ITM 300 week 4: - Internet & Telecommunications

Host and Domain Names: A Bit More Complex Than That Load balancing and fault tolerance

(Assigning several computers to a host name (helps) ensure all visits to a popular site like https://www.google.com won't overload 1 computer or website doesn't go down because of 1 computer) load balancing: Distributing computing or network workload across multiple systems to avoid slow performance. fault tolerance: (Systems capable of continuing operation even if a component fails 1 computer can have several host names .• Some domains are further broken down into subdomains—smaller networks or subgroups within larger organization/

cache

A temporary storage space used to speed computing tasks.

Finance Has A Need for Speed and Colocation facility Are most trades made by humans or automation Risk of Colocation facility/automated trading

Colocation facility: Provides a place where the gear from multiple firms can come together and where the peering of Internet traffic can take place. NYSE created a lot data everyday must be transferred to other firms (locations) fast for trading; so many firms have been using colocation facility . Human traders to slow, meaning three in four trades are made without any human intervention. Equipment connecting in colos could be high-speed linesfrom ISPs, telecom lines from large private data centers, or servers hosted in a colo to be closer to high-speed Internet connections .• Less than a decade ago, eighty milliseconds was acceptably lowlatency, but now trading firms are pushing below one millisecond intomicroseconds, and soon, nanoseconds. • This kind of automated trading comes with risks. Systems that run on their own (can move many billions in the blink of an eye, and the action of one system may cascade, triggering actions by others)

If you want to communicate with another computer on the Internet, your computer needs to know the answer to three questions:

What are you looking for (URL) Where is it (IP adress)? And how do we get there (cables)?

telephone wire( 2nd most popular way to connect devices to internet; last mile)

pairs of twisted copper wires or signaling medium that connects a user's telephone to a telecommunications network.

Path Name and File Name (If a Web address has a path and file name)

path: It is the exact location of a page, file, post, or other asset. file: name of file you're looking for. • hypertext markup language: Language that composes Web pages. Connection:• Path and file names are case sensitive—(mistype capital letters and) might get 404 error. • amazon.com/books is considered different from amazon.com/BOOKS.Path Name and File Name

Internet2

research network created consortium by a research, academic, industry, and government firms. High-bandwidth (very fast) next level of internet 100 gigabits per second High-quality video conferencing• High-reliability, high-bandwidth imaging for the medical field• Applications that share huge datasets among researchers

Ping of Death (POD)

type of denial-of-service (DoS) attack that causes computers or services to crash, freeze, or reboot. — sends an oversized and/or malformed packet to another computer.

Summary of types of cable (fiber-optic and coxial/telephone) The answer for the movie (video) 1.What will happen if packets don't make it all the way to their destination? 2.Why light tunnels are used to represent the internet 6. Which of the following telecommunication media does not carry electrical signals? (from quiz Coaxial cable Power line Fiber optic cable Telephone line

Fiber-optic is made of glass; the signal is photon (light) is fastest cable and more expansive, and harder to install. Coaxial cable and telephone/twisted wire is made of copper or aluminum; signal is electrons — Coaxial cable much faster than telephone wire (slower that fiber-optic. Also coxiable cable: - Has shielding/allows cable signals to travel longer distances reduces electrical interference. Limitation: Customers have to share bandwidth w/ neighbors 1.The sends's computer will send these packets against 2. Because the backbone of the internet uses fiber-optic cables as transmission media, which uses light(photon) as transmission signal Fiber Optic Cable

Figure 18.2: Anatomy of a Web Address (in order) (URL) (look at picture) 9.Which of the following is the host server name for https://www.csueastbay.edu/apply/index.html Links to an external site. index edu csueastbay Www

• The URL displayed really says, "Use the Web (http://) to find a host server (internet server) named 'www' in the 'nytimes.com' network (domain), look in the 'tech' (path) directory, and access the 'index.html' file (main web page of company/organization) (Not URLs will have all these elements) Www

