Install guide

1-6 Release Note
Software Version 2.7.5
C613-10454-00 REV A
The following figure shows how the round trip response times are used to
determine which port the load balancer will use for its data traffic.
This figure illustrates the timing delays for a series of healthcheck messages
transmitted from 2 ports on a router, where each port is sending healthchecks
to a common host via its own respective network. The distance travelled by the
healthchecks is indicated by the vertical arrow shown on the left-hand side of
the chart, whilst their delay is measured on the horizontal time scale. An
average response time, based on the last 4 healthchecks, is shown by the grey
bars, which are measured by the time scale shown on the right-hand side of the
chart.
The following table shows the last 4 response times recorded for each port
together with their average values.
Because messages transmitted from port 2 have an average response that is
twice as fast as those from port 1, the load balancer will select port 2 twice as
often as port 1 for the data it transmits during the next healthcheck interval.
Note that because the WAN load balancer healthcheck’s messages are based on
ICMP packets, the response times recorded may not reflect the latency for other
traffic types. Also, it is important that the sites chosen as healthcheck hosts are
appropriate. For example, public servers can get overloaded with requests.
Selecting these servers as healthcheck hosts could produce unrealistic results.
Port Last 4 response times Average
1 50,50,150,150 100
2 55,50,50,45 50
1 second 1 second
WANLB_WFR_Graph
Network Response Times for Port 1
200 ms
100 ms
100 ms
Network Response Times for Port 2
Distance to Host Distance to Host
Healthcheck Interval
(set to1second)
50 ms
200 ms
50 ms 50 ms
1 second 1 second 1 second
1 second 1 second 1 second 1 second 1 second
150 ms 150 ms
55 ms 50 ms 50 ms 45 ms
Network Response Time (Running Average) = 50 ms
Network Response Time (Running Average) = 100 ms
Healthcheck
Healthcheck
Average
Response
Times
200 ms
50 ms