I am looking to get some ideas/recommendations on a network monitoring software solution for our network. Currently we have CiscoWorks in our environment but I was looking to get more into a solution for monitoring deeper into how our network is performing. I have some experience with SolarWinds, which has become quite pricey. I thought I would see what other professionals have experience with. I have started to do some reading on Nagios and Whats Up Gold. We have a pretty big WAN environment with the better part of it running on a fiber backbone with CWDM. We are getting ready to deploy 1600 VoIP phones and have some multicast video apps going on. We would like to be able to see some traffic stats and reports as well as monitoring. Any suggestions and recommendations would be appreciative.