AR (Aggregation Router)

An Aggregation Router (AR) is a critical networking device that plays an important role in modern network architecture. It is responsible for aggregating traffic from multiple lower-level networks and forwarding it to a higher-level network, such as an Internet Service Provider (ISP). The AR is commonly used in large enterprise networks, service provider networks, and even in data center networks.

In this article, we will discuss in detail what an AR is, its function, how it works, its importance, and the different types of ARs available in the market.

What is an Aggregation Router (AR)?

An Aggregation Router (AR) is a networking device that collects and routes traffic from multiple lower-level networks to a higher-level network, such as an Internet Service Provider (ISP). It serves as the boundary between the customer’s network and the service provider network. ARs are generally deployed at the edge of a network and provide the connection between the customer network and the service provider network.

The primary function of an AR is to aggregate traffic from multiple access routers, which are connected to the customer’s network, and forward it to the service provider network. It also provides several services such as Quality of Service (QoS), security, policy-based routing, and traffic shaping.

How does an Aggregation Router work?

The AR works by receiving traffic from multiple access routers, which are connected to the customer network. The AR then aggregates this traffic and forwards it to the service provider network. The AR uses different protocols such as Border Gateway Protocol (BGP), Open Shortest Path First (OSPF), and Intermediate System-to-Intermediate System (IS-IS) to communicate with other routers in the network and exchange routing information.

The AR uses a routing table to determine the best path for the traffic to reach its destination. The routing table contains information about the network topology, such as the IP addresses of the routers and the paths between them. The AR uses this information to calculate the best path for the traffic to reach its destination.

The AR also provides several services such as Quality of Service (QoS), security, policy-based routing, and traffic shaping. QoS ensures that the traffic is prioritized based on its importance, and it receives the necessary resources to ensure its timely delivery. Security ensures that the network is protected from unauthorized access and that the data is secure. Policy-based routing allows the network administrator to define policies that determine how the traffic is routed based on certain criteria such as the source or destination IP address, the type of traffic, or the time of day. Traffic shaping allows the network administrator to control the amount of traffic that is sent across the network.

Importance of an Aggregation Router

An Aggregation Router is an important component of modern network architecture. It provides the connection between the customer network and the service provider network, ensuring that traffic flows seamlessly between them. The AR provides several services such as Quality of Service (QoS), security, policy-based routing, and traffic shaping, which are critical for the efficient operation of the network.

The AR also provides scalability and flexibility to the network. It allows the network administrator to add more access routers to the network without affecting the overall performance. The AR also allows the network administrator to change the routing policies and QoS settings, ensuring that the network can adapt to changing traffic patterns and requirements.

Types of Aggregation Routers

There are several types of Aggregation Routers available in the market, each with its own set of features and capabilities. The three most common types of Aggregation Routers are:

1. Modular Aggregation Router

A Modular Aggregation Router is a chassis-based router that allows the network administrator to add or remove line cards as needed. This type of router is highly scalable and can support a large number of access routers. It also provides high availability and redundancy, as it can be configured with redundant power supplies, fans, and control cards. This type of router is typically used in large enterprise networks and service provider networks.

2. Fixed Aggregation Router

A Fixed Aggregation Router is a router that comes with a fixed number of ports and cannot be expanded. This type of router is less scalable than a Modular Aggregation Router, but it is less expensive and easier to manage. It is typically used in small and medium-sized enterprise networks.

3. Virtual Aggregation Router

A Virtual Aggregation Router (VAR) is a software-based router that runs on a virtual machine or a container. It provides the same functionality as a hardware-based router but is more flexible and easier to manage. VARs can be deployed quickly, and the resources can be allocated dynamically based on the traffic requirements. They are typically used in cloud-based environments, data center networks, and Software-Defined Wide Area Networks (SD-WANs).

Conclusion

In conclusion, an Aggregation Router (AR) is a critical component of modern network architecture. It serves as the boundary between the customer network and the service provider network, providing the connection between them. The AR aggregates traffic from multiple access routers and forwards it to the service provider network. It also provides several services such as Quality of Service (QoS), security, policy-based routing, and traffic shaping.

There are several types of Aggregation Routers available in the market, each with its own set of features and capabilities. The most common types are Modular Aggregation Routers, Fixed Aggregation Routers, and Virtual Aggregation Routers. The choice of the type of AR depends on the network requirements, the size of the network, and the budget.