2.06 - The Internet Infrastructure Flashcards
What is the Internet?
The internet is the biggest internetwork in exsistence and has evolved to its current form and is still evolving towards its future form. There is no agreed definition of the Internet’s structure, but there is a hierarchical aspect to it.
What was the initial function of the ISP?
The initial function of an ISP was to give Internet access to an individual or company, and now it is performed by an access ISP
What performs the initial function of the ISP?
Access ISP
Name
An example of the hierarchy aspect of the Internet
Related to ISPs
Access ISPs connect to middle-tier or regional ISPs, which are connected to tier 1 or backbone ISPs.
What are ISPs?
ISPs are networks. The initial function of an ISP was to give Internet access to an individual or company, and now it is performed by an access ISP.
What are nodes?
The Internet is consist of a set of fibre-optic cables laid under the sea and across the land, which can be described as a mesh structure. The mesh of cables contains many points where the cables connect together, which we call nodes
Where are the Routers found in the Internet?
At each node
What are routers?
At each node there is a device called the router. It is conncted to several other routers and its function is to choose the best route for transmission
Name
Another name for 1st tier ISP
Backbone ISP
Name
Another name for middle tier ISP
Regional ISP
What is the type of topology the Internet is conncted in?
Mesh topology
Where else other than nodes are routers found?
Within the ISP networks
Name
PSTN full form
Public Switched Telephone Network
Name
POTS full form
Public Old Telephone Service
What is the formal name of POTS
PSTN
What is PSTN?
PSTN is a communication system that was not originally designed for computer networking but now provides significant infrastructure support for the internet
In the past, What type of signals did telephone networks carry?
It carried analog signals, however digital signals could be used if there were a modem at each end to convert digital signals to analog.
What are modems?
Modems convert digital signals to analog signals that are then sent down a telephone line. Another modem might be there to reverse the process accordingly
Why did companies paid for leased line service?
In the past
Companies would be provided with a dedicated and permenant connection link with garanteed transmission speed
What did companies use to establish WANs and MANs?
In the past
Leased line service
How did PSTN upgrade their main communication lines?
Switched it to Fibre optic
How did upgrading the main communication lines of PSTN benefit it?
It allowed improved leased line services to ISPs and allowed them to provide their own ISP services.
What are the 2 types of services provided by the mordern PSTN?
- Broadband network connection
- WiFi Hostpot technology
How are cell phones provided with an Internet connection?
Mobile phone companies act as ISPs. The phone is equipped with a software that communicates with standard cell tower, to access wireless telephone network, providing connection to the internet
