In today’s IT best practices, load balancing routers are one of the cornerstones of WAN (Wide Area Network) architecture. The reliance on a high performance and highly available Internet connectivity is a direct result of the services shifting to centralized, private, or public cloud-based WAN architectures.
Load balancing routers sit right at the LAN/WAN boundary of the office and therefore take on many functions at that critical gateway location. So, as a network administrator, what capabilities should you require for your load balancing router?
Broadband Bonding at packet granularity: With today’s deep-packet inspection and high packet processing capabilities of routers, the load balancing router should implement the aggregation at packet-level granularity. This is not only proven to be significantly more efficient in terms of bandwidth utilization, but also opens the door for many other sophisticated and useful features. Once the load balancing router has the capability to act on each packet (and sometimes at even smaller granularity) there is a wide-range of networking techniques that can be leveraged over multiple WAN connections that can result in better application performance.
In multi-office deployment scenarios, the ability to split up individual sessions into packets become even more important, as a rudimentary session-level load balancing router will lack the ability to utilize the bandwidth beyond a single WAN link. This is primarily because there is only a single session that exists at the branch office – the VPN tunnel that connects the branch to the headquarters. Your load balancing router should be able to split up the single VPN session into smaller packets and spread them over the available WAN resources to take full advantage of the multi-WAN environment.
Another important advantage of having a packet level load-balancing router is that the loss of any of the links (or packet losses on that link) will not impact the continuity of the session. In other words, during a file transfer, VoIP call or Citrix session, if one of the WAN links that is carrying part of the traffic fails, this negative WAN link behavior can be shielded from the application layer, therefore providing a much improved user experience even during network failures.
Traffic grooming capabilities: The best-of-breed load balancing routers will have capabilities beyond broadband bonding such as identifying traffic, grooming the identified traffic to behave in certain ways, and also shaping the WAN link in order to allocate bandwidth according to the applications running through the WAN. A practical example is to have the capability of traffic shaping any of the WAN links, including the bonded tunnel, so that certain types of real-time traffic (such as VoIP / SIP traffic) can be assigned a dedicated and prioritized virtual pipe and therefore get protection against other traffic stepping over it and creating QoS (Quality of Service) issues.
Load balancing routers with bandwidth shaping, quality of service reservation capabilities and certain application specific treatment of traffic for better performance, are all high-value-added capabilities of today’s gateway devices.
Fundamental additional modules: Load balancing routers can and should be equipped with certain optional features and modules that facilitate specific deployment scenarios. Examples include firewall capabilities, content filtering features, network monitoring and analysis, and others. These are primarily features that can be obtained via another network appliance in the network, however, the additional value of combining these features into the load balancing router is usually an option that the IT manager appreciates.
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.