Hitachi

JP1 Version 12 JP1/Network Node Manager i Setup Guide


5.1.2 Network latency and timeouts

Normal network latency influences the amount of time the NNMi management server must wait to get answers to ICMP and SNMP queries. Different areas of a network customarily have different turnaround times. For example, the local network where the NNMi management server resides could provide nearly instantaneous response, while responses from a device in a remote geographical region accessed through a dial-up wide area link would typically take much longer.

In addition, heavily-loaded devices might be too busy to respond to ICMP or SNMP queries immediately. When deciding which timeout and retry settings to configure, consider these latency concerns.

You can configure specific timeout and retry settings for both network regions and specific devices. The settings you choose determine how long NNMi waits for an answer and how many times NNMi requests data before abandoning the request when no answer is received.

For each request retry, NNMi adds the configured timeout value to the previous timeout value. Thus, the pause gets longer after each retry. For example, when NNMi is configured to use a timeout of five seconds and three retries, NNMi waits five seconds for a response to the first request. If there is no response, NNMi waits for 10 seconds for a response to the first request retry, 15 seconds for a response to the second request retry, and 20 seconds for a response to the third request retry before giving up until the next polling cycle.