IP address (Internet Protocol Address)

IP address: Value ( unique #); identify device connected to the Internet (routing protocol that forwards packets on the internet) IP address can be used to: • Identify a user's physical location .• (Tailor search results. • Customize advertising) • Widely used format IPv4 (version 4) and expressed as 32-bit four numbers (from 0-255), separated by periods: 216.3.128.12 IP address of www.microsoft.com is 207.46.250.119.The IP Address

Wireless 3G, 4G, 5G The bigger the G, ___ and more _____

Mobile phone services usually have a number, followed by a G (generation). The bigger the "G," the faster and more reliable; moving to 5G • Incompatible worldwide 3G or third-generation technologies has beenreplaced by higher-bandwidth 4G (fourth-generation) mobile networks .• The winner in 4G technologies is LTE (long-term evolution). • U.S. average download speeds above 40 Mbps and upload speeds near 20Mbps are now common

Wireless Wireless spectrum ((communication based on bandwidth) Mobile wireless service from cell phone access providers is delivered via ___ • Most mobile cell phone services have to Is bandwidth limited (wireless spectrum). Why?

Mobile wireless service from cell phone access providers is delivered via cell towers. • (Providers require) wireless spectrum (communication based on bandwidth) : Electromagnetic frequencies used for wireless communication. • Most mobile cell phone services have to license spectrum. • High-stakes regional bidding wars whenever governments put news pectrum up for license. • More bandwidth is needed for mobile devices (only have certain amount of frequencies to use for wireless communication) • AT&T now finds that the top 3 percent of its mobile network users gulp up 40 percent of the network's capacity, and network strain will only increase as more people adopt smartphones Have different needs for different usage on internet (phone calls, web browsing podacsts, Youtbute (look at picture) Conventional mobile phones use an estimated 100 MB/month, iPhones560 MB/month, and iPads almost 1 GB/month.Table 18.1: Average Demand Usage by Function

The Internet is Full—We've Run Out of IP Addresses Only long-term solution is to

NAT (network address translation): a service that translates private IP addresses in an internal network to a public IP address. • Helps delay running out of IP addresses but slows down Internet access and is complex and expensive to administer. • expend to more IP addresses (scheme): increases address space from addresses used in current system .• IPv6 is not backward compatible with IPv4 and transition has been very slow. • When IPv6 is deployed, some of the benefits may include potentially improving speed, reliability, and security of the internet.s

Net Neutrality: What's Fair?

Net neutrality: principal that all Internet traffic should be treated equally .• ISPs should not discriminate, slow down access, or charge differentially by user,content, site, platform, application, type of attached equipment, or modes ofcommunication. • Access providers have wanted to offer varying coverage, depending onthe service used and bandwidth consumed .• Internet content providers worry that without strong neutrality rules,ISPs may block content or favor their own offerings above rivals'. • If network providers move away from flat-rate pricing toward usage-based pricing, this may limit innovation.

Internet Service Provider (ISP) (Internet 101: Understanding how the internet works). The internet was designed to be _______and ________

Organization or firm that provides access to the internet. (In order to get internet service, need it get from an internet provider) Ex in California most popular service providers are Xfinity (Comcast) and AT&T •Providers connect to one another, exchanging traffic, so messages can get to another computer. •The internet was designed to be redundant and fault-tolerant—if one network, connecting wire, or server stops working, everything else should keep on running.

key networking technologies: Packet Switching (or datagrams)

Packet switching: method of slicing digital message into parcels Parcel called packet (Delivers data by dividing a message into parts (packets), and these packets are sent along different communication paths and resembled at their destination) (packets can take different routes to the destination). Allows faster, more efficient data transfer.

What Connects the Routers and Computers? What are the 3 types of cable?

