User:Itpastorn/dko/ccna1-3.1-2

Networking Fundamentals

Overview CCNA 1 - Module 2 (3.1)
 * Explain the importance of bandwidth
 * Identify bps, kbps, Mbps, and Gbps
 * Explain the difference between bandwidth and throughput
 * Calculate data transfer rates
 * Why layered models
 * The development of the OSI model
 * The advantages of a layered approach
 * The seven layers of the OSI model
 * The four layers of the TCP/IP model
 * Similarities and differences between the two models
 * Outline the history of networking (briefly)
 * Devices used in networking
 * The role of protocols in networking
 * Define LAN, WAN, MAN, and SAN (Lars Gunther adds: VLAN, WLAN and PAN)
 * VPN
 * Intranets and extranets

Data Networks

 * Stand alone computer
 * Sneakernet
 * LAN (but only small ones with no connection between them)
 * Inter-net-working - connecting LANs

Network History
Ethernet History

Networking devices
Terminology
 * End user devices
 * Computers
 * Printers
 * Scannerss
 * Etc
 * Network devices
 * Repeater
 * Hub
 * Bridge
 * (Workroup) Switch
 * Router
 * Network cloud
 * Etc.
 * Node (networking)
 * Host (network)
 * Data Terminal Equipment
 * Data Communications Equipment - The Cisco definition: "provides clocking"

Network topology
Physical vz. logical
 * Bus topology
 * Ring topology
 * Star topology
 * Extended star topology
 * Hierarchical topology
 * Mesh topology

Network protocolss

 * Protocol suites = collections of protocols.
 * Enables network communication between hosts.
 * A formal description of a set of rules and conventions
 * Protocols specify
 * The format of the data
 * The timing
 * The sequencing
 * Error control

LANs
Common technologies:
 * Ethernet
 * Token ring - once upon a time...
 * FDDI - once upon a time...

WANs
Common technologies:
 * Modem
 * ISDN
 * DSL
 * Frame Relay
 * T-carrier and E-carrier, e.g. T1, E1, T3 and E3
 * SONET
 * ATM
 * MPLS

MAN
"two or more LANs in a common geographic area"

SAN
A storage area network (SAN) is an architecture to attach remote computer storage devices (such as disk arrays, tape libraries and optical jukeboxes) to servers in such a way that, to the operating system, the devices appear as locally attached.
 * Dedicated
 * High-performance
 * Scalability
 * Availability

Virtual private network (VPN)
A virtual private network (VPN) is a communications network tunneled through another network, and dedicated for a specific network.

Benefits of VPN
Technologies
 * Same policies and security as a private network
 * Cost effective
 * Dialup
 * Tunneling protocols
 * Cryptography

Bandwidth

 * A Guide to Bandwidth and Throughput
 * List of device bandwidths

Importance of Bandwith

 * Finite
 * Not free
 * In demand!
 * Critical (together with latency)

The desktop
Two analogies:
 * Traffic
 * Water

Measurement (of bandwith)

 * bps
 * kbps
 * Mbps
 * Gbps
 * Tbps

Limitations
"Actual bandwidth --- is determined by a combination of the physical media and the technologies chosen"

Throughput
"Actual measured bandwith"
 * iperf

Data transfer calculation
T=S/BW (and then add some for the overhead caused by incapsulation)

Digital vz
Analog bandwith = what frequencies are occupied

Networking Models
An Introduction To The Tcp/Ip And OSI Model

Using layers to analyze problems in a flow of materials´

 * Source
 * Destination
 * Packet
 * Medium

OSI model
Evolved from: Released in 1984. "It is considered the best tool available for teaching people about sending and receiving data on a network."
 * DECnet
 * SNA
 * TCP/IP model
 * Etc.

OSI layers
Test yourself: Briefly describe each layer!
 * "Please Do Not Teach Such Petty Acronyms" (1-7)
 * "Please Do Not Throw sausage Pizza Away" (1-7)
 * "All People Seem To Need Data Processing" (7-1)
 * List of network protocols
 * Upper layer protocol
 * Lower layer protocol

Peer-to-peer communications
The layer of communication on the source computer communicates with its peer layer on the destination computer, using the layer-specific PDU. Every layer provides a service to the layer above.
 * Protocol data unit (PDU)

TCP/IP model
In detail in Module 9

Detailed encapsulation process
How Encapsulation Works Within the TCP/IP Model
 * Encapsulation
 * 1) Build the data
 * 2) Package the data for end-to-end transport (TCP or UDP segment)
 * 3) Add the network IP header (IP packet)
 * 4) Add the data link layer header and trailer (Ethernet Frame)
 * 5) Convert to bits for transmission (physical signals)

Extra topics (in addition to CCNA)
Additional terminology
 * Number of hosts involved
 * Unicast
 * Multicast (IP and MAC)
 * Broadcast (IP and MAC)
 * Synchronization
 * See also Synchronous in the ATM Dictionary
 * Asynchronous communication See also Asynchronous in the ATM Dictionary
 * . See also Isochronous in the ATM Dictionary
 * Parallelism
 * Parallel communication
 * Serial communication
 * Switching methods
 * Packet switching
 * Circuit switching
 * Cell relay
 * Connection aspects
 * Connectionless (E.g. Ethernet, IP, UDP)
 * Connection oriented (E.g. X.25, Frame relay, Asynchronous Transfer Mode (ATM), Multiprotocol Label Switching (MPLS), and TCP)

Standardization organizations
 * Institute of Electrical and Electronics Engineers (IEEE)
 * American National Standards Institute ANSI
 * Telecommunications Industry Association (TIA)
 * Electronic Industries Alliance (EIA)
 * International Telecommunications Union (ITU), formerly known as the Comité Consultatif International Téléphonique et Télégraphique (CCITT).
 * Internet Assigned Numbers Authority (IANA)
 * World Wide Web Consortium (W3C)
 * Ecma International (ECMA)
 * International Organization for Standardization (ISO)
 * Unicode Consortium
 * Post- och telestyrelsen (PTS)
 * Etc.

Additional resources (besides Wikipedia)

 * CCNA 1 Module 2 Exam Solutions at Learn Networking
 * IBM Redbook on SAN

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