Create New Article

Wiki Search

Personal tools

Network+ Tables & Charts

From Proprofs

Network+ Tables & Charts

You are here: Home > Schools > Comptia > Network+ Certification > Wiki Home > Network+ Wiki

[edit section] Acknowledgement

Thanks to Allister for compiling the tables & charts and sharing it with everyone.

[edit section] Tables & Charts

Network topologies

Topology Description Advantage Disadvantage
Star All nodes connect to a single central device Inexpensive & easy If hub fails, network down; maximum nodes = 1024
Bus All nodes connect to a common backbone Simple & less cables If backbone fails, network down; both ends must be terminated
Ring Each node is connected to two other device No collisions; less signal degeneration Expensive; difficult to troubleshoot; proprietary hardware
Mesh Each node connects to every other device Redundancy & fault tolerance Expensive; complicated; difficult to troubleshoot

Common networking standards

Standard Description Speed Access Method Topology Media
802.3 Ethernet 10, 100, 1000 Mbps CSMA/CD physical star, logical bus UTP, STP, fiber optics
802.5 Token ring 4, 16 Mbps Token passing physical star, logical ring STP
802.11 Wireless networks 1, 11, 54 Mbps CSMA/CA cellular Atmosphere
FDDI Fiber Distributed Data Interface 100 Mbps Token passing dual ring Fiber optics

Ethernet specifications

Designation Cable Type Max Length Speed Connector Topology Standard
10BASE-T Cat3 UTP 100 m 10 Mbps RJ45 star IEEE 802.3i
10BASE-FL MMF 2000 m 10 Mbps ST star IEEE 802.3j
100BASE-TX Cat5 UTP, Cat5e FTP 100 m 100 Mbps RJ45 star IEEE 802.3u
100BASE-FX Micro MMF 412 m (half duplex)
2000 m (full duplex)
100 Mbps (half duplex)
200 Mbps (full duplex)
SC star, point-point IEEE 802.3u
1000BASE-T Cat5e / Cat6 UTP (4 pairs) 100 m 1 Gbps RJ45 star IEEE 802.3ab
1000BASE-CX Twinax STP 25 m 1 Gbps HSSDC star, point-point IEEE 802.3z
1000BASE-SX Micro MMF 550 m (50u)
275 m (62.5u)
1 Gbps SC point-point IEEE 802.3z
1000BASE-LX SMF or MMF 550 m (MMF)
5000 m (SMF)
1 Gbps SC, LC point-point IEEE 802.3z
10 GBASE-SR MMF 300 m 10 Gbps 850nm serial LAN point-point IEEE 802.3ae
10 GBASE-LR MMF 10,000 m 10 Gbps 1310nm serial LAN point-point IEEE 802.3ae
10 GBASE-ER MMF 40,000 m 10 Gbps 1550nm serial LAN point-point IEEE 802.3ae

Wireless networking technologies

Standard Data Speed Frequency Transmission Type Topology Range
IEEE 802.11 Legacy 2 Mbps 2.4 GHz FHSS or DSSS Point-point 30 m
IEEE 802.11b WiFi 11 Mbps 2.4 GHz DSSS with CCK Point-point 30 m
IEEE 802.11a WiFi 54 Mbps 5 GHz OFDM Point-point 30 m
IEEE 802.11g WiFi 54 Mbps 2.4 GHz >20 Mbps: OFDM, <20 Mbps: DSSS with CCK Point-point 30 m
IEEE 802.11n WiFi 540 Mbps 2.4 GHz MIMO Point-point 50 m
Bluetooth 2 Mbps 2.45 GHz FHSS Scatternet 10 m
Infrared 100 kbps~ 16 Mbps 100 GHz ~ 1000 THz Baseband Point-point LOS 1 m
IEEE 802.16 WiMax 75 Mbps 2 GHz ~ 11 GHz, 66 GHz BPSK Point-point Cellular 30 km

