There hasn’t been a time where the applications running on the Internet have been changing so rapidly. Applications are moving to public and private clouds, fast — putting growing pressure on the Internet performance, more specifically the WAN segment of the Internet, that services the end users. This applies both for consumer Internet services as well as enterprise WAN services. Historically, the solution has been a load balancer. How is that requirement evolving?
This accelerated change in requirements need to be matched by the next generation of Internet load balancers, which act as the maestro between the Internet and the local LAN. The legacy load balancing approaches where all traffic is treated mostly the same way, i.e. not taking advantage of the intelligence that can be extracted from the WAN links, is not on par with today’s application demands. Historically, load balancing firewalls would not have the flexibility to react to any changes in the network conditions once they blindly commit a flow to one of the WAN ISP links.
Let’s say a chatty application flow was assigned to one of your WAN lines, say WAN1. If your WAN1 experiences a performance anomaly, and believe me any service will, no matter what the SLAs are, the flow that was assigned to that link will suffer. In reality, any WAN link is an unpredictable animal that has floating specs (depending on the traffic on the link, time of the day, core network congestion or hundreds of other potential reasons), so the WAN load balancer should be able to detect, understand and accordingly react to those performance fluctuations in the Internet.
These types of shortcomings of legacy load balancing routers are primarily a result of the coarse granularity that a load balancer uses, which is at the transport session level, such as TCP session, UDP session, SIP session, etc. However, the new breed of link load balancers, more accurately named Broadband Bonding routers, are capable of reducing the granularity to an IP packet (or even below). This enables tremendous flexibility to react quickly to any changes in the network. The 25+ years of theoretical work of Network Calculus provides the foundation of this approach. Once the granularity and adaptation are within reach, the load balancer should virtualize the WAN (WAN virtualization) which creates an intelligent software layer that manages the Internet traffic across all WAN links. Think of this as a traffic cop that can direct the packets to different WAN links dynamically according to the overall view of the roads and traffic.
The legacy load balancers need to evolve to a new generation of load balancers to be able to serve the ever-changing needs of the new applications and the cloud-based paradigm. Being able to detect, classify, and react in real-time is no longer a luxury for high-end technologists, but a requirement of any multi-WAN appliance (e.g. dual WAN firewalls) to provide the best end-user experience.
Cahit Akin, CEO, Mushroom Networks, Inc.
Mushroom Networks is the provider of SD-WAN (Software Defined WAN) and NFV solutions capable of Broadband Bonding that enables self-healing WAN networks that route around network problems such as latency, jitter and packet loss.