Intro to networking

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Information about Intro to networking

Published on February 14, 2008

Author: Veronica1


Intro to Networking:  Intro to Networking Philip Ashman Asst. Prof. Okanagan College Dept of Network & Telecommunications Engineering Technologies Objective:  Objective A quick note of reference. The information contained in this presentation is all information that has been and can be readily found on the Internet. You are free to use and borrow this material as I have borrowed from others. The goal is to provide a basic understanding of common networking and security terminology, as well as some of the next generation internet services known as Web 2.0. The scope of this presentation is far too wide to cover any one of the aforementioned topics in detail, but as usual our good friends at Google, Wikipedia, and Cisco can provide you with more information than you could possibly consume! What is a Network:  What is a Network “Computer networking is the scientific and engineering discipline concerned with communication between computer systems. Such networks involve at least two devices capable of being networked with at least one usually being a computer. The devices can be separated by a few meters (e.g. via Bluetooth) or thousands of kilometers (e.g. via the Internet). Computer networking is sometimes considered a sub-discipline of telecommunications.” Quoted from Wikipedia Slide5:  Sharing hardware or software Centralize administration and support E.g. print document E.g. Internet-based, so everyone can access the same administrative or support application from their PCs Intro to Networking Computer Networking Models:  Computer Networking Models Models, or protocol stacks, are organized into layers. This organizes the process into modules simliar to breaking programming code into subroutines OSI (Open Systems Interconnection) mnemonic “All People Seem To Need Data Processing” If you ever take a test on networking, you’ll have to now this, otherwise it is best to stick to the simplified model. Simplified 4/5 Layer Model:  Simplified 4/5 Layer Model Data Link & Physical Layer (Layer 1 &2) Most common protocol and media is Ethernet over copper twisted pair or fiber optic cable. Usually referenced as 10Base, 100BaseT, 1000BaseT for 10/100/1000Mbit/s on “T”wisted pair, or 10BaseFX, 100BaseFL, 1000BaseSX/LX/ZX for 10/100/1000Mbit/s over Fiber optics.The max distance for a single 10/100/1000 BaseT connection is 90M + 10M for patch cables. Transport/Network Layer (Layer 3 & 4) Most common protocol is TCP/IP. IP is used at layer 4 to control the addressing, TCP/UDP is used at layer 3 for flow control and connection management Application Layer (Layer 5,6 & 7) Applications that use the Layer 3/4 protocols to communicate. Eg: our Web Browsers, network printing, file sharing, skype, msn messenger etc… Slide8:  Intro to Networking Depending on one’s perspective, we can classify networks in different ways Based on transmission media: Wired (UTP, coaxial cables, fiber-optic cables) and Wireless Based on network size: LAN and WAN (and MAN) Based on management method: Peer-to-peer and Client/Server Based on topology (connectivity): Bus, Star, Ring Transmission Media:  Transmission Media Transmission Media :  Two main categories: Guided Twisted-Pair cables: Unshielded Twisted-Pair (UTP) cables Shielded Twisted-Pair (STP) cables Coaxial cables Fiber-optic cables UnGuided Wireless transmission, e.g. radio, microwave, infrared, sound, sonar Transmission Media Twisted Pair Cable:  Twisted Pair Cable Most desktop network connections consist of 24 gauge copper wires twisted into pairs. Twists in wire keep down interference from electro magnetic interference (fluorescent lights, motors etc..) The quality and specifications of the twisted pair cables are categorized into a number of categories, but most users today are familiar with Cat5/5e or Cat6 Cat6 has more twists than Cat5e and allows for higher frequencies. Cat5e and above is recommended for all networking installations, although for Gigabit ethernet use Cat6 if possible. Twisted Pair Cable:  Twisted Pair Cable The wiring within a building usually and to the data outlet in the wall uses a solid copper core whereas a patch cable connecting your computer to a wall. If the pair of wires is not twisted, interference will affect the closer wire more than the further one, thereby causing errors. Twisting the pairs allows for the interference to spread equally over each pair allowing for common mode interference cancellation Twisted-Pair Cables:  By sending half the signal down one wire in a pair, negating half the signal and sending it down the other wire in the pair, a subtraction at the other end will bring the signal back to it’s original amplitude and cancel out the interference. Twisted-Pair Cables Unshielded Twisted-Pair (UTP) :  Typically wrapped inside a plastic cover (for mechanical protection) UTP consists of 8 Strands, 4 pairs. They are usually terminated with an RJ45 connector according to the EIA/TIA 568A/B specs which indicates the order of the pairs. 