Routers are connected wirelessly or by cables. Copper cables (ethernet cable) transmissions sent through via electricity (electrons) - used for connecting a computer in a home. Ex: Connecting TV to network • Fiber-optic line: (on later slide) .• peering: separate ISPs; link their networks and exchange data( to swap traffic on the Internet) • Takes place at neutral sites called Internet exchange points (IXPs). • Some firms have private peering points. Copper cable, fiber-optic line and telephone wire (twisted wire)

Satellite for Wireless (important component) Satellite transponders listen...

Satellite is used to relay signals over very long distances. —(Communications satellite simply a big microwave repeater in the sky) Satellite transponders listen to a particular portion of the electromagnetic spectrum, amplify the incoming signals,and retransmit back to earth . A modern satellite may have 40 transponders, each can handle 80 mbps data transmission and 1,250 digital voice channels of 64 kbps each Diagram: Want to send microwave from 1 side of Earth to another, use 2 salitlle. to really signal in the sky

(Get Secure with https or Prepare to Lose Customers) Secure Sockets Layer (SSL) How get make sure website is secure

Secure Sockets Layer (SSL): security standard that creates an (encrypted link between a Web server and a browser) Websites that use SSL will begin with https (note the 's' at the end). https guarantees the website is secure, if not https web browser(most likely say) website not secure. https websites need to be certified to get https connections Connection: Lock means secure; unlocked means not secure (look at picture)

Satellite Wireless to Reach the Remote Terrestrial wireless GEO (geosynchronous earth orbit)

Terrestrial wireless: provided by earth base stations like cell phone towers. (Possible via satellite. • First residential satellite services were only used for downloads) (GEO Fixed orbit synced to a given point on the rotating earth's surface, but the distance produces a transmission latency of about 1/2 a second in each direction. — travel at roughly 22,000 miles above the earth's surface) (Look at picture Satellite systems show promise in providing high-speed access to underserved parts of the world, but few satellite broadband providers have been successful so far.

Figure 18.1 The Internet Is a Network of Networks

The internet is a network of networks, and these networks are connected (includes all types of networks) Ex: In this diagram, the "state.edu" campus network is connected to other networks of the Internet via two ISPs. - Many local area network (LEN) includes many companies, organizations and community (households) networks. Explanation of picture)(Along the top of the graphic is a local network, which has its own web server. The web server connects on the right, through a Firewall, to the Dorm Users (via Dorm LAN), Class/Office Users (via Office LAN), and Wireless Users. This entire diagram along the top is then connected to the Internet through a section labeled ISP 1 and ISP 2, since they are the providers that make it possible. The Internet is then labeled with example websites (stanford.edu, google.com and whitehouse/gov), along with branching off to a section labeled Local ISP/.

Watching the Packet Path via Traceroute Is it built into all major operating sytems?

Traceroute repeatedly sends a cluster of three packets starting at the first router connected to a computer. •Builds out the route (path) that packets take to their destination (from 1 destination to another) Yes •Windows, Macs, Linux •Several Websites will run it between locations. • Ex: traceroute.org and visualroute.visualware.com •Not all routers and networks are traceroute friendly. •(Neat way to explore how the Internet works) Connection: Like checking a delivery package for delivery; can see if/how it get from Irish Firm to destination Boston Collge

UDP (user datagram protocol): VoIP (voice over Internetprotocol):

UDP (user datagram protocol):replacement for TCP, used when it makes sense to sacrifice packet quality for delivery speed. It's often used for media streaming. Ex:(Live steaming media application like google hangouts, video games, would cause lag if used TCP; (faster) grab packets as they come and play them, even if they have minor errors. • VoIP (voice over Internet protocol): Transmission technologies that enable voice communications (phone calls) to take place over the Internet & private packet-switched networks.

