Autonomous Systems (AS) in Network Management: An Overview

What is an Autonomous System (AS)?

An Autonomous System (AS) is a collection of connected Internet Protocol (IP) networks, routers and other network equipment. The main feature of an AS is that it's administered and operated by a single organisation or entity. Each AS is distinctively identified through a unique number called an Autonomous System Number (ASN). This unique identifier is provided by the Internet Assigned Numbers Authority (IANA).

Functions and Responsibilities of an AS

1. Routing Traffic Internally: The primary responsibility of an AS is to route traffic within its network. This ensures efficient data transmission among the connected IP networks and routers.
2. Exchanging Traffic Externally: An AS doesn't operate in isolation. It exchanges traffic with other autonomous systems, ensuring a global network connection.
3. Using Routing Protocols: ASes employ various routing protocols, most notably the Border Gateway Protocol (BGP). These protocols facilitate the exchange of routing information and help in deciding the most efficient path for traffic between different networks.

Who Uses ASes?

• Internet Service Providers (ISPs): ISPs rely on ASes to manage their networks and facilitate traffic exchange with other networks.
• Large Corporations: Big businesses utilise ASes to manage their vast internal networks.
• Government Agencies: These entities use ASes to ensure secure and efficient communication across their departments and with the public.

Significance of ASes in Internet Operation

ASes aren't just a technical concept. They are pivotal in ensuring the smooth operation of the internet as a whole. By forming the backbone of the global routing system, they enable traffic to move seamlessly across the internet, connecting different corners of the world.