Wired and Wireless Networks

One wired mode of connection is transmission media which uses a standard network called an ethernet cable.

Twisted pair copper- lightweight, inexpensive and can be easily installed. Copper coaxial cable - high bandwidth, transmits quickly along large distances, low interference

Copper cables break quite easily Copper cables are affected by electromagnetic interference

Wi-Fi - wireless connection to the internet. WAPs - A wireless transmitter receives data from a network via a physical connection. It then sends these through a physical connection. Bluetooth - A radio wave tech designed to communicate in distances up to 10 meters.

Increased efficiency Accessible and available Cost saving

Criminal activity - An intruder can completely bypass any hardware firewall protective devices. They could then hack the network by planting viruses or denial of service attacks. Bandwidth stealing - by using the internet connection to download games or other software, intruders outside the network can slow down and reduce employee productivity Confidentiality - and intruder can gain access to confidential information

used to protect data in the case of a hacked network. Encryption prevents the data from being understood unless they have the necessary tools. Symmetric encryption - a single key is given from the writer to the recipient Asymmetric encryption - Data encrypted by using a public key. Then encrypted and sent to recipient and recipient decodes.

An Internet Protcol address is a unique address that every separate device in the world has. IPv4 - 8-bit addresses. We have run out of these so we now have IPv6 - this is 128-bits long. arranged in 8 groups of 16-bits all separated by a colon.

Each network interface card has a Media Access Control or MAC address assigned to it by the manufacteurer They are 48- bits long, written as 12 hex digit. Every device has a unique address

Standards let hardware and software interact with many manufacturers/ producers. They are a set of rules for cabling, ethernet, and connectivity. A network standard identifies the speeds used on networks, physical cables used and the wireless tech used.

Application layer- encodes the data being sent so that it will be understandable by the recipient. Adds the appropriate formatting. Transport layer- splits the data into packets and adds packet info such as the packet number telling us the packets order and the total no of packets so they can be reassembled correctly. The Internet layer attaches the IP address of the sender so the recipient will know who sent it. Attaches the address of the host that is sending the data and the destination Link layer - attaches the MAC address of the sender and the recipient, allowing the packet to be directed to specific deviceon a LAN.

TCP - a set of rules that tells us how messages are broken up and reassembled at the destination IP - identifies the location of the device on the internet and routes the packets there.

HyperText Transfer Protocol is used for accessing and receiving web pages in the form of HTML files on the Internet

HyperText Transfer Protocol Secure - This is the same as HTTP but it encrypts the information so that it can not be understood

File Transfer Protocol - A set of rules setting out how to transfer computer files between client and server on a computer network. FTP is based on the client server model.

Post office protocol - A method of receiving emails. POP hold the email until the receiver picks it up. POP creates local copies of emails and deletes the originals from the server.

Internet Messaging Access Protocol - a protocol that stores email messages and allows users to view and change the messages as thought they were stored locally.

Simple Mail Transfer Protocol - is a set of rules of sending e-mail messages between servers. most e-mails systems that send mail over the internet use SMTP to send messages from one server to another.