(The URL: "What are you looking for". URL (Web Address) Protocol Hypertext transfer protocol (http): SMTP FTP

URL (uniform resource locator): What you're looking for. Identifies resources on the internet along w/ the application protocol needed to retrieve it. Often used interchangeably w/ "Web address - Tool to access internet or web pages like searching for (domain name or IP addresses) — (URLs are made up of multiple parts, including a protocol and domain name. These parts tell a web browser how and where to find a resource). protocol: Set of rules of communication (on internet) Enables communication (by defining the format of data) and rules for exchange. hypertext transfer protocol (http): Application transfer protocol that allows Web browsers and Web servers to communicate with each other. - Connection: Most popular protocol; protocol you want to use to access any website Other popular protocols SMTP, or simple mail transfer protocol, which is a server to hold e-mail. FTP: File transfer protocol that is used to copy files from one computer to another.

But What If the DNS Gets Hacked?

Usually happens when system security updates are not installed correctly or in a timely manner. • Cache poisoning exploits a hole in DNS software, redirecting users to sites they didn't request. (Hacker will provide fake IP address and website, so u can't get domain name or go to the website you want. Usually users redirected to fake sites to steal passwords and credit card data (steal $ from you))

Cable Broadband (last mile way to connect devices to internet) Is coaxialable the samething as enternet cable

Around 90% of US homes have cable provider, can use thick copper wire to offer broadband access. coaxial cable: Insulated copper cable (used by TV providers) - Has shielding/allows cable signals to travel longer distances reduces electrical interference. Limitation: Customers have to share bandwidth w/ neighbors Fiber Optic Cable: Cable that uses light (photon) guided through thin glass tubes , instead of electrical signals (electron) copper or telephone cable , to transmit data. It is very fast but also expensive. No; coxial cable is a type of ethernet cable Rolling out new technology called DOCSIS 3.1 that can support multigigabit download speeds. • Creating so-called fiber-copper hybrids that run high-speed fiber-optic lines into neighborhoods, then use lower-cost but still relatively high-speed, copper infrastructure over short distances to homes

Bluetooth What does Pans stand for Links up to _ devices within a __-meter area.

Bluetooth: A standard for short-range wireless connectivity, typically meant to eliminate cabling used for things like speakers,printers, cameras, and other devices. .Small personal area networks stadnard(PANs). Links up to 8 devices within a 10-meter area. Connect computer to printer, keyboards to PC, cell phone to earpieces.

Fiber to the Home (FTTH) (Fiber: A light Glass Pise to Your Doorstep: Solution to last mile) They are the ____ last mile tech Limitation:

Broadband service provided via light-transmitting fiber-optic cables (solution for home network connection) Fastest last-mile tech and works easily over long distances. • Firms that use this service include: • Verizon Fios, CenturyLink, AT&T,Google • Limitation—need to build fiber infrastructure (from scratch) and cost is enormous.

Fiber Optic Cable (tconnect devices to internet; last mile)

Cable that uses light (photon) guided through thin glass tubes , instead of electrical signals (electron) , to transmit data. It is very fast but also expensive. • Carry lots of data over long distances . Is faster, lighter, and more durable than wire media. Is difficult to work with, expensive, and harder to install. glass lined cables that transmit light ( fastest line for internet, light faster than electricity) Data are transformed into pulses of light Consists of strands of clear glass fiber, each thethickness of a human hair, which are bound into cables.

Figure 18.4: Finding an IP address

(Domain name must be converted to IP address Root name server convert domain IP address, if not found point to commercial name server (.com), if not will further ask if you're looking for yahoo.com (yahoo.com nameserver) So if it can't find the IP will get to next phase) (Your computer doesn't know where to find that address, but when your computer connected to the network, it learned where to find a service on the network called a DNS resolver. The DNS resolver can look up host/domain name combinations to find the matching IP address using the "phone book" that is the DNS. The resolver doesn't know everything, but it does know where to start a lookup that will eventually give you the address you're looking for. If this is the first time anyone on that network has tried to find "www.yahoo.com," the resolver will contact one of thirteen identical root nameservers. The root acts as a lookup starting place. It can point you to a nameserver for the next level, which would be one of the ".com" nameservers in our example. The ".com" nameserver can then find one of the yahoo.com nameservers. The yahoo.com nameserver can respond to the resolver with the IP address for www.yahoo.com, and the resolver passes that information back to your computer. Once your computer knows Yahoo!'s IP address, it's then ready to communicate directly with www.yahoo.com.)