The Open Systems Interconnect reference model

No Layer Function Unit Protocols/Services Devices
7 Application network application services and processes data FTP, TFTP, HTTP, SMTP, SMB, NCP, Telnet, NTP, File & Print, DNS gateway
6 Presentation encryption, formatting, compression, translation data ASCII, JPEG, GIF, TIFF, MIDI, MPEG, MIME, Quicktime gateway
5 Session establishes maintains, manages network connections and sessions data RPC, ZIP, SCP, SQL, NetBIOS, NFS, ASP, LDAP, SSL, SMB gateway
4 Transport end-end error recovery, connectivity, flow control segments TCP, SPX, UDP, NBP, NCP. NetBEUI, SCTP gateway
3 Network routing, forwarding of packets; sequencing of datagram packets IP, IPX, ARP, RARP, DHCP, BootP, ICMP, RIP, BGP, OSPF, IPSec router, brouter
2 Data Link encoding/decoding of packets into bits; frame synchronization, error checking frames MAC, LLC, PPP, ATM, frame relay, 802.11b/g, L2TP, FDDI switch, bridge
1 Physical electrical, mechanical, lightwave, radio frequency, media specifications bits Ethernet, WiFi, Token Ring, BRI, RS232, V.35 hub, NIC, WAP

Physical media types

Medium Description Types Remarks
Twisted pair Consists of multiple insulated wires that are twisted together in pairs to prevent crosstalk UTP, STP, ScTP Cat3(16MHz), Cat5(100MHz), Cat5e(100MHz), Cat6(250MHz)
Coaxial cable Consists of a center conductor surrounded by a plastic jacket with braided shield 75Ω, 50Ω RG-58 (thinnet), RG-8(thicknet), RG-62(ARCnet)
Fiber optic cable Consists of a center glass core surrounded by glass cladding and other protective materials SMF , MMF 8~10um(SMF), 50~62.5um(MMF), 125um(clad), EMI immune

Types of media connectors

Connector Description Lock Method Usage Developed by
RJ11 Registered Jack modular connector (6P2C) snap-in telephone equipments, PBX Bell Telephone Labs
RJ45 Registered Jack modular connector (8P8C) snap-in twisted pair ethernet, PoE, ISDN, T1, token ring Bell Telephone Labs
F-type F-type coaxial connector (75Ω) screw-on broadband cable, CATV, CCTV  
BNC Bayonet Nut Coupling (50Ω) bayonet thin ethernet, RF applications Bell Labs, Amphenol
ST Straight Tip fiber optic connector bayonet fiber optic ethernet AT&T
SC Subscriber/Square Connector snap-in fiber optic gigabit ethernet IBM
LC Local Connector (SFF) snap-in fiber optic gigabit ethernet Lucent
MT-RJ Mechanical Transfer Registered Jack (SFF) snap-in fiber optic ethernet AMP
IEEE 1394 FireWire (i.Link) snap-in digital devices, consumer electronics Apple, Sony, Samsung, Matshusita, IBM, JVC, …
USB Universal Serial Bus (1.1 & 2.0) snap-in digital devices, computer peripherals HP, Compaq, Lucent, Microsoft, Intel, NEC, Philips

Network connectivity devices

Device Purpose Operation Remarks
Hub Connects all nodes in a network together; transmissions received in 1 port are rebroadcast to all ports Layer 1 concentrator (passive), repeater (active), MAU
Switch Connects all nodes/segments in a network together; filters and forwards packets; isolate collision domains Layer 2 multiport bridge, configure VLANs
Bridge Connects 2 network segments with dissimilar media types; isolate collision domains within a segment Layer 2 wired or wireless
Router Connects 2 networks with different topologies; maps nodes & routes packets; isolates broadcast domains Layer 3 Brouter, IOS
Gateway Connects 2 networks with different protocols or technologies; could be hardware or software Layer 4, 5, 6, 7 connection to ISP, PABX
NIC An expansion card installed in a device to connect/interface to the network; particular to media & protocol Layer 1, 2 PCI, USB, PCMCIA, built-in M/B
CSU/DSU A 2 in 1 device used to connect a digital carrier to the network equipment; provides diagnostics & buffering - T1, T3; V.35 interface
ISDN adapter The terminal adapter used to connect to the internet via ISDN technology - BRI TA
WAP A device used to connect mobile PCs to a wired network wirelessly via RF technology Layer 1, 2 infrastructure mode, WiFi
Modem A device that changes digital to analog signal and vice versa; modulator/demodulator - POTS (V.92), xDSL, cable
Transceiver A device that transmits or receives analog or digital signals; allows a NIC to connect to a different media type - media converter, DIX/AUI
Firewall A stand-alone device or software used to protect networks from spyware, hackers, worms, phising, trojans - port blocking, packet filtering, proxy server, DMZ

