UPPER LAYER SWITCHING

Size: px
Start display at page:

Download "UPPER LAYER SWITCHING"

Transcription

1 DATA COMMUNICATIONS MANAGEMENT UPPER LAYER SWITCHING Gilbert Held INSIDE Upper Layer Operations; Address Translation; Layer 3 Switching; Layer 4 Switching OVERVIEW The first series of LAN switches to reach the market operated at Layer 2 of the ISO Reference Model. In doing, so they represented a multi-port bridge because they would forward, filter, or flood frames based on the destination MAC address in each frame. Exhibit 1 illustrates a symmetrical 4-by-4 or 16-port LAN switch. As frames reach the switch from either directly connected workstations, servers, or shared media hubs, the switch first checks the destination address of the frame. In doing so, the switch searches its port-address table. The port-address table represents a linear table of MAC addresses associated with each port that the switch learns by noting the source address in each frame. The first time the switch is powered on, its port-address table is empty. Thus, the first frame that arrives at the switch cannot have a match occur between the destination address in the frame and the switch s port-address table. This means the switch will record the source address of the frame in its port-address table and associate that address with the port where the frame entered the switch, flooding the frame onto all ports other than the port where the frame entered the switch. Thus, the switch initially is not too efficient; however, as entries build up into its port-address table, it gains efficiency. For example, the 16-port switch shown in Exhibit 1 has the capability PAYOFF IDEA Over the past decade, LAN switches grew in their use in organizational networks from experimental devices to the point where they have replaced the use of a majority of conventional hubs. At the same time, LAN switches made a significant penetration of organizational networks, and numerous features were added to different vendor products. One of those features that significantly alters the performance capability of a LAN switch is its ability to switch at layers above the media access control (MAC) layer. By understanding how LAN switches can operate above the MAC layer, one can obtain an appreciation for how this additional capability can be used in a network. This, in turn, will enable one to consider if the extra cost of LAN switches that operate at higher layers in the International Standards Organization (ISO) Open System Interconnection (OSI) Reference Model is warranted, or if a switch that operates at a lower layer in the reference model might satisfy one s organizational requirements.

2 EXHIBIT 1 A 16-Port LAN Switch with 8 Simultaneous Cross- Connections to support a maximum of 16/2, or 8 simultaneous conversations on a frame-by-frame basis. If each port is a Fast Ethernet port operating at 100 Mbps, then the maximum throughput of the switch becomes 100 Mbps 8, or 800 Mbps. In comparison, a Fast Ethernet shared hub is limited to a maximum data transfer of 100 Mbps. UPPER LAYER OPERATIONS To obtain an appreciation for the manner in which a LAN switch can be modified to operate at higher layers in the ISO Reference Model requires a review of how higher layer protocols are transported in a LAN frame. Because there are numerous LAN and WAN protocols, the focus here is on the use of Ethernet to transport the TCP/IP protocol suite because these two protocols represent the vast majority of LAN and WAN protocols in use today. Exhibit 2 illustrates the formation of an Ethernet LAN frame to transport the TCP/IP protocol suite. In examining Exhibit 2, note that the TCP/IP protocol suite predated the effort of the International Standards Organization (ISO) in developing its Open System Interconnection Reference Model. Due to the development of the TCP/IP protocol suite prior to the OSI Reference Model, the suite used five layers, with its fifth layer representing Layers 5 through 7 (Session, Presentation, and Application) of the OSI Reference Model. As TCP/IP application data is generated, an applicable transport layer protocol is added. Although TCP and UDP are shown as the transport headers in Exhibit 2, in actuality the protocol suite supports additional transport layer protocols. However, TCP and UDP probably account for in excess of 99 percent of transport layer protocols used in the suite.

3 EXHIBIT 2 The Transport of the TCP/IP Protocol Suite by an Ethernet LAN Frame

4 At the transport layer, the destination port number in the TCP or UPD header destination identifies the application being transported. For example, TCP port 21 identifies Telnet, while port 80 identifies HyperText Transport Protocol (HTTP) Web traffic being transported by TCP. As one moves down the TCP/IP protocol suite, the IP header is added at the network layer. The IP header includes both a 32-bit destination address and a 32-bit source address field that identify the recipient and originator of the packet flowing over the WAN. At the local area network (MAC layer), packets are transported via LAN frames. In an Ethernet environment, the LAN header consists of a preamble for synchronization, destination and source MAC addresses, and a length field. The Ethernet payload field is limited to transporting a maximum of 1500 bytes, whereas an IP datagram can be up to 65 Kbytes in length. Therefore, to enable datagrams with a length exceeding 1500 bytes to be transported via an Ethernet LAN, a router is responsible for fragmenting datagrams to ensure they fit within the Ethernet payload. ADDRESS TRANSLATION At Layer 2, MAC addresses are used, with frames delivered based on the destination MAC address contained in a frame. Because IP datagrams are routed based on the destination IP address contained in the IP header, one might be puzzled as to the manner by which an IP datagram is delivered to a destination on an Ethernet network that uses MAC addresses. The answer to this is the Address Resolution Protocol (ARP). When a router receives an IP datagram for delivery onto a LAN, it needs to create a LAN frame with a MAC address that corresponds to the destination IP address in the datagram. The router will first check its cache memory to see if it previously learned the MAC address required for the delivery of the datagram. Assuming that that address was not previously learned, the router will broadcast an ARP frame onto the LAN. This frame will contain the destination IP address of the datagram that is known and set the field of the MAC addresses to all zeroes because that value is not known. The LAN station that has the IP address in the ARP frame will copy that frame off the LAN, insert its MAC address into the frame, and direct the frame back to the router. The ARP response informs the router of the MAC address it needs to use to create a frame to deliver the IP datagram. While this method of address resolution is relatively efficient, when the ARP frame is broadcast and a response flows back to the issuing device, other traffic is precluded from flowing on the network. Thus, a large number of address resolution operations can adversely affect the throughput obtainable on the LAN. Now that one has an appreciation for the manner by which IP datagrams are transported via Ethernet frames and the address translation process, one can focus on how upper layer switching occurs, how different types of upper layer

