Black Box LRU4240 - Manual (Page 26)

14 SALES: 0870 90 10 750 Dual Trunk E1 Router User’s Guide
Dual Trunk E1 Router
A
PPLICATIONS
Dual independent links application
Load balancing
When multiple paths exist to the same destination, sending all IP packets on a single route is
probably not the most efficient use of the available bandwidth. Load balancing is the practice of
distributing traffic among multiple paths to the same destination to achieve higher throughput and
avoid delays.
The Dual E1 Trunk Router IP routing engine maintains a cost metric parameter with each route
learnt dynamically or programmed statically. If more than one route of equal cost is found for a
particular destination, the routing engine will distribute the packets equally among the available
routes using a round-robin algorithm.
If multiple routes are found with unequal costs then the route with lesser cost metric is chosen.
Redundancy
With multiple paths to the same destination, the routing engine also performs redundancy at both
the physical layer and the network layer. By monitoring the status of the physical link interface and
the PPP negotiation, the unit knows when a link is physically down or a PPP connection is down.
When either events occurs, the routing engine will balance traffic to the active link.