Classful IP addressing

Class Range Default Subnet No of Subnets No of Hosts/Subnet
Class A ~ 126 16,777,214
Class B ~ 16,384 65,534
Class C ~ 2,097,152 254

Reserved IP address blocks

CIDR address block Description Reference Network or wire address RFC 1700 Private network (Class A) RFC 1918 Public data network RFC 1700 Reserved RFC 1797 Localhost (Loop back address) RFC 1700 Reserved - Zeroconf , APIPA RFC 3927 Private network (Class user posted image RFC 1918 Documentation and example code RFC 3330 IPv6 to Ipv4 relay RFC 3068 Private network (Class C) RFC 1918 Network benchmark tests RFC 2544 Reserved RFC 3330 Multicasts (former Class D) RFC 3171 Experimental (former Class E) RFC 1700 Broadcast -

Physical and logical addressing

Version Length Notation Delimiter Separation Supports Example
MAC 48 bits Hexadecimal Colon (user posted image, Dash (-) 8-bit hexadecimal digits (2 hex) 12x109 combinations 00:50:DA:C3:8A:F9
IPv4 32 bits Dotted-decimal Dots (.) 8-bit binary coded decimal digits 4.3x109 addresses
IPv6 128 bits Hexadecimal Colon (user posted image 16-bit hexadecimal digits (4 hex) 3.4x1038 addresses 2001:0DB8:0::0::1428:57AB

Rules of subnetting

No Rule
1 B bits => 2; R bits => 2
2 Usable subnets created = 2B - 2
3 Usable hosts per subnet = 2R - 2
4 Decimal value of the number of bits borrowed = increment of the subnets

Commonly used well-known ports

Port Name Function
20 FTP Reliable transfer of data; uses TCP
21 FTP Provides flow control; uses TCP
22 SSH Executes command and moves files; remote login protocol; uses TCP
23 TELNET Connects a remote computer to a server; uses TCP
25 SMTP Delivers emails between email servers; sending of emails; uses TCP
53 DNS Translates hostnames to IP addresses; uses TCP (zone transfers), UDP (queries)
69 TFTP Simple transfer of data; uses UDP
80 HTTP Opens a browser connection to a webpage; uses TCP
110 POP3 Delivers emails between a mail server and client; receiving of emails; uses TCP
119 NNTP Views and writes news articles for newsgroups; uses TCP
123 NTP Sets computer clock to standard time; uses UDP
143 IMAP4 Downloads emails; stores and searches messages from newsgroups; receiving of emails; uses TCP
443 HTTPS Allows browsers and servers to authenticate and encrypt network packets; uses SSL; uses TCP

Switching type comparison

Resource Circuit Switching Packet Switching
Dedicated path? yes no
Available bandwidth? fixed dynamic
Could Bandwidth be wasted? yes no
Store-and-forward transmission no yes
Each packet follows the same route? yes no
Call setup required not required
When can congestion occurs? at set-up at every packet
Charge? per minute per packet

Network protocols

Protocol Routing Addressing Naming Interoperability
IPX/SPX RIP, SAP, NLSP 12-digit hexadecimal server names only: 64 characters, no special characters; NDS Windows, Linux
NetBEUI unroutable - NetBIOS or computer names; WINS Windows
AppleTalk version1: unroutable; version2: RTMP 24-bit address version1: NBP; version2: IP naming ethernet: ELAP, token ring: token talk
TCP/IP RIP, OSPF 32-bit address DNS, ARP, RARP Windows, UNIX, Linux, Mac, Novell

