You can take tcpdump from client side and also on IVE (Troubleshooting -> Tools -> tcpdump)
Is it particular location which is finding it slow? It could be related to network then and not IVE.
1. Try logging in as same user from some other location to see if you still find it a problem
2. If you still find it slow from other location too, check if users from certain role are finding issue.
3. Check if particular type of access is slow e.g. NC, WSAM/ JSAM or web rewrite as well.
It involves checking debuglog from client machine to check the delay.
