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Intro to Networking

Philip AshmanAsst. Prof. Okanagan College

Dept of Network & Telecommunications Engineering Technologies

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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!

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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

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• 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

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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-7 Layer Model

DOD 3-Layer Model Simplified 4/5-layer Model

7 Application

Application Application6 Presentation

5 Session

4 TransportProtocol

Transport

3 Network Newtork

2 Data Local Network

(LAN)

Data

1 Physical Physical

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.

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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…

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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

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• Two main categories:

1.Guided• Twisted-Pair cables:

Unshielded Twisted-Pair (UTP) cables Shielded Twisted-Pair (STP) cables

• Coaxial cables• Fiber-optic cables

2.UnGuided• Wireless transmission, e.g. radio, microwave, infrared,

sound, sonar

Transmission Media

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• 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

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• 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

MetalInsulator

Unshielded Twisted-Pair (UTP)

4 PairsPlastic Cover

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• 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)

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• EIA classifies UTP cables according to the quality Categories 1,2,4 used to exist, but you can’t buy them any more:

Category 3At 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 6More twists than Cat 5, up to 1 Gbps and uses 23 Gauge wire. Also rated up to 10Gbps for 35m.

Categories of UTP Cables

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• 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

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• Light travels at 3108 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

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• 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

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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)

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Fiber Optic CablesAdvantages and Disadvantages

– Noise resistance External light is blocked by outer jacket

– Less signal attenuationA signal can run for miles without regeneration (currently, the lowest measured loss is about ~4% or 0.16dB per km)

– Higher bandwidthCurrently, limits on data rates come from the signal generation/reception technology, not the fiber itself

– CostOptical fibers are more expensive than copper

– Installation/maintenanceAny crack in the core will degrade the signal, and all connections must be perfectly aligned

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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.)

Protocol Release Date Op. Frequency Data Rate (Typ) Data Rate (Max) Range (Indoor)

Legacy 1997 2.4 -2.5 GHz 1 Mbit/s 2 Mbit/s  ?

802.11a 1999 5.15-5.35/5.47-5.725/5.725-5.875 GHz 25 Mbit/s 54 Mbit/s ~50 meters

802.11b 1999 2.4-2.5 GHz 6.5 Mbit/s 11 Mbit/s ~100 meters

802.11g 2003 2.4-2.5 GHz 11 Mbit/s 54 Mbit/s ~100 meters

802.11n 2006 (draft) 2.4 GHz or 5 GHz bands 200 Mbit/s 540 Mbit/s ~250 meters

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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.

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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)

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• 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

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• 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)

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• 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: 28T1=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

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The connection is shared by a number of subscribers, hence may raise performance and security problems

Fiber-optic cable

Cable companyCoaxial Cable

TV

PC

Cable Drop

Broadband Cable Network

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• Shaw is also providing an asymmetrical service.• Downstream: max 25 Mbps• Upstream: max 1 Mbps

• Need a special Cable modemEthernet

link to PC

Coaxial link from cable TV

socket

Terayon Cable Modem

Shaw Cable

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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.

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Each connection is shared by a number of subscribers, hence may raise performance and security problems

Fiber-optic cable

Telco company

CopperCable

Local Telco Office

Telco Network

Fiber

optic

Home

Business

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• 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

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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

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• 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

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• 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

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• 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

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• 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

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• 3 basic types?

Bus Topology Ring Topology

Star Topology

Core

Network Topology

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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

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Star Topology

Bus Topology

BNC T-Connector

Coaxial cable

Network Card

Network Topology

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Ring Topology• Every computer serves as

a repeater to boost signals• Uses Token passing to send

data, where only the computerwho gets the token can senddata

• Disadvantages

• Difficult to add computers• More expensive• If one computer fails, whole network fails

T T

T

data

T

data

T

data

T data

T data

T data

T Ack

T Ack

T Ack

TAck T

Topology

Protocol Basics

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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 http://coffer.com/mac_find/ to look up some vendor codes.

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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.

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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.

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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 https://radon.bc.tac.net/cgi-bin/oca2.cgi)

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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.)

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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.

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IP Addressing

• IP addresses consists of 4 “octets” such as: 171.64.20.23

• 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!)

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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 (http://www.arin.net)

• 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.

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DNS

• A name, such as “technologies.okanagan.bc.ca” 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 okanagan.bc.ca 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

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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.

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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 (http://www.warriorsofthe.net/)

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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)

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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.

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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

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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

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What’s the Threat?• Viruses, Hackers and Worms - Oh, My!

– Purists reserve the term “hacker” for ace programmers, not “attackers”

http://catb.org/~esr/jargon/html/H/hacker.html

• “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

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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

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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

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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 http://isc.sans.org/survivalhistory.php

• 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

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So You’re on the Internet…• Go to http://windowsupdate.microsoft.com

– 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)

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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

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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!

