Sami,
To measure the RTT use the command, "ips measure-rtt interface gigabitethernet ", this will send a ping issued from the FCIP engine on the linecard to the destination IP address, which should be the other end of the FCIP tunnel. If your RTT changes slightly due to network issues, don't worry, the MDS continuously updates the RTT in real-time. The value is initially used for when the fcip tunnel first comes up and then the automated measurements take over.
To determining min/max bandwidth I would recommend working with your WAN team to determine what your expected bandwidth should be as they may be limiting you or guarateeing you with QOS. For example use the following questions with them:
What is the maximum amount of bandwith that is being allocated to FCIP traffic by the LAN/WAN?
For the min value, asking "What is the minimum amount of bandwidth that is guarenteed by the LAN/WAN?"
You can use various methods to test the speed of the FCIP tunnels such as the MDS CLI "san-ext-tuner" or use your arrays with valid data (the luns could be full of zeroes which would give you false stats due to them being compressed). You could either fill the luns with valid data or disable compression. Then watch the stats on the GigE ports (post compression stats) or the FCIP tunnels (pre-compression stats).
-Seth
