If your modem speed is limited by the 38400 speed of your Sun's 'zs' serial port
and if you also have a PC running Windows 95 or Windows NT, try 'WinGate'
This let's your Sun share a modem attached to your PC's high speed serial port,
so your Sun uses Ethernet to talk to your modem via WinGate on Win95/NT.
The WinGate software is free for use by a single client machine (e.g. your Sun)
and the latest version 1.3.08 became available 31st March at WWW address:
Or for related information refer there via http://www.veryComputer.com/