Polling groups are especially important in multisite environments that are managed from a single IP Availability Manager or IP Performance Manager. You must consider connection speeds and latency that might differ because of network location.
Refer to your network diagram to locate WAN links that the IP Manager polls must cross to reach devices. Based on the latency of the links, you might have to adjust the polling cycles. These types of modifications are difficult to perform accurately before the actual deployment because the traffic load across the links that the IP Manager polls might not be readily available. Expect to revisit the polling settings during the validation and tuning phase.
If latency becomes an issue that cannot be overcome with realistic polling groups, you must reconsider your design. If the network includes many lower speed links, it might be necessary to relocate physically one or more Domain Managers or even increase the number of Domain Managers to reduce the latency.
As an aside, by setting the MaximumLatency parameter in the Connectivity Polling setting to a non-zero number, you can configure the ICMP latency monitoring feature. If the round-trip time exceeds a user-defined latency value, but does not exceed a user-defined timeout value, the IP Manager generates an IP SlowResponseTime event.