Network Architecture & Standards Unit 2, Chapter 3 & 4 Why Standards?

Objectives Explain the importance of network architecture. Identify 802.x LAN standards as described by IEEE. Match the seven layers of the OSI model to network equipment and their role in cross-platform interoperability Describe the function of a network access PDU. Differentiate between connectionless and connection-oriented protocols. Describe selected basic functions of a protocol. Explain the importance of network architecture. Identify 802.x LAN standards as described by IEEE. Match the seven layers of the OSI model to network equipment and their role in cross-platform interoperability Describe the function of a network access PDU. Differentiate between connectionless and connection-oriented protocols. Describe selected basic functions of a protocol.

Architectures & Standards Networks Architecture – Principles in the design and implementation of a network Reduction in complexity, common solution Isolate network complexities from users Ability to connect different types of devices Management of the network Communications Standards – Rules to establish compatibility among similar products View Points Vendor – IBM, DEC, Microsoft, Novell Industry – IEEE, ANSI, NIST Networks Architecture – Principles in the design and implementation of a network Reduction in complexity, common solution Isolate network complexities from users Ability to connect different types of devices Management of the network Communications Standards – Rules to establish compatibility among similar products View Points Vendor – IBM, DEC, Microsoft, Novell Industry – IEEE, ANSI, NIST Explain that network architecture is a set of principles used as a basis for the design and implementation of a communications network. Describe the different types of devices, such as personal computers, routers, switches and other equipment, used in a network.

Vendor Technologies Systems Network Architecture (SNA) Digital Network Architecture (DNA) Burroughs Network Architecture (BNA) Novell (IPX/SPX - XNS) Banyan Virtual Integrated Network Services(Vines - XNS) Systems Network Architecture (SNA) Digital Network Architecture (DNA) Burroughs Network Architecture (BNA) Novell (IPX/SPX - XNS) Banyan Virtual Integrated Network Services(Vines - XNS)

IEEE 802 Standards Institute of Electrical and Electronics Engineers IEEE 802 LAN/MAN Overview and Architecture IEEE 802-2001 (R2007) IEEE Standard for Local and Metropolitan Area Networks: Overview and Architecture IEEE 802a-2003 (R2007) IEEE Standard for Local and Metropolitan Area Networks: Overview and Architecture Amendment 1: Ethertypes for Protype and Vendor-Specific Protocol Development IEEE 802b-2004 (R2007) IEEE Standard for Local and Metropolitan Area Networks - Overview and Architecture - Amendment 2: Registration of Object Identifiers IEEE 802.1™ Bridging & Management IEEE 802.2™: Logical Link Control IEEE 802.3™: CSMA/CD Access Method IEEE 802.5™: Token Ring Access Method IEEE 802.11™: Wireless IEEE 802.15™: Wireless Personal Area Networks IEEE 802.16™: Broadband Wireless Metropolitan Area Networks IEEE 802.17™. Resilient Packet Rings IEEE 802.20 Local and Metropolitan Area Networks: Overview and Architecture IEEE 802.20-2008 IEEE Standard for Local and Metropolitan Area Networks: Overview and Architecture

International Telecommunications Union Most important telecommunications standards setting body V. Standards – Connection of digital equipment to analog PSTN lines X. Standards – Connection of digital equipment to digital lines Development of the Open System Interconnect Model with International Standards Organization Basis for interconnecting dissimilar systems Most important telecommunications standards setting body V. Standards – Connection of digital equipment to analog PSTN lines X. Standards – Connection of digital equipment to digital lines Development of the Open System Interconnect Model with International Standards Organization Basis for interconnecting dissimilar systems