Digital transmission hierarchies

Carrier Channels Data Rate Format
T1 24 1.544 Mbps North American
T3 672 44.736 Mbps
E1 32 2.048 Mbps European
E3 480 34.368 Mbps
J1 24 1.544 Mbps Japanese
J3 480 32.064 Mbps

Optical carriers

Level Data Rate
OC-1 51.84 Mbps
OC-3 155.52 Mbps
OC-12 622.08 Mbps
OC-24 1.244 Gbps
OC-48 2.488 Gbps

xDSL technologies

Type Distance Downstream Upstream Characteristic Use
ADSL 18,000 ft 1.544 Mbps ~ 6.1 Mbps 126 kbps ~ 640 kbps Most popular; used for web access and multimedia streaming
SDSL 12,000 ft 1.544 Mbps(US), 2.048 Mbps(EU) 1.544 Mbps(US), 2.048 Mbps(EU) WAN connection from company network server to phone company
HDSL 12,000 ft 1.544 Mbps (2p), 2.05 Mbps (3p) 1.544 Mbps (2p), 2.05 Mbps (3p) WAN connection from company network server to phone company
IDSL 18,000 ft 128 kbps 128 kbps Transmits data only; similar to ISDN BRI
CDSL 18,000 ft 1.544 Mbps <1.544 Mbps Used in home and small business; no splitter; known as G.lite
RADSL n/a 640 kbps ~ 2.2 Mbps 270 kbps ~ 1.1 Mbps Same as ADSL
VDSL 4500 ft 1.6 Mbps ~ 53 Mbps 1.5 Mbps ~ 2.3 Mbps ATM networks using fiber optic cable

TCP/IP protocol suite

Name Meaning Function
TCP Transmission Control Protocol Enables two hosts to establish connection and exchange network data; connection-oriented; guaranteed delivery of packets
UDP User Datagram Protocol Enables two hosts to establish connection and exchange network data; connectionless, unreliable, less overhead
FTP File Transfer Protocol Downloads or uploads files between hosts; performs directory operations; also offers authentication security
SFTP Secure File Transfer Protocol Transfer of files with SSH to provide encryption, public key authentication, and file compression; similar to FTP
TFTP Trivial File Transfer Protocol Facilitates file transfer between computers; uses lesser bandwidth and faster speed; similar to FTP; used in firmware downloading
HTTP HyperText Transfer Protocol Transfer files or web pages from web server to client web browser; uses lesser bandwidth and supports both text and graphics
HTTPS HyperText Transfer Protocol Secure Allows browsers and servers to authenticate and encrypt network packets using SSL; secure version of HTTP
SMTP Simple Mail Transfer Protocol Uses a spooled or queued method to deliver or send emails
POP3 Post Office Protocol version 3 Used to retrieve email files from the email server; can be used with or without SMTP
IMAP4 Internet Message Access Protocol version 4 Used to retrieve email files from the email server; similar to POP3 but with added features; supports Kerberos
Telnet Telephone Network A terminal emulation program that connects remote computers to a server; execute a commands using command prompt
SSH Secure Shell A suite of protocols used to log into another computer on the network, execute commands, and secure transfer of files
ICMP Internet Control Message Protocol Provides network layer management and control by sending datagrams and control messages; works with IP
ARP Address Resolution Protocol Resolves network addresses (IP) into hardware addresses (MAC); uses address resolution cache table built into every NIC
RARP Reverse Address Resolution Protocol Uses host MAC address to discover its IP address
NTP Network Time Protocol Sets computer clock to a standard time source usually a nuclear clock
NNTP Network News Transfer Protocol Used for the distribution, inquiry, retrieval, and posting of news articles and newsgroup forum messages
SCP Secure Copy Protocol Safe and secure copying of files between a local and remote computer; similar to SFTP
LDAP Lightweight Directory Access Protocol A session layer protocol that provides directory services and access to x.500 information directories
IGMP Internet Group Multicast Protocol A network layer protocol used to report multicast group membership to adjacent routers
LPR Line Printer Remote A printer protocol used to print across different NOS platforms

