A few months ago, when we would plug in our 500 system, the MCP card would stop responding to telnet, OSM, etc. You could ping it but when trying to access it via OSM, nothing. We have 4 other 100's hitting it, and 1 of the 400's receives its phone service from it. When we take it offline and make it into its own network, it works just fine, but the remote offices can't 4 DID dial. It happens randomly and we have to turn off and on the system for it to recover. Could be up for 5 days then keep going down everyone 15 minutes.

The first thing which must be done it is update to last available software……
The second thing it is your network structure and as a supposition maybe a lot of broadcasts or other services messages - you need to monitor the network...