10/100BaseT uses pairs 2 & 3 on pins 1,2, 3 & 6 Metal Insulator Unshielded Twisted-Pair (UTP) 4 Pairs Plastic Cover Shielded Twisted-Pair (STP):  STP cables are similar to UTP cables, except there is a metal foil or braided-metal-mesh cover that encases each pair of insulated wires Shielded Twisted-Pair (STP) Categories of UTP Cables:  EIA classifies UTP cables according to the quality Categories 1,2,4 used to exist, but you can’t buy them any more: Category 3 At least 3 twists per foot, for up to 10 Mbps (common in phone networks in residential buildings) Category 5 (or 5e) Up to 100 Mbps (common for networks targeted for high-speed data communications) Category 6 More twists than Cat 5, up to 1 Gbps and uses 23 Gauge wire. Also rated up to 10Gbps for 35m. Categories of UTP Cables Coaxial Cables:  In general, coaxial cables, or coax, carry signals of higher freq (100KHz–500MHz) than UTP cables Outer metallic wrapping serves both as a shield against noise and as the second conductor that completes the circuit Coaxial Cables Fiber-Optic Cables:  Light travels at 3108 ms-1 in free space Refraction occurs when light goes between mediums of different densities with light bending away from the normal when it enters a less dense medium The critical angle is the point at which the light is reflected back. Beyond the critical angle  total internal reflection Fiber-Optic Cables Fiber-Optic Cables:  An optical fiber consists of a glass core (denser material) and a plastic cladding (less dense material) Light is transmitted through the core and bounces back and forth along the core (as a result of the refraction index between the core and cladding) at a specific angle called the mode. Common light sources include LEDs and lasers, although lasers allow for longer distances. Fiber-Optic Cables Fiber Optic Cables:  Fiber Optic Cables Fiber Optic cable usually falls into two major categories, either Multi-mode or Single-mode. Multi-mode has a glass core with a diameter of about 62.5/50 and allows light to travel at ‘multiple’ angles (modes) down the core at a specific wavelength (Usually 850nm or 1300nm) Single mode has a glass core with a diameter of about 9  and allows light to travel at a ‘single’ angle (mode) down the core at a specific wavelength (Usually 1550nm) Fiber Optic Cables:  Fiber Optic Cables Advantages and Disadvantages Noise resistance External light is blocked by outer jacket Less signal attenuation A signal can run for miles without regeneration (currently, the lowest measured loss is about ~4% or 0.16dB per km) Higher bandwidth Currently, limits on data rates come from the signal generation/reception technology, not the fiber itself Cost Optical fibers are more expensive than copper Installation/maintenance Any crack in the core will degrade the signal, and all connections must be perfectly aligned Wireless:  Wireless Protocols in the 2.4GHz range are susceptible to interference from microwave ovens, cordelss telephones and blue tooth. These are unregulated frequencies, but hopefully one or the other is smart enough to hop frequencies and reduce interference 802.11b and g devices can use the same access points, but 802.11a requres separate (or dual) antennae. (makes sense as it uses a different freq.) Wireless:  Wireless There are proprietary extensions to boost the speed (usually advertised as 108G), but MIMO (Multiple-in Multiple-out) will likely be used to expand the bandwidth of existing technologies. MIMO is a multi-antenna communication systems where the transmitter has multiple antennas capable of transmitting independent signals and the receiver is equipped with multiple receive antennas. Ie send data in parallell. Wireless Security:  Wireless Security When setting up your wireless access point learn how to log in to it and change the default settings! Create a unique password Create a unique SSID Turn off SSID Broadcast Turn on WPA-2 Pre-Shared Key encryption (may have to upgrade firmware) Turn on MAC address filtering Turn down the power settings if you have a small area to cover. Local Area Network (LAN) & Wide Area Network (WAN):  Local Area Network (LAN) & Wide Area Network (WAN) Slide28:  Small network, short distance A room, a floor, a building Limited by no. of computers and distance covered Usually one kind of technology such as Ethernet throughout the LAN Often server a single location within an organization Examples: Network inside a Student Computer Lab Network inside Okanagan College Network inside your home Local Area Network Slide29:  A network that uses long-range telecommunication links to connect 2 or more LANs/computers housed in different places far apart. Towns, states, countries Examples: Inter/Intra-City Connections Internet WAN Office Your home Canada Wide Area Network (WAN) Slide30:  Example WAN technologies: ISDN – Integrated Service Digital Network BW: Basic Rate: 192 Kbps Primary rate: 1.544Mbps T-Carriers ― basically digital phone lines BW: T1: 1.544Mbps T3: 28T1=approx 45Mbps Frame relay BW: 56K to 1.544Mbps or even higher SONET – Synchronous Optical Network BW: Multiples of OC1: 51.84Mbps Supports OC12 and up to OC192 (9953.28Mbps) or even higher in the future WAN Slide31:  Example of WAN: Broadband Cable Network Cable TV services have been extensively developed in most modern cities Cable TV companies try to make use of their coaxial cable installed (that are supposed to carry TV signals) to deliver broadband data services Many cable network wiring has been replaced with hybrid fiber-coax (HFC) ― i.e. use of fiber-optic cable to connect to the subscribers’ buildings, and then the original coaxial cable to connect to each household Broadband Cable Network Slide32:  The connection is shared by a number of subscribers, hence may raise performance and security problems Fiber-optic cable Cable company Coaxial Cable TV PC Cable Drop Broadband Cable Network Slide33:  Shaw is also providing an asymmetrical service. Downstream: max 25 Mbps Upstream: max 1 Mbps Need a special Cable modem Ethernet link to PC Coaxial link from cable TV socket Terayon Cable Modem Shaw Cable Telco Network:  Telco Network Example of WAN: Telco Carrier ADSL Network Telco services have been in existance since the beginning of the telephone Telco companies make