5 switches can be used, and the advantages and disadvantages associated with different higher layer switching methods. LAYER 3 SWITCHING The first method of upper layer switching to be incorporated into LAN switches is what is referred to as Layer 3 switching. A Layer 3 switch looks further into each Ethernet frame (see Exhibit 2) to determine the destination IP address being transported. The switch then uses the IP address as a mechanism for the delivery of frames. The key advantage associated with a Layer 3 switch is the fact that it can be configured to route frames based on network segment addressing. For example, if the organization has the Class C IP network address of , one might have previously subnetted the network into a number of subnets. If one used eight subnets, one would then reduce the host address portion of the last byte of the network address to 5 bits because 3 bits would be used for the subnet. Using 5 bits for each subnet would enable a maximum of 2 5 2, or 30, devices per subnet because a subnet address of all zeroes and a subnet address of all ones cannot be used. This means one could place a group of up to 30 devices on a conventional hub and connect each hub to one of eight switch ports to enable the switch to route traffic to their applicable destination. Because a Layer 3 switch looks inside each frame to determine the IP address, this eliminates the necessity to perform ARP. In addition, broadcasts are normally restricted to each segment, which further enhances the efficiency of the Layer 3 switch. While the use of a Layer 3 switch can reduce broadcasts and eliminate ARP, its level of overall switching performance is less than that of a Layer 2 switch. This is because a Layer 3 switch must look further into each frame to make its switching decisions based on the destination IP address transported within a frame. In addition, because some IP datagrams can be transported by multiple frames, the Layer 3 switch must keep track of this fact and know that subsequent frames without the IP header are part of a flow and must be routed to the same destination. Needless to say, this adds to the complexity of the software used to perform Layer 3 switching as well as its throughput capability. Another disadvantage associated with a Layer 3 switch is the fact that it is not self-learning. This means one must take the time to configure the switch, with the amount of time required to do so based on the number of ports on the switch and the ease of using its configuration screen setup facility. Although the additional software required to perform switching at the network layer initially resulted in a high premium for Layer 3 switching, today this capability can be included in some Layer 2/3 LAN switches without any additional cost. What the network manager and LAN admin-

6 istrator must consider is if the lower rate of frame processing, typically expressed in frames per second for frame lengths of 128, 256, 512, and 1526 bytes, is sufficient to support the application. Unless the organization is transporting real-time voice where any additional delay can be critical to the capability to reconstruct digitized voice, the additional delay associated with the use of Layer 3 switching is essentially transparent to FTP and Web traffic. Two examples of popular Layer 3 switches are the 3Com Switch 4005 and the Cisco Systems Catalyst The 3Com Switch 4005 represents a low-cost, high-performance modular switch in a 14-slot chassis. The switch can be configured to support up to 24 Gigabit Ethernet or 96 Fast Ethernet ports and supports IP routing at Layer 3 of the OSI Reference Model. The Cisco 4000 provides a similar capability by supporting 24 Gigabit Ethernet or 96 Fast Ethernet connections. Both vendors also manufacture numerous additional Layer 3 switches that extend the support of IP switching to ATM, Token Ring, and even FDDI transports by looking into the Layer 2 frames to make Layer 3 switching decisions. LAYER 4 SWITCHING One of the limitations associated with Layer 3 switching is the fact that it does not include the capability to recognize applications and act upon the application being transported. Layer 4 switching solves this limitation by looking further into the frame so that it reads the transport header, such as the TCP header or the UDP header. As previously noted, the TCP and UDP headers include a destination port field, the value of which identifies the application being transported. By reading further into the LAN frame, a Layer 4 switch obtains the ability to be configured to route or switch frames based on the application being transported. For example, a Layer 4 switch could be configured to route all FTP traffic to one port, all Telnet traffic to a second port, all Web traffic to a third port, etc. By itself, a Layer 4 switch is not too practical. However, additional software in the form of load balancing has resulted in Layer 4 switches being referred to as an application layer switch that performs certain functions to include load balancing. Because a Layer 4 switch looks further into a LAN frame, its frame processing rate is a bit slower (no pun intended) than a Layer 3 switch. In addition, similar to a Layer 3 switch, a Layer 4 switch must be configured. However, the biggest disadvantage of a Layer 4 switch is the fact that for many organizations its use is not practical. The reason for a Layer 4 switch being impractical for many organizations results from the fact that many organizations commonly run multiple FTP and Web servers and until recently were forced to purchase expensive load balancing hardware that would route frames based on both the contents of the destination port in the TCP or UDP header, previously routed traffic, and the

7 total number of configured servers. Because many organizations that maintained multiple servers and a load balancer also used LAN switches, the addition of load balancing to a Layer 4 LAN switch represented a natural evolution of LAN switching. Such switches are now commonly referred to as application layer switches, of which load balancing represents one of several popular applications. Other applications included in certain Layer 4 LAN switches include authentication, authorization, and accounting (AAA), which were previously performed by a separate server connected to a LAN. RECOMMENDED COURSE OF ACTION Similar to any hardware product, the selection of an applicable LAN switch should be based on an organization s requirements. If the organization needs to transport time-critical frames, one will probably want to use a Layer 2 switch. If the organization needs to move frames directly onto different networks, one will probably want to consider a Layer 3 switch. If the organization requires the routing of traffic based on the application being transported, a Layer 4 switch should be considered. However, as noted earlier in this article, one may wish to support a specific application within a Layer 4 switch, such as load balancing. In this event, the use of an application layer LAN switch should be considered. By matching organizational requirements against the capabilities of different types of LAN switches, the selection process will result in a device best suited to satisfy organizational requirements. Gilbert Held is an award-winning lecturer and author. Gil is the author of over 40 books and 400 technical articles. Some of Gil s published titles include High Speed LAN Switching, published by John Wiley & Sons, and Internetworking Voice and Data Networks, 3rd edition, published by Osborne McGraw-Hill. Gil can be reached via at