5G: A Slow Rollout to a Faster Wireless Network - 1&2 What's the key to move from 4G to 5G

(Faster, more reliable, and have higher overall capacity than 4G networks. Gigabit-plus speeds of 5g rival to home television and data packages offered by cable firms .• Infrastructure and devices need to be upgraded. • Transmission points are much smaller than the massive towers used to support4G, allowing 5G access to be built in places such as on top of traffic lights. • Complications include: • Operating expenses costlier than previously expected. • Many 5G firms in the U.S. planned to use technology from the Chinese firm, Huawei, which was banned by the Trump Administration. • Devices designed to work with certain carriers don't work with others) (What's the key to move from 4G to 5G? Software; have to update it Benefit; 5G moves what done on hardware to software can be upgraded without swapping hardware (chips) 5G may be a catalyst for all sorts of applications, including self-driving automobiles, emergency response communication,telemedicine, "bespoke" network offerings for VR, AR, and high-speed game streaming, and smart city sensors for things liketraffic routing, air and water monitoring, and community safety)

TCP/IP, or the Internet protocol suite TCP (transmission control protocol): The Internets Secret Sauce TCP slides up the ____ into smaller ___ of _____ called Routers Review of IP

(TCP mainly for packets, slices up web page into packets (smaller chunk of date) IP mainly responsible for delivery of packets, and TCP resembles data which at final destination) TCP (transmission control protocol): Works at both ends (start and endpoint of trip; your computer and destination computer you're communicating with) of internet communication to make sure perfect copy of a message is sent. • TCP slices up the Web page into smaller chunks of data called packets (or datagrams): Unit of data forwarded by a network. All internet transmissions are divided into packets . • IP (internet protocol): Routing protocol that forwards packets on the internet (to their final destination) Routers: computing device that connects networks and exchanges data between them.TCP/IP: - (Connects w/ other routers and other computers using IP) Every computer on the Internet is connected to a router, and all routers are connected to at least one (and usually more than one) other router, linking up the networks that make up the Internet. Destination computer: a computer that receives incoming network connections

How many groups and bits, and total bits for IP adress What's the range of IP Address Can you tell me in total how many different IP addresses are available on the Internet? Is this IP address, 14.635.235.63, valid? (only look at bold

An IP address includes four groups of bits and each group has 8 bits; 32 bits in total. (from chapter 1: In this equation, 2 is known as base number, which indicates how many different numbers exist in the numbering system 0 and 1) So why is the range of IP addresses in decimal number is: 0.0.0.0—255.255.255.255? The smallest 8 digits decimal number is 00000000=0 (The smallest 8 bits binary number is 00000000 The largest 8 digits decimal number is 99999999 The largest (possible) 8 bits binary number is 11111111) Convert 11111111 into a decimal number (to figure how # is): (exponent starts 7 (1 to right of 1st number then go down by 1 till get to 0. 11111111=1*2^7+1*2^6+1*2^5+1*2^4+1*2^3+1*2^2+1*2^1+1*2^0 =1*2^8-1=256-1=255 So the range of IP addresses in decimal number is: 0.0.0.0—255.255.255.255 In total how many different IP addresses are available on the Internet? 4 combinations of 0 to 255 gives you a little over 4 billion possible IP addresses Is this IP address, 14.635.235.63, valid? No 635 > 255.

Domain Name Service (DNS): The Internets Phone Book Nameservers Connection: • Like big, hierarchical set of phone books capable of finding Web and email servers and more.