use of the existing copper phone cable in homes to deliver broadband data services via Assymmetric Digital Subscriber Line Network Telus are currently upgrading their infrastructure bring fiber optic cable closer to homes and neigbourhoods in order to be able to offer higher speed services such as IPTV and digital phone services. Slide35:  Each connection is shared by a number of subscribers, hence may raise performance and security problems Fiber-optic cable Telco company Copper Cable Local Telco Office Telco Network Fiber optic Home Business Slide36:  Asymmetric Digital Subscriber Line (ADSL) is an asymmetrical technology Downstream: max 36 Mbps Upstream: max 10 Mbps May be reduced to 3 – 10 Mbps downstream and 2 Mbps upstream, depending on no. of subscribers Need a special ADSL modem Telus ADSL Telus ADSL:  Telus ADSL Depending on whether Telus have your ADSL signal come in on the same wires as your telephone, you may need to install a Microfilter to avoid poor phone quality. Microfilter installation is simple and requires no tools or telephone rewiring. Just unplug the telephone device from the baseboard or wall mount and snap in a microfilter, then snap in the telephone device. Peer to Peer Networks Vs Client Server Networks:  Peer to Peer Networks Vs Client Server Networks Slide40:  Peer-to-peer network is also called workgroup No hierarchy among computers  all are equal No administrator responsible for the network Peer-to-peer Peer-to-Peer Networks Slide41:  Advantages of peer-to-peer networks: Low cost Simple to configure User has full accessibility of the computer Disadvantages of peer-to-peer networks: May have duplication in resources Difficult to uphold security policy Difficult to handle uneven loading Where peer-to-peer network is appropriate: 10 or less users No specialized services required Security is not an issue Only limited growth in the foreseeable future Peer to Peer Networks Slide42:  Network Clients (Workstation) Computers that request network resources or services Network Servers Computers that manage and provide network resources and services to clients Usually have more processing power, memory and hard disk space than clients Run Network Operating System that can centralize management of not only data, but also users, groups, security, and applications on the network Servers often have a more stringent requirement on its performance and reliability Clients-Server Networks Slide43:  Advantages of client/server networks Facilitate resource sharing – centrally administrate and control Facilitate system backup and improve fault tolerance Enhance security – only administrator can have access to Server Support more users – difficult to achieve with peer-to-peer networks Disadvantages of client/server networks High cost for Servers Need expert to configure the network Introduce a single point of failure to the system Client-Server Networks Slide44:  3 basic types? Bus Topology Ring Topology Star Topology Network Topology Slide45:  Bus Topology Simple and low-cost A single cable called a trunk (backbone, segment) Only one computer can send messages at a time Passive topology - computer only listen for, not regenerate data Star Topology Each computer has a cable connected to a single point More cabling, hence higher cost All signals transmission through the center core; if down, entire network down Depending on the intelligence of core, two or more computers may send message at the same time Network Topology Slide46:  Star Topology Bus Topology BNC T-Connector Coaxial cable Network Card Network Topology Slide47:  Ring Topology Every computer serves as a repeater to boost signals Uses Token passing to send data, where only the computer who gets the token can send data Disadvantages Difficult to add computers More expensive If one computer fails, whole network fails T T T Topology Protocol Basics:  Protocol Basics Ethernet Addressing (Layer 2):  Ethernet Addressing (Layer 2) Since there can be many users on an ethernet network, everyone has to have their own unique address. This is called the Media Access Control (or MAC) address, or sometimes ethernet address, physical address, adaptor address, hardware addres, etc. It’s a 12-digit (48 bit) hexadecimal address that is unique to that ethernet adaptor and no other in the world. It can be written as 00:30:65:83:fc:0a or 0030.6583.fc0a or 003065:83fc0a or 00-30-65-83-fc-0a but they all mean the same thing. The first 6 digits are the Vendor code, (003065 belongs to Apple), the last 6 are the individual inteface’s own. Like a car’s VIN. See to look up some vendor codes. Hubs vs. Switches:  Hubs vs. Switches Hubs Shared media devices Everyone sees everyone’s packets but each device only pays attention to those specifically directed to it, or to broadcasts. Not too secure, but cheap. Most wireless still qualifies as a “hub,” while actual wired ethernet hubs are becoming hard to find now. Hubs vs. Switches:  Hubs vs. Switches Switches Not shared most of the time. The switch pays attention to the packets and makes a table of the “sender” ethernet addresses (it removes old data after a while). When a packet comes along whose destination address is in the table (because that host has recently “talked” and identified itself) the packet only goes to that port. Unknown packets and broadcasts still go to all ports, but overall, there are nearly no collisions and is generally more secure. Switches are now much more common than hubs. Finding your Ethernet Address:  Finding your Ethernet Address On Windows 95/98, from the “run” menu type “winipcfg” On Windows NT, 2000 and XP, open a command window and type “ipconfig /all” On MacOS 9, open the TCP/IP control panel