51-30-60 DATA COMMUNICATIONS MANAGEMENT. Gilbert Held INSIDE

51-30-60 DATA COMMUNICATIONS MANAGEMENT. Gilbert Held INSIDE 51-30-60 DATA COMMUNICATIONS MANAGEMENT PROTECTING A NETWORK FROM SPOOFING AND DENIAL OF SERVICE ATTACKS Gilbert Held INSIDE Spoofing; Spoofing Methods; Blocking Spoofed Addresses; Anti-spoofing Statements;

More information

Lecture 17 Overview. Last Lecture. Wide Area Networking (2) This Lecture. Internet Protocol (1) Source: chapters 2.2, 2.3,18.4, 19.1, 9.

Lecture 17 Overview. Last Lecture. Wide Area Networking (2) This Lecture. Internet Protocol (1) Source: chapters 2.2, 2.3,18.4, 19.1, 9. Lecture 17 Overview Last Lecture Wide Area Networking (2) This Lecture Internet Protocol (1) Source: chapters 2.2, 2.3,18.4, 19.1, 9.2 Next Lecture Internet Protocol (2) Source: chapters 19.1, 19.2, 22,1

More information

Data Communication Networks and Converged Networks

Data Communication Networks and Converged Networks Data Communication Networks and Converged Networks The OSI Model and Encapsulation Layer traversal through networks Protocol Stacks Converged Data/Telecommunication Networks From Telecom to Datacom, Asynchronous

More information

Guide to TCP/IP, Third Edition. Chapter 3: Data Link and Network Layer TCP/IP Protocols

Guide to TCP/IP, Third Edition. Chapter 3: Data Link and Network Layer TCP/IP Protocols Guide to TCP/IP, Third Edition Chapter 3: Data Link and Network Layer TCP/IP Protocols Objectives Understand the role that data link protocols, such as SLIP and PPP, play for TCP/IP Distinguish among various

More information

Ethernet. Ethernet. Network Devices

Ethernet. Ethernet. Network Devices Ethernet Babak Kia Adjunct Professor Boston University College of Engineering ENG SC757 - Advanced Microprocessor Design Ethernet Ethernet is a term used to refer to a diverse set of frame based networking

More information

Module 6. Internetworking. Version 2 CSE IIT, Kharagpur

Module 6. Internetworking. Version 2 CSE IIT, Kharagpur Module 6 Internetworking Lesson 2 Internet Protocol (IP) Specific Instructional Objectives At the end of this lesson, the students will be able to: Explain the relationship between TCP/IP and OSI model

More information

The OSI Model and the TCP/IP Protocol Suite. Pritee Parwekar ANITS 1

The OSI Model and the TCP/IP Protocol Suite. Pritee Parwekar ANITS 1 The OSI Model and the TCP/IP Protocol Suite Pritee Parwekar ANITS 1 To study To discuss the idea of multiple layering in data communication and networking and the interrelationship between layers. To discuss

More information

Basic Networking Concepts. 1. Introduction 2. Protocols 3. Protocol Layers 4. Network Interconnection/Internet

Basic Networking Concepts. 1. Introduction 2. Protocols 3. Protocol Layers 4. Network Interconnection/Internet Basic Networking Concepts 1. Introduction 2. Protocols 3. Protocol Layers 4. Network Interconnection/Internet 1 1. Introduction -A network can be defined as a group of computers and other devices connected

More information

Communications and Computer Networks

Communications and Computer Networks SFWR 4C03: Computer Networks and Computer Security January 5-8 2004 Lecturer: Kartik Krishnan Lectures 1-3 Communications and Computer Networks The fundamental purpose of a communication system is the

More information

Zarząd (7 osób) F inanse (13 osób) M arketing (7 osób) S przedaż (16 osób) K adry (15 osób)

Zarząd (7 osób) F inanse (13 osób) M arketing (7 osób) S przedaż (16 osób) K adry (15 osób) QUESTION NO: 8 David, your TestKing trainee, asks you about basic characteristics of switches and hubs for network connectivity. What should you tell him? A. Switches take less time to process frames than

More information

Computer Networks Vs. Distributed Systems

Computer Networks Vs. Distributed Systems Computer Networks Vs. Distributed Systems Computer Networks: A computer network is an interconnected collection of autonomous computers able to exchange information. A computer network usually require

More information

Internetworking and IP Address

Internetworking and IP Address Lecture 8 Internetworking and IP Address Motivation of Internetworking Internet Architecture and Router Internet TCP/IP Reference Model and Protocols IP Addresses - Binary and Dotted Decimal IP Address

More information

Introduction to LAN Protocols

Introduction to LAN Protocols CHAPTER 2 Chapter Goals Learn about different LAN protocols. Understand the different methods used to deal with media contention. Learn about different LAN topologies. This chapter introduces the various

More information

ELEC3030 (EL336) Computer Networks. How Networks Differ. Differences that can occur at network layer, which makes internetworking difficult:

ELEC3030 (EL336) Computer Networks. How Networks Differ. Differences that can occur at network layer, which makes internetworking difficult: How Networks Differ Differences that can occur at network layer, which makes internetworking difficult: It is impossible to resolve all differences, and the solution is to take a simple approach (as in

More information

Computer Networks CS321

Computer Networks CS321 Computer Networks CS321 Dr. Ramana I.I.T Jodhpur Dr. Ramana ( I.I.T Jodhpur ) Computer Networks CS321 1 / 22 Outline of the Lectures 1 Introduction OSI Reference Model Internet Protocol Performance Metrics

