Sun Microsystems Sun Fire V100 - Manual (Page 129)

Chapter 10 Troubleshooting 111
Do the serial ports support synchronous protocols?
No.
Will the server need a null-modem cable to connect to the console port?
No. Because the Sun Fire V100 server requires the use of console port, Sun has
designed the server not to need a null-modem cable. All you need to connect a Sun
Fire V100 server to a termserver is a standard Category 5 cable.