and select “Get info” On MacOS X and most Unix or Unix-like systems, from a terminal, type “ifconfig –a”. This address can be used for the MAC address filtering on a wirelss router and is also required by Telus in order for a device to connect to the Internet on their ADSL network. (This can be done online by going to Network Layer (Layer 3):  Network Layer (Layer 3) Devices are connected together with Ethernet swithes to form a Network. Networks are connected together using Routers to form Internetworks. The Internet is one big Internetwork. Each machine on a network has unique layer 2 (eg: ethernet) address, each Network is assigned a unique block of layer 3 (eg Internet Protocol (IP) ) addresses. In IP, this is called a subnet. The block of layer 3 addresses uniquely identifes a network on the Internetwork, and each layer 3 address in the block uniquely identifies each device. Although IP is by far the most predominant protocol in use, there are others such as AppleTalk, Netware, etc.) Internet Protocol (IP):  Internet Protocol (IP) Devices talk to each other on an Ethernet network using each others MAC Address. However on the internet they communicate using IP Addresses. The Internet Protocol (IP) is the Network layer protocol used on the Internet! It’s so handy that most everyone uses it on all their networks big and small. Very Scalable allowing it to support the ever-expanding Internet. IP Addressing:  IP Addressing IP addresses consists of 4 “octets” such as: Each “octet” consists of numbers between 0 and 255 (or 00 and FF in hex! Don’t ask why ethernet is in hex but IP isn’t, they just are. However the next generation of IP, IPV6, does use hex) An IP Address works is similar to the way a phone number has an area code and local prefix etc. but more flexible. Your computer can tell when you are trying to talk to another network based on an assigned subnet mask. (I will explain this if asked, but you are opening a whole can of worms!) IP Domain Name Resolution (DNS):  IP Domain Name Resolution (DNS) Your company or office is usually assigned a block IP addresses by an Internet Service Provider such as Telus, or you can apply to get your own from ARIN ( However you can register a Domain name througn any number of Internet Name reistrars. Since most people find it easier to remember names instead of numbers, IP numbers can and almost always are associated with IP Domain names. Your computer, however, needs a number, so the Domain Name System (DNS) exists to make everyone happy. DNS:  DNS A name, such as “” tells you the first (or top) level domain is “.ca”, for domains in Canda, the second level bc, and third that it is part of okanagan college’s network. The label Technologies is a specific machine on this network. If you want the number for a host name within you’ll have to ask a DNS server to give it to you. Every domain has a local Domain Name server it can use, which is found the same way you discovered your Ethernet address. (The comand ipconfig, or the Support tab of the LAN Connection properties in Windows XP IP Routing:  IP Routing IP Routing answers the question of “How do you get to that network from this one?” As mentioned previously, your computer can use the IP subnet mask to determine whether the destination IP address is on a remote network. If the address is to be sent to a remote network, then the data is encapsulated in an IP packet, which is encapsulated in an Ethernet Frame and sent to the Ethernet address of the local Router, or gateway. The router looks inside the Ethernet packet, checks out the destination IP address, and makes a decision on which interface to repackage the IP Packet and send it on it’s way. Routers:  Routers A router’s job is to keep track of its directly connected networks, maybe learn about other remote networks, and send traffic to the appropriate network based on the Layer 3 address. (Of course this is likely to be the IP Address) The router is the traffic cop of the internet. Most home routers usually only have two connected networks. One to your home network, and the other to the Internet. Therefore it knows that if the destination IP address is not on the home network, then it simply has to send it on upstream to the next router. From then on, that is where things get complicated! A great movie describing this process is called Warriors of the Net ( DHCP:  DHCP Dynamic Host Configuration Protocol All the information your computer needs to communicate on an IP network (eg the IP Address, Subnet Mask, Gateway and Domain Name Server) is assigned automatically by a server called the DHCP server. If you have a small wireless router at home, then this router acts as a DHCP server and assigns all the appropriate IP information for you home network. However this router is also a DHCP client since it gets it’s external IP information automatically from the upstream services provider (Usually Shaw or Telus) Troubleshooting:  Troubleshooting You can’t introduce networking without including the tools Ping and Traceroute. Ping Sends a small packet to a host which may or may not choose to reply to it, and logs the time of how long the packet takes to get back. Lack of a reply doesn’t always indicate a problem with the host or network, but it’s a good start toward testing connectivity issues. Unfortunately this ability is also a major security threat as hackers have used this tool to generate a Denial of Service. Nevertheless, it is often used within Local Area Networks. Troubleshooting:  Troubleshooting Traceroute Traceroute asks all routers along the path between you and the destination host if they’d like to respond to you, and logs the time it takes each of 3 requests