A new approach leverages cloud scalability to offer an easier, more cost-effective alternative to branch office security. The existing methods of evolving branch security force IT into a tough trade-off: the cost and complexity of managing appliance sprawl or the complexities of a two-tier network security architecture. Instead, organizations continue with their branch routers and firewalls, but backhaul all traffic to a larger firewall with public Internet access, typically hosted in a regional co-location hub. The approach is similar to the regional hub approach, but with a difference: the service provider isn’t responsible for building and running the hubs.
Source: https://thehackernews.com/2017/12/firewall-bursting-new-approach.html