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Only the Edge platform combines this form of
enhanced session control with advanced policy-routing. When
deployed in a multilink environment, this technology can ensure
that critical applications maintain the session persistence
required in order to prevent disconnects which can happen when
ISP links are load balanced.
(Click to Enlarge)
Session Persistence is critical for
maintaining connectivity when load balancing Internet traffic
across multiple links. The problem is that most link load balancers
do not incorporate the ability to properly monitor, manage,
and control session persistence across various types of network
applications and those which do, often require that ALL traffic
be forced out a specific WAN link.
This translates either to non-optimized performance, or potential
disconnects for mission critical traffic, either of which is
a significant issue for maintaining productive end-user connectivity.
By design the EdgeXOS platform has built-in technology which
ensures reliable bandwidth management across multiple WAN links,
and thus our products ensure both optimized performance when
utilizing multiple links AND complete session persistence for
mission critical applications like VoIP, Citrix, CRM and ERP.
Intelligent Vector Mapping
Vector Maps are used to ensure session persistence
so that traffic that comes in via a particular WAN link goes
back out the same link. This is critical for most web-based
e-commerce applications, including SSL based applications.
By creating Vector Maps, an IT administrator can ensure proper
application balancing and failover for inbound services. This
is a key component to providing a total network load balancing
solution. Generally Vector Maps are required whenever PAT or
One-to-One NAT mappings are used for inbound services.
VirtualNAT
Similar to application proxy solutions VirtualNAT enables
inbound services to be proxied to internal servers and network
devices. There are some limitations to VirtualNAT (it does not
support some applications) and always shows inbound connections
coming from the Edge appliance. However it's simple configuration
makes it the favorable method for load balancing inbound traffic
under most circumstances.
How Does It Work
Our ESP technology tracks sessions in real-time and will
automatically ensure that each session maintains its "stickiness"
to a specific WAN link once the session has been initiated.
The administrator also has the ability to re-direct application
traffic on a per application and/or per destination basis.
Further, the network administrator can also create policy
routes whereby the ESP module will split sessions between links
but only when those sessions can be split without causing disconnect
problems. This capability is unique in the EdgeXOS platform
and is one of the ways in which we ensure network optimization
in multi-link deployments.
By monitoring each outbound session
the EdgeXOS platform is able to optimize outbound connections
by fully utilizing each WAN link to its fullest which maximizes
ROI for the end-user.
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Enhanced
Session Policies (ESP)