PBF rules allow traffic to take an alternative path from the next hop specified in the route table, and are typically used to specify an egress interface for security or performance reasons. Let's say your company has two links between the corporate office and the branch office: a cheaper internet link and a more expensive leased line. The leased line is a high-bandwidth, low-latency link. For enhanced security, you can use PBF to send applications that aren’t encrypted traffic, such as FTP traffic, over the private leased line and all other traffic over the internet link. Or, for performance, you can choose to route business-critical applications over the leased line while sending all other traffic, such as web browsing, over the cheaper link.