More information

Chapter 3. TCP/IP Networks. 3.1 Internet Protocol version 4 (IPv4)

Chapter 3. TCP/IP Networks. 3.1 Internet Protocol version 4 (IPv4) Chapter 3 TCP/IP Networks 3.1 Internet Protocol version 4 (IPv4) Internet Protocol version 4 is the fourth iteration of the Internet Protocol (IP) and it is the first version of the protocol to be widely

More information

LAN Switching and VLANs

LAN Switching and VLANs 26 CHAPTER Chapter Goals Understand the relationship of LAN switching to legacy internetworking devices such as bridges and routers. Understand the advantages of VLANs. Know the difference between access

More information

Chapter 2 NETWORK LAYER

Chapter 2 NETWORK LAYER Chapter 2 NETWORK LAYER This chapter provides an overview of the most important and common protocols associated with the TCP/IP network layer. These include: Internet Protocol (IP), Routing protocols Routing

More information

Overview of Computer Networks

Overview of Computer Networks Overview of Computer Networks Client-Server Transaction Client process 4. Client processes response 1. Client sends request 3. Server sends response Server process 2. Server processes request Resource

More information

GeorgeAlmeida.com. Learn IP Subnetting in 15 minutes

GeorgeAlmeida.com. Learn IP Subnetting in 15 minutes GeorgeAlmeida.com Learn IP Subnetting in 15 minutes George Almeida 3-8-2015 Contents Preface... 2 Terms and Definitions... 3 Introduction... 3 Obtaining an IP Address for the Internet... 4 Verifying TCP/IP

More information

Network-Oriented Software Development. Course: CSc4360/CSc6360 Instructor: Dr. Beyah Sessions: M-W, 3:00 4:40pm Lecture 2

Network-Oriented Software Development. Course: CSc4360/CSc6360 Instructor: Dr. Beyah Sessions: M-W, 3:00 4:40pm Lecture 2 Network-Oriented Software Development Course: CSc4360/CSc6360 Instructor: Dr. Beyah Sessions: M-W, 3:00 4:40pm Lecture 2 Topics Layering TCP/IP Layering Internet addresses and port numbers Encapsulation

More information

Computer Networks. Definition of LAN. Connection of Network. Key Points of LAN. Lecture 06 Connecting Networks

Computer Networks. Definition of LAN. Connection of Network. Key Points of LAN. Lecture 06 Connecting Networks Computer Networks Lecture 06 Connecting Networks Kuang-hua Chen Department of Library and Information Science National Taiwan University Local Area Networks (LAN) 5 kilometer IEEE 802.3 Ethernet IEEE 802.4

More information

Internet Protocol. Raj Jain. Washington University in St. Louis.

Internet Protocol. Raj Jain. Washington University in St. Louis. Internet Protocol Raj Jain Washington University Saint Louis, MO 63131 Jain@cse.wustl.edu These slides are available on-line at: http://www.cse.wustl.edu/~jain/cse473-05/ 13-1 Overview! Internetworking

More information

INTRODUCTION TO VOICE OVER IP

INTRODUCTION TO VOICE OVER IP 52-30-20 DATA COMMUNICATIONS MANAGEMENT INTRODUCTION TO VOICE OVER IP Gilbert Held INSIDE Equipment Utilization; VoIP Gateway; Router with Voice Modules; IP Gateway; Latency; Delay Components; Encoding;

More information

ESSENTIALS. Understanding Ethernet Switches and Routers. April 2011 VOLUME 3 ISSUE 1 A TECHNICAL SUPPLEMENT TO CONTROL NETWORK

ESSENTIALS. Understanding Ethernet Switches and Routers. April 2011 VOLUME 3 ISSUE 1 A TECHNICAL SUPPLEMENT TO CONTROL NETWORK VOLUME 3 ISSUE 1 A TECHNICAL SUPPLEMENT TO CONTROL NETWORK Contemporary Control Systems, Inc. Understanding Ethernet Switches and Routers This extended article was based on a two-part article that was

More information

Backbone and WAN part 2

Backbone and WAN part 2 Backbone and WAN part 2 Backbone Architecture Switched Backbones: most common type of backbone, used in distribution layer, used in new buildings, sometimes in core layer, can be rack or chassis based.

More information

The OSI and TCP/IP Models. Lesson 2

The OSI and TCP/IP Models. Lesson 2 The OSI and TCP/IP Models Lesson 2 Objectives Exam Objective Matrix Technology Skill Covered Exam Objective Exam Objective Number Introduction to the OSI Model Compare the layers of the OSI and TCP/IP

More information

Internet Working 5 th lecture. Chair of Communication Systems Department of Applied Sciences University of Freiburg 2004

Internet Working 5 th lecture. Chair of Communication Systems Department of Applied Sciences University of Freiburg 2004 5 th lecture Chair of Communication Systems Department of Applied Sciences University of Freiburg 2004 1 43 Last lecture Lecture room hopefully all got the message lecture on tuesday and thursday same

More information

Transport and Network Layer

Transport and Network Layer Transport and Network Layer 1 Introduction Responsible for moving messages from end-to-end in a network Closely tied together TCP/IP: most commonly used protocol o Used in Internet o Compatible with a

More information

Lecture Computer Networks

Lecture Computer Networks Prof. Dr. H. P. Großmann mit M. Rabel sowie H. Hutschenreiter und T. Nau Sommersemester 2012 Institut für Organisation und Management von Informationssystemen Thomas Nau, kiz Lecture Computer Networks

More information

Based on Computer Networking, 4 th Edition by Kurose and Ross

Based on Computer Networking, 4 th Edition by Kurose and Ross Computer Networks Ethernet Hubs and Switches Based on Computer Networking, 4 th Edition by Kurose and Ross Ethernet dominant wired LAN technology: cheap $20 for NIC first widely used LAN technology Simpler,