DNS servers eliminate the need for humans to memorize IP addresses such as 192.168.1.1 Internet directory: internet directory service allows devices/services to be named and found) (look at picture) — Distributed database that looks up host and domain names and returns IP address for them (Converts IP addresses to domain name or visa verse) • These "phone books" are called nameservers—they work together to create the DNS, they can get you anywhere you need to go online. (Once the lookup has taken place, that IP address can be saved in a holding space called a cache, to speed future lookups)

DSL: Phone Company Copper Phone line Limiation: lacks the _____ used by cable

Digital subscriber line (DSL):Broadband technology that uses wires of a local telephone network .• Speeds vary depending on the tech deployed. • Limitation—uses standard copper telephone wiring that lacks the shielding used by cable Broadband over power line (BPL): has been available for years. • Deployments are few cause considered pricier and less practical than alternatives

Summary of URL, IP address, and DNS

Domain Name System (DNS) is the phonebook of the Internet. Humans access info online through domain names, like nytimes.com or espn.com. Web browsers interact through Internet Protocol (IP) addresses. DNS translates domain names to IP addresses so browsers can load Internet resources. — Each device connected to the Internet has a unique IP address which other machines use to find the device. DNS servers eliminate the need for humans to memorize IP addresses such as 192.168.1.1 (in IPv4), or more complex newer alphanumeric IP addresses such as 2400:cb00:2048:1::c629:d7a2 (in IPv6). — When a user wants to load a webpage, a translation must occur between what a user types into their web browser (example.com) and the machine-friendly address necessary to locate the example.com webpage.

Host and Domain Names

Domain name: name of the network you're trying to connect to (usually represents an organization). • The host is the computer you're looking for on that network; example www. Connection: Many domains have lots of different hosts. • Google's main website is served from host named "www", but runs other hostsincluding those named (sub domain) "finance", "calendar", and "drive", among many others. • Host and domains are not case-sensitive. • You can use a combination of upper and lower case letters and still get to your destination.

I want My Own Domain To stake your domain name claim in cyberspace, a firm called a domain name registrar can be used

Don't buy domain name, but register it (usually yearly fee) • Web hosting services: A firm that provides hardware and servers to run the websites of others. • ICANN (Internet Corporation for Assigning Names and Numbers):Nonprofit governance and standards-setting body that approves registrars throughout the world

Last Mile (problem: Faster Speed, Broader Access Internet Backbone Amdahl's LawL Broadband and bandwith

Internet backbone (fiber-optic lines): High-speed data lines that interconnect and collectively form the core of the Internet. • Amdahl's Law: System's speed determined by its slowest component. • last mile (cable): technologies (like PC) that connect end users to the Internet (last and slowest part) .The last-mile problem: connection usually the slowest part of the network .• broadband: High-speed Internet connections .• bandwidth: Network transmission speeds that are expressed in some form of bits per second (bps)

WiFi (wireless fidelity) and other Hotsports To connect to the Internet, a device need to be ____....

Wireless tech for local area (like CSUEB, home, hotel) networking devices. —Allows PCs and other electronic connect to the internet without wires. To connect to the Internet, a device needs to be within range of a base station or hotspot .• Wi-Fi base stations used in the home usually bought by end users, then connected to a cable, DSL, or fiber provider. • Wi-Fi equipped mobile devices also offer an opportunity to act as a personal hotspot. • Connects to the Internet via the cell network .• Allow nearby devices to also connect to the Internet

Wireless technology Wireless transmission based on Microwave systems widely used for What to communication the problem

Wireless transmission based on radio signals of various frequencies. Microwave systems widely used for high-volume, long-distance, point-to-point communication. Earth not flat, have to have radio station (satellite) in the sky to relay microwave signals Microwave signals only go straight line Microwave signals follow a straight line and do not bend with the curvature of the earth Communication satellites solve the problem by serving as relay stations Transmission stations are positioned about 37 miles apart. Electromagnetic waves: look different because have different wavelengths and frequency. radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma rays,

Summary of wireless tech Wireless wide area network (WWAN): Wireless local area network: Wireless short distance:

Wireless wide area network(WWAN): Cellphone tech Wireless local area network(WLAN): WiFi Wireless short distance: bluetooth.

Network

a group of two or more computer systems linked together