take to get back to you. Some routers may not respond, but may still pass the traceroute packet along, and many hosts will not reply to the traceroute inquiry at all. Lack of a reply doesn’t always indicate a problem with the host or network, but again it’s a good start toward looking for bottlenecks. Onces again, there is also a threat of Denial of Service attacks using this tool and therefore many adminstrators block extneral traceroute requests from getting through their Routers. Security Tips:  Security Tips Topics:  Topics Windows XP Professional Security Setting Up a New PC Safely Secure Windows Configuration Software Tools for Better Security Good Security Practices for You Passwords vs. Pass Phrases “Malware” and “Phishing” Scams Windows Security Top 10 List Other Security Resources What’s the Threat?:  What’s the Threat? Viruses, Hackers and Worms - Oh, My! Purists reserve the term “hacker” for ace programmers, not “attackers” “Virus” is also an overworked term Internet worms, mass-mailing worms, viruses (infectors), Trojan Horses, backdoors, rootkits, bots, zombie networks, spyware, hijacking… The best general term is “malware” You Get the Idea: It’s a Jungle Out There! And an oz. of protection is worth a lb. of cure A Few Assumptions:  A Few Assumptions Much of What Follows Assumes That You have administrator rights for your PC If you have local technical support staff, you have their blessing to make changes to your PC’s configuration You understand that changing security-related settings can impair functionality: You might have to undo some changes User Rights & Privileges:  User Rights & Privileges What Are “Administrator Rights”? A User in the Administrators Group Can modify or delete all files, including (with some protections) system files Can modify the Windows registry Can define local security policies Has more or less total control Because of How Windows Applications Are Designed, Administrator Rights Are Often Necessary for “Normal Use” Primary XP user has administrator rights Out of the Box:  Out of the Box You Just Got a New PC: Now What? It’s not securely configured by default Security software is probably missing The “survival time” of an unpatched PC See First: Don’t Put It on the Network! Do set strong passwords or pass phrases Do disable File & Printer Sharing Do enable the Windows Firewall Do place your machine behind a dedicate firewall Configure Your Network Settings Now you can connect to the Internet So You’re on the Internet…:  So You’re on the Internet… Go to Install all critical updates and service packs Reboot and revisit the Windows Update site Lather, rinse, repeat… Install Various System tool Download and install an AntiVirus product (AVG, PC-Cillen, Nod32, Kapersky, MS Live Onecare) Download and install SpySweeper, MS Defender, Spybot) Note on Windows File Sharing:  Note on Windows File Sharing Always Disable Unneeded Services File & Printer Sharing Is an Open Door, so use with caution, certainly use permissions. Go to Start | Settings | Control Panel Click “Switch to Classic View” Double-click “Network Connections” Right-click “Local Area Connection” Choose Properties Uncheck “File and Printer Sharing” Passwords vs. Pass Phrases:  Passwords vs. Pass Phrases Security: A Tradeoff with Convenience Attacks against User Account Passwords Dictionary, Brute-Force & Hybrid Attacks Pre-Computed Hashes Password Complexity Is a Function of Length, size of the symbol set, and ordering - Thus, assuming a random ordering, for each additional character in a password, cracking becomes exponentially harder Malware & Phishing Scams:  Malware & Phishing Scams Mass-Mailing Worms Arrive as email attachments Generally can’t be activated unless you open an infected attachment Could be embedded in HTML messages Phishing Scams Try very hard to look legitimate International Domain Name spoofing doesn’t affect IE Latest scams direct you to a phony web site to enter personal information - or else! Don’t open unexpected attachments! or respond to unsolicited requests! Spyware & Adware:  Spyware & Adware Spyware Tracks Web Browsing Habits Some “adware” is “legitimate” You have to read the fine print! Browser Hijacking You’ll notice if this happens to you! You keep being redirected to the same sites. Be Wary of “Free” Software That includes “security” software! Also some alleged “antispyware” products Think Before You Click! Web links, software downloads, etc. Top 10 Security Measures:  Top 10 Security Measures Patch Microsoft Windows Automatically New patches 2nd Tuesday of each month Use BigFix & Windows Automatic Updates Use Strong Passwords (even better, pass phrases) for All User Accounts Use and Properly Maintain Good Antivirus Software Use a Firewall, such as Windows XP’s Built-in Software Firewall Don’t Open Suspicious Email Attachments or Respond to Suspicious Requests Top 10 Security Measures:  Top 10 Security Measures Disable Windows File & Printer Sharing So long as you’re not using these services Disable in Local Area Connection Properties Disable Unneeded User Accounts Don’t Use Automatic Logon (off by default) Less likely to forget your password!;en-us;315231 Use the Screen Lock When You Step Away & Shut Down When Gone for Over 6 Hours If Possible, Don’t Use Internet Explorer: Try Questions? Research Tools:  Questions? Research Tools Malware Research & Troubleshooting: Web 2.0:  Web 2.0 What is Web 2.0:  What is Web 2.0 “…transition of the web from a collection of websites to a full-fledged computing platform….web 2.0 services are expected to replace desktop computing applications for many puposes” So sayeth Wikipedia Interactivity:  Interactivity Web 1.0 Surf the web Click to get results