Policy-Based Routing (PBR)

What Is Policy-Based Routing?

Policy-based routing (PBR) is a methodology used to direct and manage data packet flow based on predefined policies or filters. It empowers network administrators to apply policies selectively, considering specific parameters like source and destination IP addresses, ports, traffic types, protocols, access lists, packet sizes, and more, thus enabling the routing of packets along custom-defined paths.

The primary objective of PBR is to enhance network agility. By tailoring routing behavior to suit application attributes, PBR furnishes administrators with flexible and fine-grained traffic handling capabilities. Consequently, it facilitates optimal bandwidth utilization for critical business applications, ensuring that network resources are allocated efficiently to meet organizational needs.

Problems Policy-Based Routing Addresses

Traditional routing systems typically route traffic based solely on the destination of the packets. However, the evolving landscape of technology, marked by the proliferation of cloud computing, mobility, and web-based applications, necessitates a more nuanced approach. In response, Policy-Based Routing (PBR) emerges as a crucial tool. Unlike traditional methods, PBR allows networks to discern and handle each application type individually, enabling efficient prioritization, segregation, and routing of traffic without compromising performance or availability.

Moreover, the convergence of voice, data, video, and diverse applications on the same network introduces significant complexity. This complexity not only heightens vulnerability to threats but also hinders networks' ability to effectively respond to such threats. Today's core business applications are prime targets for cyber attackers employing sophisticated, multi-pronged attacks. PBR empowers network administrators to classify traffic based on applications and designate them for further analysis. This approach enhances visibility, enforcement, control, and protection, thereby bolstering network security against a myriad of potential threats.

What Can You Do with Policy-Based Routing?

You can use PBR to:

• Implement Quality of Service (QoS) measures to prioritize applications by leveraging high-bandwidth, low-latency links for critical applications in scenarios where multiple links are accessible. For instance, prioritize corporate data transmission over rapid connections and assign slower links for Internet browsing traffic.

• Utilize load-sharing strategies to create a backup link for critical traffic in the event of a failure on the primary link carrying essential application traffic. This ensures seamless continuity and redundancy for mission-critical services.

• Segregate traffic for thorough inspection or analysis by enabling network administrators to classify application traffic that necessitates deep inspection and auditing. Optionally, administrators can route this traffic to a distinct device dedicated to analysis and inspection purposes.

• Manage subscriber traffic within service provider networks by implementing traffic management policies and rules tailored to subscribers' profiles. For instance, Policy-Based Routing (PBR) can prioritize and route specific types of application traffic along designated routing paths by Service Level Agreements (SLAs), or by assigning higher priority to certain user requests based on subscription tiers such as gold, silver, or bronze.

• Offer a secured Service Level Agreement (SLA) for the delivery of specific traffic types, such as video traffic, by ensuring that authorized traffic obtains the necessary priority, routing, and bandwidth allocation to uphold the highest level of user experience quality.

• Utilize Policy-Based Routing (PBR) to direct particular applications for WAN optimization. By classifying traffic based on applications, the network administrator can route the traffic to the WAN optimizer, enhancing the speed of access to crucial applications and data.