More information

Network Models OSI vs. TCP/IP

Network Models OSI vs. TCP/IP Network Models OSI vs. TCP/IP Network Models Using a formal model allows us to deal with various aspects of Networks abstractly. We will look at two popular models OSI reference model TCP/IP model Both

More information

Protocol Data Units and Encapsulation

Protocol Data Units and Encapsulation Chapter 2: Communicating over the 51 Protocol Units and Encapsulation For application data to travel uncorrupted from one host to another, header (or control data), which contains control and addressing

More information

The IP Transmission Process. V1.4: Geoff Bennett

The IP Transmission Process. V1.4: Geoff Bennett The IP Transmission Process V1.4: Geoff Bennett Contents Communication Between Hosts Through a MAC Bridge Through a LAN Switch Through a Router The tutorial is divided into four sections. Section 1 looks

More information

Data Communication and Computer Network

Data Communication and Computer Network 1 Data communication principles, types and working principles of modems, Network principles, OSI model, functions of data link layer and network layer, networking components, communication protocols- X

More information

Chapter 2 Network Devices

Chapter 2 Network Devices Chapter 2 Network Devices Objectives Explain the uses, advantages, and disadvantages of repeaters, hubs, wireless access points, bridges, switches, and routers Define the standards associated with wireless

More information

- OSI Reference Model -

- OSI Reference Model - 1 Network Reference Models - OSI Reference Model - A computer network connects two or more devices together to share information and services. Multiple networks connected together form an internetwork.

More information

CHAPTER 2 LITERATURE REVIEW

CHAPTER 2 LITERATURE REVIEW CHAPTER 2 LITERATURE REVIEW 2.1 Routing Process Routers are amongst the most crucial components of the internet, as each bit of information on the internet passes through many routers [2]. Routing is the

More information

1 combine the characteristics of bridges and routers. 2 Repeaters operate at which OSI layer?

1 combine the characteristics of bridges and routers. 2 Repeaters operate at which OSI layer? Review questions 1 combine the characteristics of bridges and routers. Brouters 2 Repeaters operate at which OSI layer? 3 Repeaters are typically used on what type of network? A Bus B Star C Ring D Hybrid

More information

TCP IPX/SPX. 1 The Mattapan/Greater Boston Technology Learning Center.

TCP IPX/SPX. 1 The Mattapan/Greater Boston Technology Learning Center. 1 TCP Transmission Control Protocol, is a connection based Internet protocol responsible for breaking data into packets to send over a network using IP (internet protocol) IP works at the TCP/IP Internet

More information

Overview of Routing between Virtual LANs

Overview of Routing between Virtual LANs Overview of Routing between Virtual LANs This chapter provides an overview of virtual LANs (VLANs). It describes the encapsulation protocols used for routing between VLANs and provides some basic information

More information

Understand the OSI Model

Understand the OSI Model Understand the OSI Model Part 2 Lesson Overview In this lesson, you will learn information about: Frames Packets Segments TCP TCP/IP Model Well-known ports for most-used purposes Anticipatory Set Review

More information

Tutorial Questions EG/ES The tutorial questions illustrate the style of examination questions for EG/ES 3567.

Tutorial Questions EG/ES The tutorial questions illustrate the style of examination questions for EG/ES 3567. The tutorial questions illustrate the style of examination questions for EG/ES 3567. The paper will be of 3 hours duration, and each student should attempt four questions during this time. You should aim

More information

EE4367 Telecom. Switching & Transmission. Prof. Murat Torlak

EE4367 Telecom. Switching & Transmission. Prof. Murat Torlak Packet Switching and Computer Networks Switching As computer networks became more pervasive, more and more data and also less voice was transmitted over telephone lines. Circuit Switching The telephone

More information

Computer Network. Interconnected collection of autonomous computers that are able to exchange information

Computer Network. Interconnected collection of autonomous computers that are able to exchange information Introduction Computer Network. Interconnected collection of autonomous computers that are able to exchange information No master/slave relationship between the computers in the network Data Communications.

More information

51-30-10 Selecting a Firewall Gilbert Held

51-30-10 Selecting a Firewall Gilbert Held 51-30-10 Selecting a Firewall Gilbert Held Payoff Although a company may reap significant benefits from connecting to a public network such as the Internet, doing so can sometimes compromise the security

More information

IMPLEMENTING VOICE OVER IP

IMPLEMENTING VOICE OVER IP 51-20-78 DATA COMMUNICATIONS MANAGEMENT IMPLEMENTING VOICE OVER IP Gilbert Held INSIDE Latency is the Key; Compression; Interprocessing Delay; Network Access at Origin; Network Transmission Delay; Network

More information

Technical Support Information Belkin internal use only

Technical Support Information Belkin internal use only The fundamentals of TCP/IP networking TCP/IP (Transmission Control Protocol / Internet Protocols) is a set of networking protocols that is used for communication on the Internet and on many other networks.

More information

Autumn Oct 21, Oct 21, 2004 CS573: Network Protocols and Standards 1 Oct 21, 2004 CS573: Network Protocols and Standards 2

Autumn Oct 21, Oct 21, 2004 CS573: Network Protocols and Standards 1 Oct 21, 2004 CS573: Network Protocols and Standards 2 IPv4 IP: Addressing, ARP, Routing Protocols and Standards Autumn 2004-2005 IP Datagram Format IPv4 Addressing ARP and RARP IP Routing Basics Subnetting and Supernetting ICMP Address Translation (NAT) Dynamic

More information

ΕΠΛ 674: Εργαστήριο 5 Firewalls

ΕΠΛ 674: Εργαστήριο 5 Firewalls ΕΠΛ 674: Εργαστήριο 5 Firewalls Παύλος Αντωνίου Εαρινό Εξάμηνο 2011 Department of Computer Science Firewalls A firewall is hardware, software, or a combination of both that is used to prevent unauthorized

