systems and tech exam 5

… is an interconnected/interrelated system

network

the utility of a network approximately equals the square of the number of users

Metcalfe’s Law (network effects)

Amount of data that can be transferred from one point to another in a certain time period

bandwidth

Network transmission speeds, typically expressed in some form of bits per second (bps).

bandwidth

Network transmission speeds, typically expressed in some form of bits per second (bps)

bandwidth

Loss of power in a signal as it travels from the sending device to the receiving device

attenuation

computers connected at a single physical site

LAN (local area network)

computers connected between two or more separated sites

wide area network (WAN)

network of networks

the internets and internets

Organization or firm that provides access to the Internet

Internet service provider (ISP)

ISPs connect to one another, exchanging …

traffic

Ensure that … can get to any other computer that’s online and willing to communicate

messages

They also build and maintain the infrastructure that makes connection possible

Internet service providor

The … is a network of networks, and these networks are connected together

internet

Enables communication by defining the format of data and rules for exchange

protocol

there are 4 protocols

Hypertext transfer protocol (HTTP)

SMTP

FTP

TCP/IP

Application transfer protocol that allows Web browsers and Web servers to communicate with each other

Hypertext transfer protocol (HTTP)

Simple mail transfer protocol; for e-mail

SMTP

File transfer protocol, used to copy files from one computer to another

FTP

the Internet protocol suite

TCP/IP

identifies Internet resources and their associated protocol

-But we usually just call it a “Web address”

uniform resource locator (URL)

Represents an organization

domain name

Public services offered by that organization.

-Usually not just a single computer

Hosts

Distributing a computing or networking workload across multiple systems in order to avoid congestion and slow performance

Load balancing

Systems that are capable of continuing operation even if a component fails

Fault tolerance

Pay a registrar for the right to use that name, with the right renewable over time

Domain name registration

pay a registrar for the right to use that name, with the right renewable over time

Web hosting

A nonprofit governance and standards-setting body that accredits registrars throughout the world

Internet Corporation for Assigning Names and Numbers (ICANN)

registering a domain name to profit from someone else’s organization name or trademark

Cybersquatting

Internet directory service that allows devices and services to be named and discoverable on the Internet

Domain Name Services

It is a … that looks up host and domain names and returns the actual IP address for them

distribute database

Find Web servers, e-mail servers, and more

Nameservers

Temporary storage space used to speed computing tasks

Cache

Message, broken into …, moves across the Internet, passing through networks owned by telecom providers known as …

packets and carriers

Message, broken into …, moves across the Internet, passing through networks owned by telecom providers known as carriers

packets

-Carriers freely exchange traffic among themselves without paying access fees.

-Takes place at neutral sites called Internet exchange points (IXPs)

Peering agreements

Provides a place where:

•Gear from multiple firms can come together.

•Peering of Internet traffic can take place

Colocation Facility (Colo)

-High-speed lines from ISPs.

-Telecom lines from large private data centers.

-Servers are hosted in a colo to be closer to high-speed Internet connections.

Equipment connecting in colos

•Standard circuit switching of POTS (Plain Old Telephone Service)

•Started with a person physically connecting callers.

• The switching process was mechanized and eventually digitized, but still connected two ends

Original switching

Internet switching

… – Now, all data is split into packets, routed individually over the Internet, and reassembled at the receiving end

packet switching

…formal rules for communications

Protocols

-Transmission Control Protocol/Internet Protocol

-The standard protocol suite for the Internet

TCP/IP

•Internet telephony, replaces public-switched service

•Examples: Vonage, Ooma

Voice Over IP (VOIP)

Works at both ends of internet communication to ensure a perfect copy of a message is sent

TCP (Transmission control protocol)

Unit of data forwarded by a network.

- All Internet transmissions are divided into packets. More in a few minutes.

packets or datagrams

Routing protocol that is in charge of forwarding packets on the internet

IP (Internet protocol)

Computing device that connects networks and exchanges data between them

Routers

• Identifies a particular device on the public Internet.

• Assigned by ICANN (Internet Corporation for Assigned Names and Numbers).

• Your ISP or large company gets a public IP address

Public IP addresses

• Identifies a device on a private network, usually a LAN.

• Assignment controlled within the LAN

Private IP addresses

… standard uses 4 8-bit numbers (32b total)

• ~4.3 billion addresses = 4.3x109

IPv4

… is 128-bit

• 3.4×1038 addresses available

• 5×1028 addresses for every person on the planet

IPv6

… address = 6B, 3B manufacturer ID, 3B serial #

• Media Access Control

• Tied to the network interface card (NIC)

• Uniquely identifies each computer

MAC

Refers to the technologies that constitute the end user connections to the Internet, which is typically the slowest connection

the last mile

High-speed data lines that interconnect and collectively form the core of the Internet

internet backbone

…A system’s speed is determined by its slowest component

Amdahl’s Law

If a chain is only as strong as its weakest link, your connection is only as fast as the … network link

-potential problem

slowest

The … is how we make the connection to the Internet or other networks

media

Some … connects us over long distances, some over short distances

media

Wired and … are both available – even in our classrooms

wireless

Uses thick copper wire to offer … access

cable broadband

…Insulated copper cable used by television providers

Coaxial cable

Has shielding that reduces electrical interference

-Allows cable signals to travel longer distances without degrading

and with less chance of interference

coaxial cable

Requires customers to share bandwidth with neighbors

Limitation

Broadband technology that uses the wires of a local telephone network

Digital Subscriber Line (DSL)

Speeds vary depending on the technology …

depolyed

uses standard copper telephone wiring that lacks the shielding used by cable

limitations

Broadband over power line technology has been available for years.

-New deployments are few because it is considered to be … and less practical than alternatives

pricier

Broadband service provided via light-transmitting fiber-optic cables

fiber to the home

… last-mile technology that works easily over long distances

fastest

-Need to build fiber infrastructure from scratch

-The cost of building it is enormous

Limitations

Mobile … service from cell phone access providers is delivered via cell towers

wireless

providers require a …

wireless spectrum

Frequencies used for wireless communication. Most mobile cell phone services have to license spectrum. Some technologies (such as Wi-Fi) use unlicensed public spectrum.

wireless spectrum

Parts of the developing world have bypassed wired connections and gone directly to …

wireless

-Requires infrastructure replacement.

-Smaller transmission points with more limited range.

5G

-OneWeb

-SpaceX’s Starlink

-Amazon

Satellite wireless

… Wireless local-area networking devices

wifi

Wi-fi stands for …

wireless fidelity

To connect to the Internet, a device needs to be within range of a …

base station or hotspot

Wi-Fi equipped mobile devices also offer an opportunity to act as a…

personal hotspot

a standard for short-range wireless connectivity, typically meant to eliminate cabling used for things like speakers, printers, cameras, etc…

-•When it was first developed, it was a solution without a problem

bluetooth

The principle that all Internet traffic should be treated the same

net neutrality

Access providers have wanted to offer varying coverage, depending on the service used and …consumed.

bandwidth

Internet content providers worry that without strong …, ISPs may block content or favor their own offerings above riva

neutrality rules

If network providers move away from flat-rate pricing toward usage-based pricing, this may limit …

innovation and access