After a bit of googling I found that: Microsoft® SAC does not implement hardware control flow. Therefore, when console redirection is enabled with EMS SAC, you will see corrupted data. As SAC does not implement hardware flow control, you are unable to effectively use SOL Proxy to activate console redirection to EMS SAC. This can result in corrupted screen output caused by missed characters. Slower baud rates correct this situation and still provide good user experience.
I installed SOL proxy on the PC which is in the same LAN with the server in question (R320). I can connect to the BMC console redirection. If I for example do "Reboot and activate console redirection" I have access to the console (eg I could enter BIOS and change settings). However once the R320 boots into Windows 2008 R2 there is SAC to load on the console. It prints SAC version and goes to prompt "SAC>" and thats it. there is no interaction with the telnet any more. whatever i press on the remote keyboard nothing works. the prompt just there and I can terminate session but killing the telnet client. I used Putty. I also tried stock Windows telnet and went to 'Activate console redirection' connected to the R320 and got small string of garbage chars and thats it (I think it was SAC again as Windows was booted on the R320 at that moment). Whats wrong with it?
Using BMC console redirection through SOL proxy hangs SAC