1. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 Review of WAN Protocol Basics

2. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-2 Lesson 1 - Agenda F Data Communications Fundamentals F Introduction to Network Protocols F Physical Interfaces F Bit Oriented Protocols F Basic Analysis with the Internet Advisor

3. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-3 Lesson 1 - Objectives On Completion of this lesson you will be able to: F List and explain data communications fundamentals as they apply to wide area networks. F Define the term network protocol. F Explain the OSI seven-layer protocol model, peer-to-peer communications and protocol encapsulation. F Explain bit oriented protocol and give examples. F Identify and describe the different interfaces and components of the Internet Advisor. F Demonstrate how to connect the Internet Advisor to a network under test.

4. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-4 Data Communications Fundamentals F Communications Modes F DTE/DCE Terminology F Wide Area Analog/Digital Transmission F Multiplexing F Private Leased Lines F Public Switched Data Networks

5. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-5 Communication Mode Full Duplex Half Duplex Simplex one direction always both directions always alternate one direction and then the other

6. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-6 DTE/DCE Terminology Customer Premise Wide Area Network Full Duplex Line (DCE) EQPT (DTE) Data Terminal Equipment (DTE) Data Circuit-Terminating Equipment (DCE)

7. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-7 Wide Area Analog/Digital Transmission modem analog transmission typically asynchronous typically low speed (<=56kbps) digital transmission typically synchronous typically high speed (>=56kbps) DSU/CSU

8. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-8 Multiplexing F Transmission of more than one signal on a single communications line F Increases the number of communications sessions that can be maintained at one time F Various types –Time Division Multiplexing –Frequency Division Multiplexing

9. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-9 Time Division Multiplexing ABBACAB A B C D

10. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-10 Private Leased Lines Point to Multipoint Point to Point Fully Meshed

11. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-11 Public Switched Data Networks F X.25 F Frame Relay F ATM F SMDS F ISDN

12. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-12 Summary of Data Communications Fundamentals F Binary communications F Most often serial in networks F Full duplex communications occurs in both directions F DTE on customer site while DCE on WAN F Multiplexing allows more than one communications channel on the same line F Time division multiplexing F WAN cover large distances

13. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-13 Introduction to Network Protocols F Definition F Protocol Functions F ISO Reference Model F Peer to Peer Communications F Data Encapsulation from Higher Layers

14. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-14 Definition of Communications Protocol F Set of communications rules F Defines addressing F Defines syntax and semantics F Allows communications between disparate systems –Communication rules –Connection control

15. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-15 One Adam 12, HQ. What’s your 10-22? Over. HQ, One Adam 12. I’m going 10-22 at DD for a cuppa java. Over. Radio Communications Protocol

16. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-16 ISO Reference Model Physical Application Presentation Session Transport Network Data Link Responsible for the transmission of bits. Includes the mechanical, electrical and functional physical interface. Responsible for ensuring error-free, reliable flow of data acrossa physical link. Responsible for end-to-end connectivity through the network. Includes routing and flow control. Responsible for moving data between nodes; providing reliable or unreliable data transfer. Includes packet fragmentation, error detection, and retransmission. Responsible for establishing, maintaining and terminating logical connections. Responsible for format and code conversion. Includes formatting the syntax of data. Provides access to the network for the end user or software application.

17. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-17 F Addressing F Connection control F Ordered delivery and sequencing F Flow control F Error control Protocol Functions F Segmentation and reassembly F Encapsulation (control plus data) F Multiplexing –Message –Other protocols

18. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-18 Peer-to-Peer Communications Physical Application Presentation Session Transport Network Data Link Application Presentation Session Transport Physical Network Data Link Physical Network Data Link

19. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-19 Each Protocol Layer Encapsulates Data from the Layer Above

20. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-20 Protocol Layers and Stacks F WAN protocol analysis focuses on the lower three layers –Physical, Data Link and Network F Different protocol stacks often share the same lower three layers –For example, IP, IPX and SNA over Frame Relay

21. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-21 Protocol Summary F Protocols are sets of rules that allow computer with different characteristics to communicate with one another F Protocol stacks share common lower layers for actual communication F Peer-to-Peer communication occurs between upper layers F Lowest three layers often involved in network analysis and troubleshooting

22. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-22 Physical Interfaces F Physical interfaces are hardware components that attach to the physical media that transmit and receive network signals F Physical interfaces are associated with one or more protocols that utilize the interface to perform the function of the lower layers of the ISO reference model F Physical interface standards are sets of common features that manufacturers use to produce products that operate with one another

23. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-23 Typical WAN Physical Interfaces F RS-232/V.24 F V.35 F RS-449/V.36 F T1 F E1 F ISDN Basic Rate Interface (BRI) F ISDN Primary Rate Interface (PRI)

24. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-24 Introduction to Bit-Oriented Protocols F Definition F Data Communications Today: Bit- Oriented Protocols F Examples of Bit-Oriented Protocols F The Control Field Specifies the Frame Type F Point-to-Point Protocol F Bit-Oriented Protocols Summary

25. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-25 Data Communications Today: Bit-Oriented Protocols 01 E3FCSThe quick brown fox... Data Control Flag Address FlagFCS

26. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-26 Examples of Bit-Oriented Protocols F SDLC (Synchronous Data Link Control) F HDLC (High-level Data Link Control) F LAP-B (Link Access Procedure-Balanced) F ADCCP (Advanced Data Communications Control Procedures) F And many others 01111110 8 bits8 or 16 bits 8 or 16 bitsoptional (multiple of 8 bits)16 bits8 bits payload (next protocol) frame type identification, frame numbering link level addressing Data Control Flag Address FlagFCS Frame delineation

27. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-27 Point-to-Point Protocol (PPP) F Synchronous PPP F Asynchronous PPP F Multilink PPP Information Control Flag Address FlagFCS 01111110 8 bits 8 bits 8 bits 16 bitsoptional (multiple of 8 bits)16 bits8 bits next protocol type field 03 hex identifies PPP information frame not used (FF hex) 1111111100000011 Type Field payload (next protocol) Synchronous PPP frame format:

28. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-28 Bit-Oriented Protocol Summary F Bit oriented protocols can transmit more types of data than can character oriented protocols F Fields within the protocols (not control characters) manage network overhead and physical layer maintenance

29. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 Connecting the Agilent Technologies Internet Advisor to the Network Under Test modem Asynchronous RS-232C/V.24 (RS-449/V.36 or V.35) RS-232C/V.24 (RS-449/V.36 or V.35)

30. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 Connecting the Agilent Technologies Internet Advisor to the Network Under Test Synchronous DSU/CSU T1 DSX CEPT - E1 RS-232C/V.24 RS-449/V.36 X.21 or V.35 T1 network, CEPT - E1 or DDS 4-wire RR

31. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 Interface Configuration F DTE clock source: DTE or DCE (default) F Data sense: normal, inverted, NRZI-external RS-232C/V.24 RS-449/V.36 V.35 V-series interfaces include: F Bits/second or Interface configuration:

32. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 Agilent Technologies Internet Advisor Configuration Menu F Interface/Protocols –Data source –Monitor options –Protocols F Decode Table F Filters/Counters F Log –Disk logging options –Disk logging configuration

33. © Agilent Technologies Copyright 2000 H7211A+212, Rev. 2.0 1-33 Lesson 1 - Review You should be able to: F List and explain data communications fundamentals as they apply to wide area networks. F Define the term network protocol. F Explain the OSI seven-layer protocol model, peer-to-peer communications and protocol encapsulation. F Explain bit oriented protocol and give examples. F Identify and describe the different interfaces and components of the Internet Advisor. F Demonstrate how to connect the Internet Advisor to a network under test.