More information

Mathatma Gandhi University

Mathatma Gandhi University Mathatma Gandhi University BSc Computer Science IV th semester BCS 402 Computer Network &Internet MULTIPLE CHOICE QUESTIONS 1. The computer network is A) Network computer with cable B) Network computer

More information

Local Area Networks: Internetworking

Local Area Networks: Internetworking Local Area Networks: Internetworking Chapter 81 Learning Objectives List the reasons for interconnecting multiple local area networks and interconnecting local area networks to wide area networks. Identify

More information

The OSI Model and the TCP/IP Protocol Suite. TCP/IP Protocol Suite 1

The OSI Model and the TCP/IP Protocol Suite. TCP/IP Protocol Suite 1 The OSI Model and the TCP/IP Protocol Suite TCP/IP Protocol Suite 1 To discuss the idea of multiple layering in data communication and networking and the interrelationship between layers. To discuss the

More information

The OSI Model: Understanding the Seven Layers of Computer Networks

The OSI Model: Understanding the Seven Layers of Computer Networks Expert Reference Series of White Papers The OSI Model: Understanding the Seven Layers of Computer Networks 1-800-COURSES www.globalknowledge.com The OSI Model: Understanding the Seven Layers of Computer

More information

Indian Institute of Technology Kharagpur. TCP/IP Part I. Prof Indranil Sengupta Computer Science and Engineering Indian Institute of Technology

Indian Institute of Technology Kharagpur. TCP/IP Part I. Prof Indranil Sengupta Computer Science and Engineering Indian Institute of Technology Indian Institute of Technology Kharagpur TCP/IP Part I Prof Indranil Sengupta Computer Science and Engineering Indian Institute of Technology Kharagpur Lecture 3: TCP/IP Part I On completion, the student

More information

Course Overview: Learn the essential skills needed to set up, configure, support, and troubleshoot your TCP/IP-based network.

Course Overview: Learn the essential skills needed to set up, configure, support, and troubleshoot your TCP/IP-based network. Course Name: TCP/IP Networking Course Overview: Learn the essential skills needed to set up, configure, support, and troubleshoot your TCP/IP-based network. TCP/IP is the globally accepted group of protocols

More information

Chapter 6 Network Communications and Protocols

Chapter 6 Network Communications and Protocols Chapter 6 Network Communications and Protocols Objectives Explain the function of protocols in a network Describe common protocol suites Guide to Networking Essentials, Fifth Edition 2 Protocols Strictly

More information

Network Models and Protocols

Network Models and Protocols 669-5ch01.fm Page 1 Friday, April 12, 2002 2:01 PM C H A P T E R Network Models and Protocols 1 EXAM OBJECTIVES 1.1 Layered Network Models 1.2 The Layers of the TCP/IP 5-Layer Model 1.3 Network Protocols

More information

A host-based firewall can be used in addition to a network-based firewall to provide multiple layers of protection.

A host-based firewall can be used in addition to a network-based firewall to provide multiple layers of protection. A firewall is a software- or hardware-based network security system that allows or denies network traffic according to a set of rules. Firewalls can be categorized by their location on the network: A network-based

More information

Exhibit n.2: The layers of a hierarchical network

Exhibit n.2: The layers of a hierarchical network 3. Advanced Secure Network Design 3.1 Introduction You already know that routers are probably the most critical equipment piece in today s networking. Without routers, internetwork communication would

More information

1 Data information is sent onto the network cable using which of the following? A Communication protocol B Data packet

1 Data information is sent onto the network cable using which of the following? A Communication protocol B Data packet Review questions 1 Data information is sent onto the network cable using which of the following? A Communication protocol B Data packet C Media access method D Packages 2 To which TCP/IP architecture layer

More information

BASIC ANALYSIS OF TCP/IP NETWORKS

BASIC ANALYSIS OF TCP/IP NETWORKS BASIC ANALYSIS OF TCP/IP NETWORKS INTRODUCTION Communication analysis provides powerful tool for maintenance, performance monitoring, attack detection, and problems fixing in computer networks. Today networks

More information

SFWR 4C03: Computer Networks & Computer Security Jan 3-7, 2005. Lecturer: Kartik Krishnan Lecture 1-3

SFWR 4C03: Computer Networks & Computer Security Jan 3-7, 2005. Lecturer: Kartik Krishnan Lecture 1-3 SFWR 4C03: Computer Networks & Computer Security Jan 3-7, 2005 Lecturer: Kartik Krishnan Lecture 1-3 Communications and Computer Networks The fundamental purpose of a communication network is the exchange

More information

Communication Systems Internetworking (Bridges & Co)

Communication Systems Internetworking (Bridges & Co) Communication Systems Internetworking (Bridges & Co) Prof. Dr.-Ing. Lars Wolf TU Braunschweig Institut für Betriebssysteme und Rechnerverbund Mühlenpfordtstraße 23, 38106 Braunschweig, Germany Email: wolf@ibr.cs.tu-bs.de

More information

Lecture (02) Networking Model (TCP/IP) Networking Standard (OSI) (I)

Lecture (02) Networking Model (TCP/IP) Networking Standard (OSI) (I) Lecture (02) Networking Model (TCP/IP) Networking Standard (OSI) (I) By: Dr. Ahmed ElShafee ١ Dr. Ahmed ElShafee, ACU : Fall 2015, Networks II Agenda Introduction to networking architecture Historical

More information

ΕΠΛ 475: Εργαστήριο 9 Firewalls Τοίχοι πυρασφάλειας. University of Cyprus Department of Computer Science

ΕΠΛ 475: Εργαστήριο 9 Firewalls Τοίχοι πυρασφάλειας. University of Cyprus Department of Computer Science ΕΠΛ 475: Εργαστήριο 9 Firewalls Τοίχοι πυρασφάλειας Department of Computer Science Firewalls A firewall is hardware, software, or a combination of both that is used to prevent unauthorized Internet users

