The Internet is commonly viewed as one unified global network. The reality is much different; it consists of a huge number of independent networks united in a common set of rules.
In order to comprehend how the information transfers globally, you need to learn about What is Autonomous System (AS) Design. These systems can be considered the basic blocks for maintaining the connections around the world.
An Autonomous System is a big set of IP addresses and routers that are managed by one distinctive organization, either a large university, a mega-corporation, or even a governmental institution.
Imagine the global internet as a worldwide postal system. Computers may be compared to houses; however, AS is more like a whole area of a postal delivery in a certain city.
Without knowing the way to these areas, information cannot get from one house to another across the globe. Each system has its own policy of routing and a special identification number called an ASN (Autonomous System Number).
Such huge networks make up the backbone of the entire internet structure and can be classified according to their connectivity and interaction with each other:
Such networks charge money for transferring information from one end to another. They serve as huge information carriers that connect different continents with each other.
Two different networks decide to connect themselves and transfer traffic among each other without any monetary cost since both of them stand to benefit from it.
Such small networks have connections with just a single upstream network and take care of all their internal traffic, but depend upon the larger network to connect with the rest of the internet.
For these networks to communicate effectively, constant exchanges must take place regarding what destination is reachable by each of the two networks. This intricate process of cross-network communication requires extensive BGP routing (Border Gateway Protocol).
While internal routers ensure that data transfer within a network takes place efficiently, BGP becomes necessary for the transfer of data across different networks. ISP networks utilize BGP routing to inform other neighboring networks of their connectivity options.
The smooth operation of the internet as a whole is a result of the seamless cooperation among independent systems. With the grouping of routers into manageable networks, the internet ensures that there is no chaos in data transfer.
The understanding of the relationship between the basic systems, ISPs, and border routing protocols gives insight into the marvels of how data travels across the globe.
