I have a site that recently implemented an IP telephone system. It went from a flat IP network to a structured network with VLANs and QOS. After the implementation, users started complaining that their applications began to have poor performance. These applications varied from e-mail client, mapped drive file access to telnet client response. Network statistics (pings & SNMP utilization stats) from switches and routers do not show any items of particular concern or high response times. Anything else that you can think of that I can look at without having to spend lots of $$$ to analyze the problem? Note that the infrastructure is all Cisco and there are no complaints at all concerning voice or call quality.
Thanks in advance.