More information

Internet Protocols. Supporting Protocols and Framing. Updated: 9/30/14

Internet Protocols. Supporting Protocols and Framing. Updated: 9/30/14 Internet Protocols Supporting Protocols and Framing Updated: 9/30/14 Supporting Protocols ARP / RARP BOOTP ICMP DHCP NAT IP Supporting Protocols IP protocol only deals with the data transfer (best-effort)

More information

Introduction to Local Area Networks

Introduction to Local Area Networks For Summer Training on Computer Networking visit Introduction to Local Area Networks Prepared by : Swapan Purkait Director Nettech Private Limited swapan@nettech.in + 91 93315 90003 Introduction A local

More information

Note! The problem set consists of two parts: Part I: The problem specifications pages Part II: The answer pages

Note! The problem set consists of two parts: Part I: The problem specifications pages Part II: The answer pages Part I: The problem specifications NTNU The Norwegian University of Science and Technology Department of Telematics Note! The problem set consists of two parts: Part I: The problem specifications pages

More information

- Hubs vs. Switches vs. Routers -

- Hubs vs. Switches vs. Routers - 1 Layered Communication - Hubs vs. Switches vs. Routers - Network communication models are generally organized into layers. The OSI model specifically consists of seven layers, with each layer representing

More information

COMPUTER NETWORK SECURITY QUESTION BANK UNIT-I DATA COMMUNICATION

COMPUTER NETWORK SECURITY QUESTION BANK UNIT-I DATA COMMUNICATION COMPUTER NETWORK SECURITY QUESTION BANK UNIT-I DATA COMMUNICATION 1. Define protocol. 2. Define transmission medium. 3. What are the basic components of data communication? 4. What is dataflow? 5. List

More information

SSVP SIP School VoIP Professional Certification

SSVP SIP School VoIP Professional Certification SSVP SIP School VoIP Professional Certification Exam Objectives The SSVP exam is designed to test your skills and knowledge on the basics of Networking and Voice over IP. Everything that you need to cover

More information

Chapter 9. IP Secure

Chapter 9. IP Secure Chapter 9 IP Secure 1 Network architecture is usually explained as a stack of different layers. Figure 1 explains the OSI (Open System Interconnect) model stack and IP (Internet Protocol) model stack.

More information

9025- TCP/IP Networking. History and Standards. Review of Numbering Systems. Local Signaling. IP Addressing

9025- TCP/IP Networking. History and Standards. Review of Numbering Systems. Local Signaling. IP Addressing 9025- TCP/IP Networking History and Standards ARPA NCP TCP, IP, ARPANET PARC Collaborative Network Requirements One Protocol? Peer-to-Peer Protocols Documentation and RFCs RFC Categories Where to Find

More information

Virtual Networks and Tunnels

Virtual Networks and Tunnels Virtual Networks and Tunnels Virtual private networks via internet Use leased lines Establish VCs on an ATM network Controlled connectivity Using IP IP Tunnels: No VC Concept of encapsulation router Example

More information

Transport Layer Protocols

Transport Layer Protocols Transport Layer Protocols Version. Transport layer performs two main tasks for the application layer by using the network layer. It provides end to end communication between two applications, and implements

More information

Protocols and Architecture

Protocols and Architecture Protocols and Architecture 1 Protocol Architecture Layered structure of hardware and software that supports the exchange of data between systems as well as a distributed application (e.g. email or file

More information

Token Passing: IEEE802.5 standard. IEEE802.5 standard

Token Passing: IEEE802.5 standard. IEEE802.5 standard Token Passing: IEEE802.5 standard. 4 Mbps. maximum token holding time: 10 ms, limiting packet length. packet (token, data) format:. SD, ED mark start, end of packet 1 IEEE802.5 standard. AC access control

More information

Understanding TCP/IP. Introduction. What is an Architectural Model? APPENDIX

Understanding TCP/IP. Introduction. What is an Architectural Model? APPENDIX APPENDIX A Introduction Understanding TCP/IP To fully understand the architecture of Cisco Centri Firewall, you need to understand the TCP/IP architecture on which the Internet is based. This appendix

More information

Computer Networks 1 (Mạng Máy Tính 1) Lectured by: Dr. Phạm Trần Vũ

Computer Networks 1 (Mạng Máy Tính 1) Lectured by: Dr. Phạm Trần Vũ Computer Networks 1 (Mạng Máy Tính 1) Lectured by: Dr. Phạm Trần Vũ 1 Lecture 7: Network Layer in the Internet Reference: Chapter 5 - Computer Networks, Andrew S. Tanenbaum, 4th Edition, Prentice Hall,

More information

EITF25 Internet Techniques and Applications L5: Wide Area Networks (WAN) Stefan Höst

EITF25 Internet Techniques and Applications L5: Wide Area Networks (WAN) Stefan Höst EITF25 Internet Techniques and Applications L5: Wide Area Networks (WAN) Stefan Höst Data communication in reality In reality, the source and destination hosts are very seldom on the same network, for

More information

CCNA 1: Networking Basics. Cisco Networking Academy Program Version 3.0

CCNA 1: Networking Basics. Cisco Networking Academy Program Version 3.0 CCNA 1: Networking Basics Cisco Networking Academy Program Version 3.0 Table of Contents CCNA 1: NETWORKING BASICS...1 TARGET AUDIENCE...3 PREREQUISITES...3 COURSE DESCRIPTION...3 COURSE OBJECTIVES...3

More information

Raritan Valley Community College Academic Course Outline. CISY 253 - Advanced Computer Networking

Raritan Valley Community College Academic Course Outline. CISY 253 - Advanced Computer Networking Raritan Valley Community College Academic Course Outline CISY 253 - Advanced Computer Networking I. Basic Course Information A. Course number and Title: CISY 253- Advanced Computer Networking (TCP/IP)