Network services and protocols

Name Meaning Function
DNS Domain Name System Translates and resolves IP addresses into host names or the reverse
DHCP Dynamic Host Configuration Protocol Allows a client device to request and obtain a unique IP address and other parameters from a server automatically
NAT Network Address Translation Allows a local network to use one set of IP address for internal or in-house traffic and a different set for external or internet traffic
ICS Internet Connection Sharing Connects multiple computers on a local network to the internet through a single connection and IP address; uses NAT
WINS Windows Internet Naming Service Resolves a host NetBIOS name or computer name into an IP address; used in legacy Windows
SNMP Simple Network Management Protocol Monitors the network and network devices; sends messages to different parts of the network; uses MIB
NFS Network File System Permits network users to access and used shared files; allows different computer platforms to share files and disk space
Zeroconf Zero Configuration Connects networking devices using an Ethernet cable; no configuration or DHCP required
SMB Server Message Block Shares files, directories, and services; message format used by DOS; allows UNIX/Linux and Windows machines to share files
AFP Appletalk File Protocol A file sharing protocol used with TCP/IP to permit non-apple computers to access apple servers
LPD Line Printer Daemon Processes LPR print jobs, queues, and prints files
Samba - Provides file and print services to SMB clients; runs on UNIX and Linux
ICA Independent Computing Architecture The core of Citrix presentation server that enables Windows or UNIX server to run an application for multiple users simultaneously
Apache - A popular public domain UNIX-based web server

Remote access protocols and services

Name Meaning Function
RAS Remote Access Service Used for client remote access to a network
PPP Point-Point Protocol Used to establish an internet connection between serial point-to-point links; provides for dial-up connnections to networks
SLIP Serial Line Internet Protocol Used to connect to the internet via a dial-up modem; older, slower, less reliable than PPP
PPPoE PPP over Ethernet Uses PPP over Ethernet to connect an ethernet LAN user to the internet using an ADSL or cable modem; users share a broadband connection
PPTP Point-Point Tunnel Protocol A form of encryption that provides a tunnel for secure connections over the internet; used to create VPN
VPN Virtual Private Network A private, secure, point to point connection from a company LAN to the remote users and wireless nodes using the internet
RDP Remote Desktop Protocol connects a client to a network via a terminal server and uses authentication to establish connection to run applications and printers remotely

Security protocols

Name Meaning Function
IPSec Internet Protocol Security Provides authentication and encryption over the internet; works with IPv4 and IPv6; used to secure VPN
L2TP Layer 2 Tunneling Protocol Supports non-TCP/IP protocols VPN over the internet; combines the best features of PPTP and L2F
SSL Secure Sockets Layer Uses a private key to encrypt data that is transferred over the SSL connection; service independent and can secure different network applications
WEP Wired Equivalent Privacy Encrypts and protects data packets over radio frequencies; does not offer end-end security
WPA WiFi Protected Access Offers improved data encryption and user authentication using the wireless devices MAC address; uses TKIP encryption
AES Advanced Encryption Standard A cryptographic cipher that uses Rijndael algorithm
PGP Pretty Good Privacy An encryption utility based on public key encryption designed to encrypt email transmissions
802.1x - Method for passing EAP over both wired and wireless networks; provides authentication services for wireless networks not using PPP

Authentication protocols

Name   Function
CHAP Challenge Handshake Authentication Protocol Uses a hashed algorithm MD5 that provides client response encryption; weak and one-way authentication protocol
MS-CHAP Microsoft Challenge Handshake Authentication Protocol Has two versions used in Windows systems that offers more security; version1 not compatible with version2
PAP Password Authentication Protocol The weakest authentication protocol that sends username and password in clear text over the network to be verified by RAS
RADIUS Remote Authentication Dial-in User Service An industry standard that provides authentication, authorization, and accounting services
Kerberos - A fully-fledge security system that uses secret key cryptography
EAP Extensible Authentication Protocol A general protocol often used by a wireless devices to connect to a RADIUS server; TLS uses certificates such as smart cards

