Structure of the Internet Flashcards
What is a tier 1 network?
Backbone cables connecting continents, where then large telecom companies connect together.
What is an Internet Exchange Point (IXP)?
Physical infrastructures where ISPs connect
What is a Point of Presence (POP)?
Places ISPs communicate with users
What is a tier 2 network?
ISPs that buy Internet transit from other providers to reach parties on the global internet.
What is Packet switching?
Sending of packets across a network where other similar communications are happening.
What does a router do?
Reads the destination IP of packets and forwards it to destination on the fastest least congested route.
What are the main components of packets?
- Header
- Source IP
- Destination IP
- Other metadata
- Payload
- Trailer with Cyclical Redundancy Check (optional)
What is a gateway?
A device that connects networks using different protocols
What is a router?
A device that connects 2 or more different networks
When should you use a router and when should you use a gateway?
Router: When networks have the same protocol
Gateway: When networks have different protocols
How is routing achieved?
A routing table is used to store the location of other network devices and the fastest route to them and is updated as needed
What is a uniform resource locator (URL)?
Full addresses for internet resources
What is a fully qualified domain name (FQDN)?
A domain name that includes host server name (i.e. www, mail, ftp)
What is an IP address?
A numerical label assigned to a device on a network.
How are domain names organised
Using internet registrars which are organisations that manage allocation and registration of IP addresses, domain names and other resources that must be unique.
What is the function of the domain service and it’s reliance on the domain Name Server (DNS)?
DNS is the service for translating between Domain Names and IP addresses provided by the DNS.
DNS servers form a distributed database
Why are Internet registries important?
They mange allocation and registration of IP addresses and domain names. This keeps things organised and therefore no collisions keeping the internet running smoothly.