Open Systems Interconnect (OSI) Model

OSI Model Layers Application Layer (7) Presentation Layer (6) Where user works with at a terminal Presentation Layer (6) Code conversion & data reformatting from application - network Session Layer (5) Establishing the communications rules(pacing, accounting) Turns communications on & off Transport Layer (4) Identifies the actual address of recipient of the message Responsible for ensuring data is transmitted (retransmission) Network Layer (3) Routing message to recipient Establishes, maintains and terminates communications Data Link Layer (2) Establishing link between 2 points & packing data, block transfers Physical Layer (1) Electrical components for the communication http://www.reskit.net/MCTFAQS/The%20OSI%20Model%20as%20explained%20by%20Laura.htm Application Layer (7) Where user works with at a terminal Presentation Layer (6) Code conversion & data reformatting from application - network Session Layer (5) Establishing the communications rules(pacing,accounting) Turns communications on & off Transport Layer (4) Identifies the actual address of recipient of the message Responsible for ensuring data is transmitted (retransmission) Network Layer (3) Routing message to recipient Establishes, maintains and terminates communications Data Link Layer (2) Establishing link between 2 points & packing data, block transfers Physical Layer (1) Electrical components for the communication

More OSI X.25 standard for data transmission Used in packet switching networks 1st 3 OSI layers (physical, data link, network) Encapsulation: process that surrounds the original data or requests with control characters for routing and error checking

Protocol Data Unit

Internet Architecture Principles Multiplexing Multiple Independent data streams on one physical communication line Survivability Message gets through no matter what Service Generality Useful for multiple purposes Diverse Network Technologies Accommodate previous network technologies (Arpanet, Satellite-based networks….) Multiplexing Multiple Independent data streams on one physical communication line Survivability Message gets through no matter what Service Generality Useful for multiple purposes Diverse Network Technologies Accommodate previous network technologies (Arpanet,Satellite-based networks….)

TCP/IP Transmission Control Protocol / Internet Protocol Advanced Research Project Agency (ARPA) Arpanet TCP/IP = 4 or 5 layers of OSI Model Transmission Control Protocol / Internet Protocol Advanced Research Project Agency (ARPA) Arpanet TCP/IP = 4 or 5 layers of OSI Model The layered protocol stack that dominates data communications today is the fivelayer Internet model, generally referred to as the TCP/IP protocol suite. Describe to the students the function of each of the five layers of the TCP/IP model (Application, Transport, Internet, Network Access, and Physical layers).

OSI –TCP/IP Models OSI Model TCP/IP L7 Application L6 Presentation L5   OSI Model TCP/IP L7 Application L6 Presentation L5 Session Transport L4 L3 Network Internet L2 Data Link Data link Data link (Network interface) L1 Physical (Hardware) TCP/IP Protocol Suite and Architecture Just as Ethernet rules the roost when it comes to LAN technologies and IEEE 802.11 is the boss of the wireless LAN world, modern internetworking is dominated by the suite known as TCP/IP. Named for two key protocols of the many that comprise it, TCP/IP has been in continual development and use for about three decades. In that time, it has evolved from an experimental technology used to hook together a handful of research computers, to the powerhouse of the largest and most complex computer network in history: the global Internet, connecting together millions of networks and end devices. In this section I begin our magical tour through the mystical world of TCP/IP. J I begin with an overview of TCP/IP and a brief look at its very interesting history. I discuss the services provided in TCP/IP networks, and then explain the architectural model used under TCP/IP. I then provide a brief description of each of the most important TCP/IP protocols that are discussed in this Guide. You may have noticed that this section is relatively small, even though its title seems to encompass the entire subject of this TCP/IP Guide. The reason is that this section only provides a high-level overview of TCP/IP. Most of the content of the Guide is concerned with explaining the several dozen individual protocols that comprise TCP/IP; these can be found in other sections and subsections of the Guide. For convenience, you can also find direct links to the descriptions of these protocols in the TCP/IP Protocols topic in this section.

