HP Network Direr Software Products manual Configurable Retries

684CHAPTER 17: USING 3COM NETWORK DIRECTOR ON A MULTI-SITE NETWORK

while traversing the network, or if the device the request is sent to is not responding for some reason, then a response to the request will never be received by 3Com Network Director.

In order to determine when this situation has occurred, 3Com Network Director uses the standard timeout technique: if a response is not received to a request within a certain period of time (known as the timeout period), 3Com Network Director concludes that there will not be a response to that particular request.

If the route to a remote site passes over one or more WAN links that have a very high latency then some, or even all, requests to that remote site may time out. This would prevent 3Com Network Director from monitoring and managing that site properly. By increasing the timeout period you can increase the time that 3Com Network Director will wait for a response to each request, preventing incorrect timeouts from occurring and so allowing 3Com Network Director to monitor and manage that site.

Configurable Retries

If a request sent by 3Com Network Director times out then this may be due to either the request or the response being dropped while traversing the network. As a result, 3Com Network Director cannot immediately conclude that a device is not responding if it fails to respond to a request.

To cope with this situation 3Com Network Director uses the standard technique of sending retries: if a timeout occurs for a request then 3Com Network Director will try sending the request and waiting for a response a second time. Depending upon the protocol, it may retry the request multiple times before concluding that the device is not responding.

If the route to a remote site passes over one or more WAN links that are oversubscribed then some, or even all, requests to or responses from that remote site may be dropped by the routers at either end of the oversubscribed links. By increasing the number of retries you can increase the number of attempts 3Com Network Director will make with each request before concluding that the device it is destined to is not responding. This will increase the likelihood that requests sent to devices at the remote site will succeed.