Routing protocols

Name Meaning Function
RIP Routing Information Protocol Finds the quickest route between two computers; offers a maximum of 16 hops between routers before deciding that a packet is undeliverable
OSPF Open Shortest Path First A descendant of RIP that increases its speed and reliability; much used on the internet; accepts 256 hops between routers
IGRP Interior Gateway Routing Protocol A propriety protocol from Cisco that takes bandwidth, latency, reliability, and current traffic load into consideration
EGP Exterior Gateway Protocol A distance vector protocol that uses polling to retrieve routing information
BGP Border Gateway Protocol Used to span autonomous systems in the internet; used at the edge of networks; designed to supersede EGP
NLSP Netware Link Services Protocol A link state routing protocol that was designed to reduce wasted bandwidth associated with RIP
RTMP Routing Table Maintenance Protocol Used by Appletalk to ensure that all routers in the network have consistent routing information

Network operating system versions

Vendor Releases
Novell Netware 3.x, 4.x, 5.x, 6.x
Microsoft Windows NT, Windows 2000, Windows Server 2003
Apple Mac OS X, AppleShare IP
UNIX/Linux SCO ACE, RedHat

Server operating systems basic capabilities

Operating System Client Support Authentication File & Print Services Interoperability
UNIX/Linux multi-user, multitasking; GUI etc/password; NIS authentication; LDAP LPD/LPR; FAT16, FAT32, NTFS, Ext2, Ext3; NFS Windows, Linux, Netware, Mac OS
Netware multi-user, multitasking; GUI user password; keys stored in NDS; eDirectory FAT16, FAT32, NTFS, NFS, AppleShare Windows, Linux, Netware, Mac OS
Windows multi-user, multitasking; GUI domain username/password; AD LPD/LPR; FAT16, FAT32, NTFS Windows, Linux, Netware, Mac OS
Mac OS multi-user, multitasking; GUI kerberos mechanism; keychain; OD UNIX-type file system, AppleShare IP Windows, Linux, Netware, Mac OS

TCP/IP utilities

Utility Operating System Function Switches
config NetWare displays IP stack configuration  
ifconfig UNIX/Linux displays IP stack configuration  
winipcfg Windows 95/98 displays IP stack configuration  
ipconfig Windows NT/2000/XP displays IP stack configuration, release/renew DHCP IP address, flush/register DNS /all /renew /release /flushdns /registerdns
ping Windows/UNIX/Linux/Netware verifies end-to-end network connectivity; uses ICMP echo packets –t –a –n –l –f –i –r –v
tracert Windows 2000/XP/2003 traces routes to internet sites based on the number of hops and displays time taken –d –h –j –w
traceroute UNIX/Linux traces routes to internet sites based on the number of hops and displays time taken  
netstat Windows/UNIX/Linux/Netware displays protocol statistics and current TCP/IP network connections –a –b –e –r –o –s –n –p
nbtstat Windows/UNIX/Linux/Netware displays protocol statistics and current TCP/IP network connections using NetBIOS over TCP/IP –a –A –c –n –r –R –S –s
arp Windows/UNIX/Linux/Netware displays and/or modifies IP to physical address translation tables; displays current ARP cache –a –g –s –N
nslookup Windows 2000/XP/2003 queries a DNS name server; used to troubleshoot DNS and verify DNS resolution –a –d –t exit
dig UNIX/Linux nslookup equivalent  
telnet Windows/UNIX/Linux/Netware enables a computer to function as a terminal working from a remote computer –a –e –f –l –t
netuse Windows NT/2000/XP used to connect to file or print share  

Tools for network cabling and troubleshooting

Tool Usage
Wire crimper Used to affix an UTP/STP cable to a modular connector or plug
Punchdown tool Used to affix several cables to a punchdown block or a patch panel found in wiring cabinets
Media tester/certifier Used to test continuity or polarity of cables, trace shorts along the line; can’t be used on live/active wires
Tone generator Used along with a probe to verify cable continuity, identify wiring faults, determine line voltage and polarity; can be used in active wires

