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

© Agilent Technologies Copyright 2000 H7211A+212, Rev 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

© Agilent Technologies Copyright 2000 H7211A+212, Rev 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.

© Agilent Technologies Copyright 2000 H7211A+212, Rev 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

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

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

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

© Agilent Technologies Copyright 2000 H7211A+212, Rev 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

© Agilent Technologies Copyright 2000 H7211A+212, Rev Time Division Multiplexing ABBACAB A B C D

© Agilent Technologies Copyright 2000 H7211A+212, Rev Private Leased Lines Point to Multipoint Point to Point Fully Meshed

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

© Agilent Technologies Copyright 2000 H7211A+212, Rev 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

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

© Agilent Technologies Copyright 2000 H7211A+212, Rev 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

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

© Agilent Technologies Copyright 2000 H7211A+212, Rev 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.

© Agilent Technologies Copyright 2000 H7211A+212, Rev 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

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

© Agilent Technologies Copyright 2000 H7211A+212, Rev Each Protocol Layer Encapsulates Data from the Layer Above

© Agilent Technologies Copyright 2000 H7211A+212, Rev 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

© Agilent Technologies Copyright 2000 H7211A+212, Rev 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

© Agilent Technologies Copyright 2000 H7211A+212, Rev 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

© Agilent Technologies Copyright 2000 H7211A+212, Rev 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)

© Agilent Technologies Copyright 2000 H7211A+212, Rev 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

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

© Agilent Technologies Copyright 2000 H7211A+212, Rev 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 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

© Agilent Technologies Copyright 2000 H7211A+212, Rev Point-to-Point Protocol (PPP) F Synchronous PPP F Asynchronous PPP F Multilink PPP Information Control Flag Address FlagFCS 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) Type Field payload (next protocol) Synchronous PPP frame format:

© Agilent Technologies Copyright 2000 H7211A+212, Rev 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

© 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)

© 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

© 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:

© 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

© Agilent Technologies Copyright 2000 H7211A+212, Rev 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.