Send email Web 2.0 Human interaction in the digital space Conversations taking place Interpersonal networking Personalization and individualism Ability to create, distribute and receive web content Ability to participate – not just watch from a distance RSS:  RSS RSS = Really Simple Syndication. Dave Winer is credited with being one of the key developers behind the concept Does two things: You can subscribe to other websites that have RSS feeds (syndication) Create content in one place, but display it in another place This content can be text, photos, mp3 files, video files, etc… RSS:  RSS With RSS Without RSS RSS:  RSS RSS Aggregator:  RSS Aggregator AKA: News aggregator, RSS Reader, Feed Reader, Fee Aggregator, News Reader. An RSS feed is a page of XML code that lays out the content to be distributed for the RSS aggregator. Examples: Newsgator,, My Yahoo, Yahoo Email, Google’s Gmail, Firefox, AmphetaDesk….etc. Huge list of others at RSS Aggregator:  RSS Aggregator Blogs:  Blogs AKA web log Entries posted on a regular basis New entries on top Has an RSS feed Differences between blogs site and websites: Easy to create new pages Templates automatically add posts in proper places Allows searching by title, date, category, author, etc Comments on posts Blogs:  Blogs Blogs:  Blogs What can you do with Blogs? Provide ongoing updates within a team (think of the possibilities in a team or agile programming environment) Provide updates about your organization or department Provide updates to friend and families. Disadvantage? You better keep it up or remove it, because an out of date site screams that you are not on top of things. Blog Resources:  Blog Resources Free Blogging tools: – Many more… Tagging, or Folksonomies:  Tagging, or Folksonomies Categorizing the web Assign freely chosen keywords They “tag” the item Browsable and searchable Web 2.0 uses tagging Tagging, or Folksonomies:  Tagging, or Folksonomies Flickr Digital photo sharing website Photos grouped by submitter, tags, and groups Searching Commenting on each photo RSS of photo feeds – user and tags Applications Staff Event or Business function photos Personal Albums to share with friends & family Supplement to Blog updates Tagging, or Folksonomies:  Tagging, or Folksonomies Tagging, or Folksonomies:  Tagging, or Folksonomies Tagging, or Folksonomies:  Tagging, or Folksonomies Bookmark Managers AKA Social Bookmarking IE favorites generally tied to a single PC Bookmanagers do the same thing but are accessible via the web,, How it works? Just like marking a favorite/adding a bookmark to a site Add tags, description, clipping Others can add comments, ratings Others can subscribe via RSS Searchable Tagging, or Folksonomies:  Tagging, or Folksonomies Tagging, or Folksonomies:  Tagging, or Folksonomies What can you do with Bookmark Managers? Company, Dept, Team or Project bookmarks. Access your own bookmarks anywhere Find an expert and subscribe Search them Allows you to place the RSS feed on another page, Offers reference web links You can see some of my tech bookmarks at WIKI:  WIKI What’s a Wiki? A website that allows anyone to add and edit content Great for collaborative authoring Tracks changes so you can revert back to older page if needed Monitor changes via RSS Searchable Comments can be allowed WIKI:  WIKI WIKI:  WIKI WIKI:  WIKI WIKI Applications Subject Guides Staff Intranet Project management Committee/Taskforce minutes WIKI Resources - free wiki software - another free (hosted) wiki – wikipedia Instant Messanging (IM):  Instant Messanging (IM) Pretty easy – you type, hit enter, they type, hit enter, etc. Chat history is tracked Real time communication PCs, cell phones, PDAs all have IM Individual Clients include: AOL AIM, MSN Messenger, Yahoo! Messenger, IRC, ICQ, Jabber, GTalk,, GroupWise Messenger, etc. Multi-Client services: Trillian, Gaim, Meebo (web-based) Instant Messanger:  Instant Messanger IM Applications Allows for virtual ‘presence’ of a mobile worker. Being ‘virtually’ there as opposed to physically there. Can sometimes allow for more direct communication with less chit chat. Many also support video conferencing and voice services. Voice services much cheaper than using toll lines. Podcasting:  Podcasting Web feed of audio that anyone can subscribe to To listen: Need to be able to play an MP3 (usually Mp3 player) Need an RSS feed reader or one that specializes in RSS enclosures such as iTunes, Juice, IpodderX, FireANT. Application News and marketing briefs Great way to keep up to date while on the road by synchronizing with MP3 player Podcasting:  Podcasting To Create a Podcast Something to say – most important Microphone = can be a Radio Shack cheapie Audacity = free Place to store the podcast –,, etc. = free RSS feed that will distribute podcasts = free (FeedBurner does this) Free, free, free vs Time, Time, Time! VideoCasting:  VideoCasting AKA video blogging, videologging, vlogging, video podcasting, etc Same idea as podcasting, only with video To Watch: Need a video player (Windows Media Player) or some other portable media devide (eg: Archos) Need the RSS feed and a feedreader Even better – a videocasting aggregator such as mefeedia, fireant, and iTunes VideoCasting:  VideoCasting Creating a VideoCast Something to say Camcorder – cheapies for $30… Digital video editing software Windows Movie maker - free Quicktime pro - $30 Adobe Video Collection $1000 Place to store the videocast – = free RSS feed that distributes videocasts = free (feedburner again) Pricey, Takes Time, Is Very Cool. The Digital Home:  The Digital Home HTPC’s & Multimedia Centers:  HTPC’s & Multimedia Centers Home Theater and Media Center PC’s are allowing for