What is the Internet?
Internet – a massive network of networks
What are packets?
Packets – data is sent over a network in manageable amounts, known as packets
What is an router?
A router is a device that forwards data packets within networks.
What is an TCP/IP?
TCP/IP is the Transmission Control Protocol / Internet Protocol that is used to carry data packets on the Internet.
What is packet switching in Networks?
- In networks, data is both transmitted and received. For example, if you download a web page, an email or a file, the data is broken down into a series of packets; these networks are known as packet-switched networks.
How does a TCP/IP protocol work?
- Data packets are normally less than 128kb and contain details of the destination computer.
- The check code is sent in the data packet and is used to confirm the accuracy of the data sent at the destination computer.
- The IP address for the destination computer contains the host ID and the network ID. This ensures that the packet is only received by the computer requesting the data.
- The data packets for the email can travel via different routes, with the best route determined by the routers based on the destination address.
- The reassembled message is checked for accuracy. If any data packet shows an error, it is rejected and requested again from the sending computer.
What is a Gateway?
Gateway – used to connect one network to another where they have different protocols.
What is a Router?
Router – used to determine an efficient route for data transfer between networks.
How does a gateway work?
- Data that is sent from one network to the other will, therefore, need to be converted from the format that is used on the sending network into the format that is used on the receiving network. This process is carried out by a gateway.
How does a routing work?
- The router transmits package data between the sender and the receiver via a series of nodes or alternative routes. In the diagram above there are many alternative routes that could be taken to transmit data to the web server. The route chosen is shown with a solid line and the alternative routes are shown with dotted lines.
- Routers find the ideal route to take, using sophisticated routing algorithms; each router forwards data based on a routing table to the next router; the routing table contains all the necessary information on the alternative routes available between the sender and receiver.
What is a Uniform resource locator?
Uniform resource locator (URL) refers to the location of a web resource on the Internet or a computer network.
What is an IP Address?
IP address is a number that uniquely identifies every host on an IP network.
What is a Domain name?
- The most commonly used method for accessing a website is to enter its web address or domain name which is more commonly known as a uniform resource locator or URL.
- A website domain name is an easy-to-remember numerical IP address.
What is a Domain name server?
Domain name server translates domain names into their unique IP addresses.
How are Domain names converted into IP addresses?
When we type in a domain name into a web browser, it has to be converted into an IP address so that it can connect to the website. This conversion takes place by using the domain name system (DNS), which keeps details of the unique domain names used and translates them into IP addresses when needed.
What is a feature of domain name systems?
Another service provided by the domain name system is registering new domain names and ensuring that they are unique; it is involved in collecting any fees for domain name registration.
What is an advantage of a domain name?
The main advantage of using domain names is that they are easy to remember in preference to a numerical IP address, where the conversion is carried out automatically by a domain name server. Also, companies can use easy-to-remember domain names that reflect their type of business.
How would you connect to the internet?
- Connect through an Internet service provider (ISP)
- connection could be a ADSL connection ( which comes via the telephone line)
- Connection could be a dedicated fibre optic cable
- Connection could be via 3G or 4G technology - if there is no physical cabling
What is a VPN?
- allows users to send and receive data across public telecommunication networks as if their devices were directly connected to the private network, which drastically reduces the cost.
What does an ISP do?
- ISP supplies a device that provides an outgoing connection from your home network to the service provider.
- It usually has a Ethernet switch with a few ports for wired devices and a wireless access point for wireless connections
What are edge routers?
Edge routers link one network to another
What are subscriber routers?
Subscriber routers are the routers provided to homes and small buisnesses
What are the features of an subscriber routers?
- They are small
- lost cost devices
- two interfaces (one for each network)
- they can be used on internal networks to link network segments
What are enterprise routers?
Enterprise routers connect large buisness and ISP networks to the Internet.