Common network implementation

Implementation Purpose Characteristics/Benefits Remarks
Firewall security Permits/denies public traffic based on various filtering rules; protection from internet threats ACL, DMZ
Proxy server security, performance A firewall method that caches web content for improved network performance; establish VPN for remote users web proxy, ip proxy
Antivirus software security, maintenance Software used to search/remove malicious programs on network computer hard drives; prevents infection viruses, worms, trojan horses
VLAN security, performance Better bandwidth management; reduced administration costs; well-defined groups; improved network security static/dynamic; VTP, DTP
Intranet cost, flexibility A private network based on TCP/IP which resides behind a firewall; cheaper, versatile, flexible information sharing -
Extranet security, versatility Extension of a corporate intranet; exchange data between suppliers/customers; secure corporate purchasing -
Clustering fault-tolerance, load balancing A group of redundant mirrored servers; high availability and scalability; minimized network downtime -

Network security implementation

Implementation Purpose Impact on network Remarks
Port blocking intrusion detection slows down firewalls, proxy servers
Packet filtering intrusion detection slows down firewalls, proxy servers
Authentication access control none NOS logon server
Encryption data protection slows down IPSec, PKI, PGP, Kerberos, DES

Characteristics of fault-tolerance

Item Implementation
Power UPS, SPS; backup generators, cooling fans, processors; surge suppressor; line conditioners
Link redundancy Backup links: ISDN, dial-up; microwave wireless radios; secondary ISP; clustering
Storage Hardware or software RAID; SCSI hard disks; data warehousing
Services Mission critical servers and equipments: gateways, routers, switches; SAN clusters, MSOS
Disaster recovery Backup/restore schemes; offsite storage: NAS, SAN; hot/cold spares; hot, warm, cold sites

Types of RAID

Level No of drives Description
RAID 0 2 disk stripping without fault tolerance
RAID 1 2 disk mirroring/duplexing
RAID 0+1 4 a mirror of stipes
RAID 5 3 stripping with parity
RAID 10 4 stripe of mirrors

Backup types

Type Description Clears archive bit? Sets to restore
full/normal backs up all data; longest time to backup Y full only
incremental backs up files changed or added since the last backup; faster to backup; uses more tapes Y full + every incremental
differential backs up files changed or added since the last full backup; faster to restore; uses lesser tapes N full + last differential
mirror/copy backs up all data; used to make offsite copies; N -

Types of backup tape drives

Drive Description Capacity Data Transfer Speed
QIC Quarter Inch Cartridge; formats: 3.5", 5.25" 20 GB, 50 GB 60 kbps, 125 kbps
Travan Enhancement of QIC; formats: TR4, TR5 4/8 GB, 10/20 GB 1 Mbps, 1.83 Mbps
DAT Digital Audio Tape; formats: DDS (Digital Data Storage), DLT (Digital Linear Tape) 40 GB (DDS), 160 GB (DLT) 4.8 Mbps, 20 Mbps
Mammoth An 8mm backup format used in computer systems; AIT (Advanced Intelligent Tape) 10/20 GB, 20/40 GB 3 Mbps, 6 Mbps

Troubleshooting strategy

No Step
1 Identify the symptoms
2 Identify the affected area
3 Establish what has changed
4 Select the most probable cause
5 Implement a solution and action plan
6 Test the result
7 Recognize the effects of the solution
8 Document the solution and process

IEEE Standards

Standard Description
802.1 Internetworking
802.2 Logical Link Control (LLC)
802.3 Ethernet (CSMA/CD)
802.4 Token bus LAN
802.5 Token ring LAN
802.6 Metropolitan Area Network (MAN)
802.7 Broadband technical advisory
802.8 Fiber optic
802.9 Integrated voice/data
802.10 Network Security
802.11 Wireless Networks
802.12 Demand Priority (100VG-Any LAN)
802.13 Not used
802.14 Cable modem
802.15 Wireless personal area network
802.16 Broadband wireless access
802.17 Resilient packet ring

Top 5 Contributors to this article

UsersArticle Contributions
james 2 contribs

Home  |  Site Map  |  Contact
Copyright © 2005-2014 - Privacy & Terms