Application gateways and the extra hop problem Application gateways examples Web-based application gateway FTP used Application gateways examples Chapter 5: Tunneling and Application Gateway We have learned: Interface to Multiprotocol environment Mixing network technologies lat for TCP/IP a Clients and servers in constrained environments Application gate Application gateway examples oe comp using SuPar Ppp TCp/INtemet5 哈工大计算机学院 李全龙 Network Application Development Tunneling and Application Gateway 25 Application gateways and the extra hop problem IP gateway To rest of internet IP gateway App gateway machine To rest of internet 哈工大计算机学院 李全龙 Network Application Development Tunneling and Application Gateway 26 Application gateways examples FTP server Web server CGI prgrm Disk Browser HTTP used FTP used User Cmptr. Gateway Cmptr FTP Cmptr „ Web-based application gateway 哈工大计算机学院 李全龙 Network Application Development Tunneling and Application Gateway 27 Application gateways examples Dialup phone sys Dialup phone sys OS with support for TCP/IP SLIRP gateway Home computer using SLIP or PPP Host on the TCP/IP Internet Interface to dialup modem Standard socket interface to TCP/IP 哈工大计算机学院 李全龙 Network Application Development Tunneling and Application Gateway 28 Chapter 5: Tunneling and Application Gateway We have learned: „ Multiprotocol environment „ Mixing network technologies „ Encapsulation and tunneling „ Clients and servers in constrained environments „ Application gateways „ Application gateway examples