Two upgrades at the same time from the same host?

Hi,

i have two systems in the same windows host. I would like to upgrade both the systems parallel at the same time.

I understand that the SL Controller will be started for both the systems. What i dont understand is the port 4239 to get into upgrade GUI. Both uses the same port. How is this possible? Can i start two upgrades at the same time?

Thanks in advance.

Regards,

Mohan.