Internet Security, Connectivity, and Remote Access Products from Sonic
   including the Bandit, a LAN-to-dialup hub.
   http://www.sonicsys.com/

Klos Technologies, Inc.
   Klos Technologies specializes in protocol analyzer tools and network protocol stack (PPP, TCP/IP, IPX) development.
   http://www.klos.com

NTS
   Develops TCP/IP infrastructure products to simplify administration and improve the reliability and security of intranets. Product lines include Shadow IP Services to simplify IP address management, and TunnelBuilder software for secure Intranet access.
   http://www.NTS.com

The Mac Orchard - Connectivity Applications
   TCPSerial
   http://www.macorchard.com/connect.html