centralized distribution of all personal media and content. Eg: Pictures, Video, TV and Audio. It is also allowing for time shifted content and personal video recorder (PVR) functionality by recording to a built in Hard Drive. Many different options exist from specialized PVR’s to commercial and open source media center softwarere. It is the future for home entertainment. Media Centers:  Media Centers The Digital Media Center is designed serve as an entertainment, or content distribution hub. Although the focus right now is for the home user, the idea of centralized digital content distribution is just as viable for a business. Since an increasing amount of content is going digital, video, audio, pictures, books, it is important to develop an appropraite infrastructure to manage this distribution. Best practices for network design should be followed in order to ensure there is enough bandwidth to support the demand. Although Bandwidth is getting cheaper, don’t underestimate the cost or the bandwidth required! HTPC & Media Center References:  HTPC & Media Center References MS Windows Media Center Media Portal – Free Opensource PVR and HTPC MythTV – Free Opensource Linux PVR and HTPC BeyondTV – Another commercial PVR/MC Set top Media Distribution device Various Articles HDMI ( :  HDMI ( High Definition Multimedia Interface (HDMI) was developed to meet the explosive demand for high-definition video and audio. HDMI was originally developed by Silicon Image, but is now in the hands of the HDMI Founders Group. HDMI is a 5Gbps serial, point-to-point interface that carries both digital video and digital audio data. Note that S-Video, Component Video and DVI only deliver the video signal. HDMI supports two-way control communication via CEC (Consumer Electronics Control) allowing devices to communicate even without a remote control. For example, the TV could, in theory, automatically notify the DVD player that it is a 16:9 aspect ratio display, removing that step from the setup. HDMI to HDMI HDMI to DVI HDTV References:  HDTV References Compressing Data:  Compressing Data Under Sounds and Audio Devices in the control panel you can select the compression technologies supported. CODEC refers to Coder/DECoder and can be either lossless or lossy compression. More codecs can be retrieved from MPEG Data Compression Standard:  MPEG Data Compression Standard MPEG (Motion/Moving Picture Experts Group) Stores full motion video and sound Tracks movement from one frame to the next and only stores what changes, rather than compressing individual frames A type of lossy compression (Up to 100:1 for full motion video (30fps) Current MPEG Standards:  Current MPEG Standards MPEG-1 Used in business and home applications to compress images (EG. VCD) MPEG-1 Level 3 (1:12 to 1:24) Best known for audio compression (Digital Audio Extraction Audio) MPEG-2 Used to compress video films (EG. DVD) 720x480, HDTV: 1280x720(720p), 1920x1080 (1080p) MPEG-4 Used for video transmissions over the Internet. Compression:  Compression There is a huge choice when it comes to choosing an audio format - Mp3, Mp4 (AAC), WMA, Wave and Ogg Vorbis, which one is best? It all depends upon your needs: Lossless (get exactly the same as an Audio CD). By default an audio CD is stored as a WAV file, however encoders such as Windows Media (WMA), Monkeys Audio (APE) and FLAC compress without loosing any audio quality; think of it as Zip for audio. Compressed Audio. Audio can be squashed, resulting in a file size much smaller than the original, although this is at the expense of audio quality, bits get lost unless it is compressed in a Lossy audio format Mp3, it the most popular by far. Audio Formats:  Audio Formats MIDI (musical instrument digital interface) Dictate a specific number of sound samples and quality. Specifies pitch, length and volume Have a .mid extension Use data compression due to size of files Used to store most game music Audio Formats:  Audio Formats WAV files (.wav) The most basic of all audio formats and stored uncompressed in its native form (PCM) When an Audio CD is converted to a wave file the resulting wave file is 16 Bit, Stereo with a sample frequency of 44.1Khz, this gives 172K bytes per second of audio data, or 10MBs per minute. Wave files can use CODECs (stands for COmpression DECompression) to be compressed depending upon what CODECs are installed. ADPCM is one simple form of compression, it takes a 16bit value and creates a 4 bit value by calculating the difference between points, so the compression is roughly 4:1. There are even Mp3 CODECs where a wave file can be saved as a Wave/Mp3 file. Avoid these types of files, as they create confusion if you are after a Mp3 file then save it as a proper Mp3 file. Audio Formats:  Audio Formats Advance Audio Coding (.aac or .mp4) Advanced Audio Compression (AAC) has been around for many years and was designed by Dolby & partners. It is more advanced than mp3 and has found popularity through mp4. Apple uses AAC with its online music store stored as m4a files, although protected A refreshing addition to AAC is HE-AAC, uses similar tricks to mp3pro with spectral band replication to enhance lower bitrate encodings (less than 100 Kbps), although a special HE aware decoder is required. AAC has some advanced features, such as 48 audio channels and embedded data streams. Another use of AAC is with Mpeg-2 (home cinema). Since AAC Dolby has introduced updated AC2 and AC3 standards. Audio Formats:  Audio Formats MP3 A method to compress audio files that uses MPEG 1 level 3 Sound quality is dependant on the encoder used. The best are the Lame Encoder and MP3Pro. Can reduce sound files as low as a 1:24 ratio while still