Balancing and Failover

The Elfiq Link Balancer product line brings a new level of bandwidth management and uptime to any organization looking to improve their overall competitiveness and reduce costs.  At the core of every Elfiq Link Balancer, the three following functions are included:

• Outbound link balancing: Organizations can use multiple (aggregate) ISPs for outbound traffic to the Internet so the load will be distributed.  This process can be customized to meet specific needs and requirements or to match the best possible use existing bandwith with the use of seven algorithms.
• Inbound link balancing: Services available over the Internet can be easily performed with Elfiq's Intelligent DNS technology
• Link failover: The Elfiq Link Balancer will continually monitor the health of each ISP and distribute bandwidth as long as it is operating in a normal fashion.  When a carrier link fails to respond normally, the Elfiq Link Balancer will remove it from the list of ISPs for bandwidth management and keep on testing it.  When it becomes available, it will be used normally with the other carrier links. 

  When a carrier link fails, the sessions are re-started onto an alternate link, and for granular control over the failover process, the Intelligent Condition Verificator will bring a new level of control.  To complement this ability, the Intelligent Condition Verificator can handle complex scenarios and guarantee bandwidth for key services while performing failover tasks.

To perform inbound and outbound balancing activities, each Elfiq Link Balancer can use the following seven advanced algorithms to process data. These algorithms can also be used in customized fashions through Traffic Segmentation to meet organizational requirements.  The algoritms can be used for balancing as well as failover processes.

The nine available algorithms are:

• Round Robin: with this algorithm, each link receives traffic an equal number of times, regardless of bandwidth usage.
• Weight First Algorithm: the WFA algorithm gives preference to one link and when the link is saturated to a certain level, the Link Balancer uses another link for traffic distribution
• Reverse Weight First Algorithm: this algorithm provides the same benefits as WFA but in reversed order, which can be very useful in certain deployments
• Least Traffic First Algorithm: the LTFA algorithm will distribute traffic on a set of links based on the level of saturation, where the least saturated will receive new traffic flows.
• Equalized Traffic First Algorithm: the ETFA will distribute traffic equally across a set of links, making sure they are all used with the same amount of traffic continually.
• Weighted and Equalized Traffic First Algorithm: the WETFA algorithm will distribute traffic equally on a set of links and when a defined saturation point is met, one or more additional links will handle future traffic requests
• Ordered Preferred First Algorithm: the OPFA algorithm will distribute sessions based on user-defined preferences in regards to the order in which the links will be used
• Force Ordered Preferred First Algorithm: the FOPFA algorithm will force a session based on customer-defined parameters onto a specific carrier link when the desired link is available
• Round Robin No-GMAC: the RR-GMAC algorithm is used when redirecting incoming sessions off-site. A GMAC is an link’s (or gateway’s) MAC address, the Elfiq Link Balancers operate for balancing activities under a Layer-2 implementation.

The Elfiq Link Balancer's traffic routes can be adjusted to your granular requirements through Traffic Segmentation.  Elfiq Networks' Link Balancers can direct traffic from and to services on links specified by the organization’s policies to provide optimal traffic management and cost management.  This is possible for both inbound and outbound balancing.

An example of this feature in production would be to assign symmetrical links to applications which benefit them such as VPNs and keep asymmetrical traffic on asymmetrical links such as ADSL and cable modems for lower priority traffic such as web surfing. In this example, expensive links are not employed for web surfing since this activity does not fully use the capabilities of the link.

Traffic segmentation is also a first step in a Quality of Service (QoS) implementation.