Unit04
Download as PPT, PDF0 likes549 views
Protocol stacks define how devices communicate over a network. The most common protocol stack is TCP/IP, which includes TCP for reliable connections and IP for addressing. Other protocol stacks include IPX/SPX for Netware networks, AppleTalk for Macintosh networks, and NetBEUI for older Windows networks. TCP/IP became the standard due to its flexibility, interoperability, and support on many platforms. [/SUMMARY]
Unit04
- 2. Overview • Protocol • TCP/IP • IPX/SPX • Appletalk • NetBEUI
- 3. Protocol • Standards define how devices communicate with each other and access media • Once a standard is implemented in software it becomes a protocol • Protocols define how devices and applications communicate • The protocols on a network affects the way in which it functions and its ability to interface with other networks
- 4. Protocol Suite • Transmission Control Protocol/Internet Protocol (TCP/IP) – the most common of all network protocol suites, is the ‘standard’ in modern networks, used for communication on the Internet • Internet Packet eXchange/Sequence Packet eXchange (IPX/SPX) – developed by Novell, ensures communication between Netware operating systems, provides similar functionality to TCP/IP, can be routed but only to communicate with other Netware networks • AppleTalk – popular networking protocol in American educational establishments, used for communicating between devices using the Mac OS
- 5. TCP/IP • Developed for use on the Internet for the American Department of Defence • Two Parts: – TCP – responsible for connection oriented communication using error checking – IP – implemented in the addressing system used to identify devices • Although designed for the Internet it is used to build LANs, WANs and MANs • Most widely used protocol suite, used within Unix, Windows and Macintosh platforms
- 6. Features of TCP/IP • Interoperability – has become the industry ‘standard’, Netware have replaced two of its proprietary protocols (IPX and SPX) with TCP and IP • Flexibility – the multiple protocols within the suite allow a variety of implementations, eg the use of either TCP (reliable but slow) or UDP (fast and efficient, but not as reliable) • Multivendor Support – almost all network software supports it, eg Apple, DEC, IBM, Novell, Microsoft and Sun
- 7. TCP • Designed to guarantee delivery of data from the sending device to the receiving device • Requires additional control information in the header • Each data packet is placed in the correct sequence order when it is received
- 8. TCP/IP Layer
- 9. TCP Layer Encapsulation 22Bytes 20Bytes 20Bytes 4Bytes 64 to 1500 Bytes
- 10. TCP Headers
- 11. UDP • Alternative to TCP is User Datagram Protocol • Not guaranteed delivery • No preservation of sequence • No protection against duplication • Minimum overhead • Adds port addressing to IP
- 12. UDP Headers
- 13. The Internetwork Layer and IP • The TCP/IP model’s internetwork layer deals primarily with addressing and routing data
- 14. IP • One of the most important protocols • Developed to function within a UNIX environment in the days of ARPAnet • Uses connectionless delivery – it does not guarantee delivery • Main purpose is to provide logical addressing through the use of an IP address • Uses IP address to route information between networks, therefore every device requires a unique address
- 15. Understanding IP Addressing • Address consists of 4 bytes = 32 bits • Address is quoted as four dotted decimal numbers such as 134.220.198.170 = 10000110.11011100.11000110.10101010 • IP address consists of two parts the network portion, and the host portion • The network portion is used to route packets between networks • The host portion identifies the particular device on the host network • (continued in next chapter)
- 16. IPX/SPX • Novell first developed its Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX) protocol suite for use with its NetWare operating system in the 1980s • SPX is similar to TCP in that it functions at the transport layer and provides a connection-oriented service to upper-layer applications
- 17. IPX(Internetwork Packet Exchange) and Addressing • IPX/SPX-based networks require that each node on a network be assigned a unique address to avoid communication conflicts • IPX is the component of the protocol that handles addressing, addresses on an IPX/SPX network are called IPX addresses • IPX addresses contain two parts: the network address and the node address
- 18. NetBEUI • NetBIOS (Network Basic Input Output System) is a protocol originally designed for IBM to provide Transport and Session layer services for applications running on small, homogenous networks • NetBEUI can support only 254 connections, however, and does not allow for good security • Because NetBEUI frames include only Data Link layer (or MAC) addresses and not Network layer addresses, it is not routable
- 19. NetBEUI • Windows Internet Naming Service (WINS) - Provides a means of resolving NetBIOS names to IP addresses • A computer’s NetBIOS name and its TCP/IP host name are different entities, though you can have the same name for both • WINS has the same relationship to NetBIOS as DNS has to TCP/IP • WINS does not assign names or IP addresses, but merely keeps track of which NetBIOS names are linked to which IP addresses
- 20. Appletalk • The protocol suite originally designed to interconnect Macintosh computers • An AppleTalk network is separated into logical groups of computers called AppleTalk zones • An AppleTalk node ID is a unique 8-bit or 16-bit number that identifies a computer on an AppleTalk network • An AppleTalk network number is a unique 16-bit number that identifies the network to which a node is connected