Module CT2053N: Network Devices Lecture Week 1

Agenda Module Introduction  Your Module Leader  Your Lecturer and tutors  Module Aims/Objectives  Module outcomes after successful completion  Module Assessments and Syllabus Summary  Recommended booklist Week 1 Lecture Coverage  LAN Devices.  OSI Reference Model and encapsulation techniques in each layers.  LAN technology

Module Leaders’ Roles Every module has two module leaders: Creates the main lecture/tutorial notes Writes coursework and examinations Moderates the coursework and examinations results Serves as a lecturer for that module (usually in London) Writes localised lecture/tutorial notes Marks the coursework and examinations (lecturers/tutors might also be involved in marking) Serves as a lecturer for that module

Your Lecturer Is Saroj Lamichhane Bsc Hons. (Network Engineering) The University of Northampton

Your Tutor Is… Mr. Saroj Lamichhane

Module aims The module aims:  To gain an understanding of the operational structure of a network and its components in relation to OSI layer.  To appreciate the concept of LAN and WAN design and various devices with respect to the OSI model.  To gain an in-depth understanding of routing, routing protocols and the need for appropriate configuration.  To gain experience in configuring routers and IP addresses for a given specification

Module outcomes after successful completion You will be able to: Describe the functionality of Local Area Networks (LANs) and its devices Explain the functional behaviour of each device in a network and its role in the functionality of a network. Describe TCP/IP suite of protocols and learn how to configure IP addresses

Module outcomes after successful completion… Student will be able to: Explain the flow of traffic on a LAN using the Ethernet/802.3 standards. Describe the overall purpose of Wide Area Networks (WANs). Describe when, why and how to configure a router. Identify network software management tools and their functions.

Module Assessments Assessments: 50% Exam 50% Practical Assignment Test [ individual work]  Tutorials are related to the Lectures/practical and Examinations.  Workshops are related to the Practical Assignment. Note:- Students should obtain 40% pass on aggregate from examination and coursework.

Module Syllabus Summary The OSI model and steps in data encapsulation, LAN devices and technologies, TCP/IP addressing, environment, and sub-networks. WANS and routers, Router components, CDP and basic Networking testing, troubleshooting, router boot sequence and set up mode, Router configuration modes and procedures. TCP/IP protocol suite, IP addressing and subletting, access configuration. Routing protocols and their importance, distance vector routing, link state routing. Interior and exterior routing protocols, RIP, IGRP, layers revisited.

Highly recommended Booklist Cisco Systems, Inc. (2003), Cisco Networking Academy Program CCNA 1 and 2 Companion Guide, Cisco Press ISBN Cisco Systems, Inc. (2003), Cisco Networking Academy Program CCNA 1 and 2 Lab Companion, Cisco Press ISBN

OSI reference model Seven layers open system interconnection(OSI) reference model developed by ISO. Proposed in Accepted in 1984.

OSI reference model… Why Layering?? Defines and separates networking hardware and software into distinct layers and functions Enables programmers to specialize in a particular level or layer of the networking model Provides design modularity. Encourages interoperability Allows for standardized interfaces to be produced by networking vendors

OSI reference model… Layering 7. Application layer 6. Presentation layer 5. Session layer 4.Transport layer 3.Network Layer 2.Data Link layer 1.Physical layer

OSI reference model…

Reference Models The TCP/I The TCP/IP reference model P reference model

OSI reference model… Encapsulation / Decapsulation:

OSI reference model… How encapsulation is done??

OSI reference model… How decapsulation is done??

Summary of the OSI reference Model

Network Devices Why Network Devices?? Separating or connecting or expanding the networks. Example:- repeaters, hubs, bridges, routers, switches, gateways

Network Devices Why Network Devices?? Separating or connecting or expanding the networks. Networks cannot be made larger by simply adding new computers and more cables If we do so….the networks will be less efficient Segmenting or dividing the larger LANs to form the smaller LANs and connecting them.

Network Devices… Required Components of LAN devices: Repeaters and Hubs bridges routers switches gateways

Network Devices… Repeaters and Hubs: Repeaters or hubs work at the OSI physical layer to regenerate the network’s signal and resend them to other segments Primitive hub can be viewed as a multiport repeater It regenerates data and broadcasts them to all ports

Network Devices… Limitations and features of Repeaters and Hubs: Have only one collision domain Do not isolate and filter packets Can connect different types of media The most economic way of expanding networks

Network Devices… Bridges: Has one input and one output Used to isolate network traffic and computers Has the intelligent to examine incoming packet source and destination addresses

Network Devices… Differences Between Bridges and Repeaters

Network Devices… Switches: Switches operate at the Data Link layer 2 of the OSI model Can interpret address information Switches resemble bridges and can be considered as multiport bridges having multiports, can better use limited bandwidth and prove more cost-effective than bridge

Network Devices… Switches… Switches divide a network into several isolated channels Packets sending from 1 channel will not go to another if not specify Each channel has its own capacity and need not be shared with other channels

Network Devices… Switches… 10Mbps 3.3 Mbps Hub Switch

Network Devices… Routers: Layer 2 Switches cannot take advantage of multiple paths Routers work at the OSI layer 3 (network layer) They use the “logical address” of packets and routing tables to determine the best path for data delivery

Network Devices…

Network devices… Distinguish between switch/bridge and router Bridges forward everything they don’t recognize Routers select the best path Routers are layer 3 devices which recognize network address Bridges are layer 2 devices which look at the MAC sublayer node address

Summary Repeaters are the least expensive way to expand a network, but they are limited to connecting two segments Bridges function similar to repeaters, but can understand the node addresses Switches can be considered as multiport bridges, can divide a network into some logical channels Routers interconnect networks and provide filtering functions. They can determine the best route