More information

CSE 3461 / 5461: Computer Networking & Internet Technologies

CSE 3461 / 5461: Computer Networking & Internet Technologies Autumn Semester 2014 CSE 3461 / 5461: Computer Networking & Internet Technologies Instructor: Prof. Kannan Srinivasan 08/28/2014 Announcement Drop before Friday evening! k. srinivasan Presentation A 2

More information

THE OSI REFERENCE MODEL LES M C LELLAN DEAN WHITTAKER SANDY WORKMAN

THE OSI REFERENCE MODEL LES M C LELLAN DEAN WHITTAKER SANDY WORKMAN THE OSI REFERENCE MODEL LES M C LELLAN DEAN WHITTAKER SANDY WORKMAN OVERVIEW THE NEED FOR STANDARDS OSI - ORGANISATION FOR STANDARDISATION THE OSI REFERENCE MODEL A LAYERED NETWORK MODEL THE SEVEN OSI

More information

Final for ECE374 05/06/13 Solution!!

Final for ECE374 05/06/13 Solution!! 1 Final for ECE374 05/06/13 Solution!! Instructions: Put your name and student number on each sheet of paper! The exam is closed book. You have 90 minutes to complete the exam. Be a smart exam taker -

More information

Protocol Architecture

Protocol Architecture Protocol Architecture ed Protocol Architectures OSI Reference Model TCP/IP Protocol Stack Need for Protocols The task of exchanging information between devices requires a high degree of cooperation between

More information

IP Networking. Overview. Networks Impact Daily Life. IP Networking - Part 1. How Networks Impact Daily Life. How Networks Impact Daily Life

IP Networking. Overview. Networks Impact Daily Life. IP Networking - Part 1. How Networks Impact Daily Life. How Networks Impact Daily Life Overview Dipl.-Ing. Peter Schrotter Institute of Communication Networks and Satellite Communications Graz University of Technology, Austria Fundamentals of Communicating over the Network Application Layer

More information

Network Layer IPv4. Dr. Sanjay P. Ahuja, Ph.D. Fidelity National Financial Distinguished Professor of CIS. School of Computing, UNF

Network Layer IPv4. Dr. Sanjay P. Ahuja, Ph.D. Fidelity National Financial Distinguished Professor of CIS. School of Computing, UNF Network Layer IPv4 Dr. Sanjay P. Ahuja, Ph.D. Fidelity National Financial Distinguished Professor of CIS School of Computing, UNF IPv4 Internet Protocol (IP) is the glue that holds the Internet together.

More information

Computer Networks/DV2 Lab

Computer Networks/DV2 Lab Computer Networks/DV2 Lab Room: BB 219 Additional Information: http://www.fb9dv.uni-duisburg.de/ti/en/education/teaching/ss08/netlab Equipment for each group: - 1 Server computer (OS: Windows 2000 Advanced

More information

Network Architecture and the OSI Reference Model

Network Architecture and the OSI Reference Model Network Architecture and the OSI Reference Model Advanced Computer Networks D12 Architecture Outline The Internet and IP Network Architecture Protocols and s Encapsulation The OSI Reference Model The Seven

More information

Data Link Protocols. TCP/IP Suite and OSI Reference Model

Data Link Protocols. TCP/IP Suite and OSI Reference Model Data Link Protocols Relates to Lab. This module covers data link layer issues, such as local area networks (LANs) and point-to-point links, Ethernet, and the Point-to-Point Protocol (PPP). 1 TCP/IP Suite

More information

ASIST Administração de Sistemas

ASIST Administração de Sistemas ASIST Administração de Sistemas Aula 1 9 de Outubro de 2006 Alexandre Bragança Bibliografia: IBM Redbook: TCP/IP Tutorial and Technical Overview, Adolfo Rodriguez, John Gatrell, John Karas, Roland Peschke

More information

CS101 Lecture 19: Internetworking. What You ll Learn Today

CS101 Lecture 19: Internetworking. What You ll Learn Today CS101 Lecture 19: Internetworking Internet Protocol IP Addresses Routing Domain Name Services Aaron Stevens (azs@bu.edu) 6 March 2013 What You ll Learn Today What is the Internet? What does Internet Protocol

More information

Internetworking Microsoft TCP/IP on Microsoft Windows NT 4.0

Internetworking Microsoft TCP/IP on Microsoft Windows NT 4.0 Internetworking Microsoft TCP/IP on Microsoft Windows NT 4.0 Course length: 5 Days Course No. 688 - Five days - Instructor-led Introduction This course provides students with the knowledge and skills required

More information

Network Security TCP/IP Refresher

Network Security TCP/IP Refresher Network Security TCP/IP Refresher What you (at least) need to know about networking! Dr. David Barrera Network Security HS 2014 Outline Network Reference Models Local Area Networks Internet Protocol (IP)

More information

Internet Protocol. IP Datagram, Fragmentation and Reassembly

Internet Protocol. IP Datagram, Fragmentation and Reassembly Internet Protocol IP Datagram, Fragmentation and Reassembly IP Datagram Header Data Data (variable length) IP Packet Header number of IP protocol Current version is 4 6 has different header format IP Packet

More information

How To Understand and Configure Your Network for IntraVUE

How To Understand and Configure Your Network for IntraVUE How To Understand and Configure Your Network for IntraVUE Summary This document attempts to standardize the methods used to configure Intrauve in situations where there is little or no understanding of

More information

IT4405 Computer Networks (Compulsory)

IT4405 Computer Networks (Compulsory) IT4405 Computer Networks (Compulsory) INTRODUCTION This course provides a comprehensive insight into the fundamental concepts in data communications, computer network systems and protocols both fixed and

More information

Lecture 9. Address Resolution Protocol (ARP)

Lecture 9. Address Resolution Protocol (ARP) Lecture 9. Direct Datagram Forwarding: Address Resolution Protocol (ARP) Problem statement Routing decision for packet X has two possible outcomes: You are arrived to the final network: go to host X You

More information