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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.

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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

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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!http://support.microsoft.com/default.aspx?scid=kb;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 http://www.mozilla.org/firefox

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Questions? Research Tools

• Malware Research & Troubleshooting:– http://support.microsoft.com/kb/129972

– http://www.google.com

– http://www.sarc.com

– http://www.mcafeesecurity.com/us/security/home.asp

– http://housecall.trendmicro.com/

– http://en.wikipedia.org/wiki/Computer_virus

– http://www.educause.edu/Browse/645?PARENT_ID=741

– http://www.spywareinfo.com/

– http://support.microsoft.com

– http://www.microsoft.com/technet

– http://www.cert.org/

– http://www.cisecurity.org/

Web 2.0

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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

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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

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RSS

• RSS = Really Simple Syndication. Dave Winer is credited with being one of the key developers behind the concept

• Does two things:

1. You can subscribe to other websites that have RSS feeds (syndication)

2. Create content in one place, but display it in another place

• This content can be text, photos, mp3 files, video files, etc…

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RSS

With RSSWithout RSS

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RSS

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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, Bloglines.com, My Yahoo, Yahoo Email, Google’s Gmail, Firefox, AmphetaDesk….etc.Huge list of others at http://en.wikipedia.org/wiki/List_of_news_aggregators

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RSS Aggregator

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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

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Blogs

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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.

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Blog Resources

• Free Blogging tools:

– Blogger.com

– Livejournal.com

– Wordpress.com

– Many more…

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Tagging, or Folksonomies

• Categorizing the web

• Assign freely chosen keywords

• They “tag” the item

• Browsable and searchable

• Web 2.0 uses tagging

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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

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Tagging, or Folksonomies

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Tagging, or Folksonomies

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Tagging, or FolksonomiesBookmark Managers

• AKA Social Bookmarking

– IE favorites generally tied to a single PC

– Bookmanagers do the same thing but are accessible via the web

– Del.icio.us, www.furl.net, www.blinklist.com

• 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

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Tagging, or Folksonomies

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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

– Del.icio.us:

• Allows you to place the RSS feed on another page,

• Offers reference web links

• You can see some of my tech bookmarks at http://del.icio.us/philashman

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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

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WIKI

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WIKI

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WIKI

WIKI Applications

– Subject Guides

– Staff Intranet

– Project management

– Committee/Taskforce minutes

WIKI Resources

– http://www.mediawiki.org/wiki/MediaWiki - free wiki software

– http://pbwiki.com/ - another free (hosted) wiki

– www.wikipedia.org – wikipedia

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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)

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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.

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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

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Podcasting

To Create a Podcast

– Something to say – most important

– Microphone = can be a Radio Shack cheapie

– Audacity = free

– Place to store the podcast – archive.org, ourmedia.com, etc. = free

– RSS feed that will distribute podcasts = free (FeedBurner does this)

– Free, free, free vs Time, Time, Time!

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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

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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 – archive.org = free

– RSS feed that distributes videocasts = free (feedburner again)

– Pricey, Takes Time, Is Very Cool.

The Digital Home

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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.

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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!

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HTPC & Media Center References

MS Windows Media Centerhttp://www.microsoft.com/windowsxp/mediacenter/default.mspx

Media Portal – Free Opensource PVR and HTPC

http://mediaportal.sourceforge.net/

MythTV – Free Opensource Linux PVR and HTPChttp://www.mythtv.org/

BeyondTV – Another commercial PVR/MChttp://www.snapstream.com

Set top Media Distribution devicehttp://www.dlink.com/products/?sec=3&pid=387

Various Articleshttp://www.2cpu.com/articles/113_1.html http://www.htpcnews.com/main.php?id=guides1 http://www.tivo.com/0.0.asp

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HDMI(http://www.hdmi.org)

• 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 HDMIHDMI to DVI

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HDTV References

• http://www.avsforum.com/

• http://www.hdmi.org

• http://www.htguys.com/

• http://www.hdtvmagazine.com/articles/2005/12/lcos.php?page=1

• http://www.hdbeat.com

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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 http://www.afreecodec.com

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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)

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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.

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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.

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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.

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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 (http://www.mp3dev.org/) encoder

– If you are using limited memory on a portable mp3 player (64Kbps - 96Kbps) Windows Media Audio (WMA) is a good choice.

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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 (http://www.musepack.net) 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.

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Audio Formats

• Refer to http://www.dbpoweramp.com/spoons-audio-guide-formats.htm for information on audio formats

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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.

Conclusion!

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Software Developers• So what is the potential for software developers in all these applications and

services?

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References & Web Sites

• Refer to my Del.icio.us bookmarks at http://del.icio.us/philashman