sounding similar to the original by removing frequences the human ear cannot hear Usually measure in terms of the bits/s eg: 192Kbps, 160Kbps, 128Kbps. While it's compression routines are not the best, mp3 really wins out in it's compatibility with computers & players. Mp3 is the current number #1 audio standard, when encoding to mp3 the Lame encoder is recommended using one of the ALT Presets. Audio Formats:  Audio Formats MP4 Successor to mp3 mp4 is basically a container storing many sub-formats The main audio format would be Advanced Audio Compression (AAC). Adding ID tags to mp4 seems to have standardized on the Apple iTunes format. Files ending in .m4a are audio content only, .mp4 can contain both audio and video. See also AAC Audio Formats:  Audio Formats Windows Media Audio (.wma) Microsoft's effort, more advanced compression to mp3 especially at lower bitrates. WMA v9 added 2 pass VBR, and three new additions to the codec - WMA Lossless, WMA Pro and WMA Voice. Where as a normal WMA v9 file will play fine in a portable player, currently no portable players will play any of the new additions. Audio Formats:  Audio Formats Ogg Vorbis (.ogg) Ogg Vorbis is a fully Open, non-proprietary, patent-and-royalty-free, general-purpose compressed audio format for high quality (44.1-48.0kHz, 16+ bit, polyphonic) audio and music at fixed and variable bit rates from 16 to 128 kbps/channel. Ogg Vorbis is a popular free (as in free from patents) encoder, often thought of as having a higher quality than Mp3 - most players support Ogg through a plug-in. Ogg supports full ID Tagging where track information (Artist etc) is imbedded within the music file. Ogg support is just appearing on portable players. Audio Formats:  Audio Formats Monkeys Audio Monkeys Audio is a lossless compressor. When a monkeys audio file is played the resulting rendition is exactly the same (quality wise) as the original. Unlike Mp3 and other lossy compression methods, which throw away sound information in the name of higher compression rates. The downside to Monkeys approach is that compression ratios will only be 4:1 at best. Monkeys Audio uses the flexible APE tagging system to imbed track information (Artist etc) within the music file Audio Formats:  Audio Formats Musepack Thought to be based on mp2, musepack, or mpc, or MPEGplus as it is known is apparently a superior lossy encoding. Musepack fills the space between lossless and encoders designed for lower bit rates such as mp3 or Ogg. In the 192Kbps range and above, MPC is extremely good. Audio Formats:  Audio Formats Which Audio Format should you choose depends on your needs: If you want lossless, then Monkeys Audio (APE) or FLAC are good formats. However you need plugins for your media player. Of course if you are using windows media player then Windows Media Audio (WMA) is also a good option. (For IPOD/Itunes users I believe there is also an AAC lossless format using the Applie Lossless Encoder) If you want to go with the flow choose Mp3, it the most popular by far. Mp3 is the undisputed king. Althoug its compression routines are not the best, mp3 really wins out in it's compatibility with computers & players. Many media players will convert to and from MP3 for you, but a good stand alone mp3 codec is the Lame ( encoder If you are using limited memory on a portable mp3 player (64Kbps - 96Kbps) Windows Media Audio (WMA) is a good choice. Audio Formats:  Audio Formats Best Audio Format (cont.) If your portable mp3 player has more room such as the iPod try mp4, or Ogg Vorbis Want the highest quality lossy? (160Kbps - 320Kbps) Musepack ( is the best sounding lossy, although PC support only. A good public all rounder (80Kbps - 160Kbps) is Ogg Vorbis, but check the compatibility if transferring to a portable player. Audio Formats:  Audio Formats Refer to for information on audio formats Video Compression:  Video Compression Lossless compression Compression that doesn't sacrifice any video or audio quality, no data is lost. Very high quality playback, but not great space savings. Video files are still very large. Some popular lossless codecs are HuffYUV, Lossless MJPEG, and Alparysoft. Lossy compression Just like it sounds, lossy compression "loses" some of the original audio and video information. That loss of information is what causes video streams to occasionally look blocky or pixelated. The major benefit of lossy compression is that it reduces video file sizes dramatically. Some popular lossy codecs are MPEG1, MPEG2, MPEG4. Video Compression:  Video Compression Intra-frame vs Inter-frame. Some compression algorithms, such as Motion JPEG (MJPEG) compress each frame individually. This is called intra-frame compression because it only relies on the information within each frame for compression. More advanced compression, such as the MPEG family of codecs rely on the changes in information between frames, counting on the fact that most frames will have something in common with the one right before and right after it. This is called inter-frame compression. In inter-frame compression there will be keyframes spaced throughout the sequence of compressed frames. Keyframes are frames that are compressed like an intra-frame codec, so they don't rely on surrounding frames for decompression. The more keyframes that are included in a video stream, the higher the playback quality tends to be, but they also increase file size significantly. Conclusion!:  Conclusion! Software Developers:  Software Developers So what is the potential for software developers in all these applications and services? Slide133:  References & Web Sites Refer to my bookmarks at http;//

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