.
![Page 22: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/22.jpg)
Wide Area Network
A network that can span sites in multiple cities, countries or continents.
WAN Technologies
- ATM
- ISDN
- SMD
![Page 23: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/23.jpg)
Two Service Paradigms
Connection Oriented service
- analogous to telephone communications in which a connection must be established between two computers before any data can be transferred
![Page 24: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/24.jpg)
Connectionless Service
- analogous to a postal mail system. Whenever it has to send data, a computer must place the data in the appropriate frame format, attach the address of the computer to which the data should be delivered and then pass the frame to the network for delivery.
![Page 25: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/25.jpg)
Service Paradigms (cont.)
![Page 26: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/26.jpg)
Network Performance Characteristics
Delay
- specifies how long it takes for a bit of data to travel across the network from one computer to another.
Throughput
- measure of the rate at which data can be sent through the network. Usually specified in bits per second(bps).
![Page 27: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/27.jpg)
Delay-Throughput Product
T x D The product of delay and throughput
measures the volume of data that can be present on the network.
A network with throughput T and delay D has a total of T x D bits in transit at any time.
![Page 28: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/28.jpg)
Different Network Equipment
Hubs Switches Routers Bridges Gateway
![Page 29: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/29.jpg)
HUBS
A device that connects multiple Computers to a network.
receives a packet (chunk) of data (a frame in Ethernet lingo) at one of its ports from a PC on the network, it transmits (repeats) the packet to all of its ports and, thus, to all of the other PCs on the network.
![Page 30: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/30.jpg)
Switches
A device that connects multiple Computers to a network.
divides the network into multiple segments, acts as a high-speed, selective bridge between the segments, and supports simultaneous connections of multiple pairs of computers which don't compete with other pairs of computers for network bandwidth.
![Page 31: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/31.jpg)
Routers
is a physical device that joins multiple networks together. Technically, a router is a "layer 3 gateway," meaning that it connects networks (as gateways do), and that it operates at the network layer of the OSI model.
![Page 32: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/32.jpg)
Bridges (Smart Repeaters)
An electronic device that used to extend a LAN.
Connects two cable segments, forwards complete, correct frames from one segment to another.
Does not forward interference
![Page 33: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/33.jpg)
Gateways
can operate at any level of the OSI model from application protocols to low-level signaling.
Acts as an intermediary between domains.
![Page 34: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/34.jpg)
ISO/OSI Layer
![Page 35: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/35.jpg)
Layer Description
Layer 1: Physical Layer deals with the basic network hardware e.g.. Fiber, twisted-
pair copper, coax Layer 2: Data Link layer
specifies how to organize data into frames and to transmit the frames e.g.. CSMA/CD, token passing, checksum, CRC
Layer 3: Network layer protocols specify how address are assigned
and how packets are forwarded from one end of the network to the other end (e.g.. IP, ARP, RARP)
![Page 36: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/36.jpg)
ISO Layer (cont.)
Layer 4:Transport layer protocols specify how to reliably transfer data from
one end to the other (e.g.. TCP, UDP, RIP) Layer 5: Session layer protocols specify how to establish a communication session
with a remote computer (e.g.. Password authentication, RPC)
![Page 37: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/37.jpg)
ISO Layer (cont.)
Layer 6: Presentation layer protocols specify how to represent data. Needed
because different computers may represent data differently (e.g. XDR).
Layer 7: Application layer protocols e.g. Lpr, rcp, rlogin,rsh, ftp, telnet,
smtp, DNS, NFS, NIS, SNMP, bootp, ntp,tftp
![Page 38: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/38.jpg)
Network Protocol Headers
![Page 39: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/39.jpg)
Frame Transmission with ISO frames protocols
![Page 40: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/40.jpg)
TCP/IP Layer
![Page 41: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/41.jpg)
TCP/IP Layer (cont.)
Application Layer
Defines TCP/IP application protocols and how host programs interface with transport layer services to use the network
Protocols:
HTTP, Telnet, FTP, TFTP, SNMP, DNS, SMTP, X Windows, other application protocols
![Page 42: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/42.jpg)
TCP/IP Layer (cont.)
Transport LayerProvides communication
session management between host computers. Defines the level of service and status of the connection used when transporting data. Protocols: TCP, UDP, RTP
![Page 43: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/43.jpg)
TCP/IP Layer (cont.)
Internet LayerPackages data into IP datagrams, which contain source and destination address information that is used to forward the datagrams between hosts and across networks. Performs routing of IP data grams.
Protocols:
IP, ICMP, ARP, RARP
![Page 44: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/44.jpg)
TCP/IP Layer (cont.)
Network Interface LayerSpecifies details of how data is physically sent through the network, including how bits are electrically signaled by hardware devices that interface directly with a network medium, such as coaxial cable, optical fiber, or twisted-pair copper wire.
Protocols:Ethernet, Token Ring, FDDI, X.25, Frame Relay, RS-232, v.35
![Page 45: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/45.jpg)
IP Addresses
32 bit IP address is divided into two parts: suffix and prefix.
The address prefix identifies the physical network to which the computer is attached
The address suffix identifies the individual computer on that network.
![Page 46: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/46.jpg)
IP Address Classes
![Page 47: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/47.jpg)
Special IP address
![Page 48: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/48.jpg)
ARP Messages
![Page 49: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/49.jpg)
IP Datagram
The internet protocol defines an IP datagram to be the basic unit of transfer across a TCP/IP internet
![Page 50: Communications (Networking) Presented by : John Simon Benneth Nwogu](https://reader036.vdocument.in/reader036/viewer/2022062516/56649da35503460f94a90355/html5/thumbnails/50.jpg)
Sources
ONLINE SOURCES:
• http://www.usyd.edu.au/is/comms/networkcourse/
• http://wks.uts.ohio-state.edu/sysadm_course/html/sysadm-326.html
• http://margo.student.utwente.nl/simon/finished/thesis/thesis2/node11.html
• http://www.pku.edu.cn/academic/research/computer-center/tc/html/TC0102.html
• http://www.netbook.cs.purdue.edu/subjindx/indx420.htm
TEXTBOOK SOURCES:
• Computer Networks and Internets with Internet Applications 3rd Edition by Douglas E. Comer