Protocol Stack Protocol – Set of rules used for communication between 2 points on a network What does the transportation header contain? Pg 76

Protocol Examples

Protocol Functions Encapsulation: control information (Where going? Is it right? Which protocols to use?) Fragmentation (Segmentation) & Re-assembly Error Control: using a check character to determine an error in the network access layer Synchronization Ordered Deliver (Sequencing) Addressing Multiplexing Transmission Services Fragmentation (Segmentation) & Re-assembly Encapsulation Connection Control Flow Control Error Control Synchronization Ordered Deliver (Sequencing) Addressing Multiplexing Transmission Services

Other Protocol Functions Connection Control – Connection Oriented – TCP Established and maintained before successful transmission Connectionless – UDP Communication without establishing a connection (PING) Ordered Delivery – Important to maintain order of packets – connection oriented Flow Control – Control data rate sent by transmitter Connection Control – Connection Oriented – TCP Established and maintained before successful transmission Connectionless – UDP Communication without establishing a connection (PING) Ordered Delivery – Important to maintain order of packets – connection oriented Flow Control – Control data rate sent by transmitter

Other Protocol Functions Error Control – Error Detection & Error Correction Check Sum, retransmit Sequence Numbering, retransmit Addressing – Network, Application Layer dependent Transmission Services Message priority Error Control – Error Detection & Error Correction Check Sum, retransmit Sequence Numbering, retransmit Addressing – Network, Application Layer dependent Transmission Services Message priority

Protocols Transport Data Link Ensure messages are exchanged reliably Arrival of all data at the destination Presentation in the same order as sent Virtual Circuit – Route between sender & Receiver Data Link Communication Startup Character Identification PDU identification, how to process Error Control, what scheme to use Termination Transport Ensure messages are exchanged reliably Arrival of all data at the destination Presentation in the same order as sent Virtual Circuit – Route between sender & Receiver Data Link Communication Startup Character Identification PDU identification, how to process Error Control, what scheme to use Termination

Review Questions 1. Communications standards define what needs to be done but not how to do it. a. True b. False Quiz 3 7.B

Review Questions 2. Which field in a header tells the destination of a message or PDU? a. address b. flag c. byte d. none of the above Quiz 3 8. A

Review Questions 3. It is more difficult for a machine to process a code if all of the bits are of the same duration. a. True b. False Quiz 3 9. B

Review Questions 4. The combination of the first three layers of the OSI model is the standard for the ______________. a. X.25 standard for data transmission b. V. standard c. consolidated transmission standard d. Consolidated Transmission Protocol Final 5. A

Review Questions 5. When data or a request from one layer is passed down to another layer, the data are surrounded by control characters or other information. This process is called _____________. a. enclosure b. encapsulation c. isolation d. permutation Final 6. C

Review Questions 6. The process of reassembling a message a TCP/IP packetized stream of data that has been fragmented is called __________. a. reassembly b. reconstitution c. segmentation d. togetherness Final 7. A

Review Questions 7. It is much easier for a machine to process a code if ____________________. a. it is a true binary code b. all of the characters have the same number of bits c. all of the bits are the same duration d. all of the above Final 10. D

Review Questions 8. An example of a communications medium is ____________. a. a telephone b. a personal computer c. a teleprinter d. a copper wire Final 39. D

Review Questions 9. The PSTN is an example of a _____________. a. mesh network b. star network c. bus network d. ring network Final 40. A

Review Questions 10. The OSI layer responsible for establishing the communication rules between certain machines or applications is the ______________. a. network layer b. transport layer c. session layer d. data link layer Final 41. C

Homework Assignment: Due Next Week Review: Read: Complete: Chapter 3, pp. 48-66 Chapter 4, pp. 72-82 Read: Chapter 5, pp. 90-101 Chapter 14, pp. 376-411 Complete: Assignment 2.1: Chapter 3 & 4 Multiple Choice Questions Assignment 2.2: Binary Exercise Assignment 2.3: Draw OSI Model (pg 57) by Hand Assignment: Due June 26, 2009 at 9 am Review: Chapter 3, pp. 48-66 Chapter 4, pp. 72-82 Read: Chapter 5, pp. 90-101 Chapter 14, pp. 376-411 Complete: Assignment 2.1 Assignment 2.2