The use of network（71）,systems that effectively isolate an organization's internal network structure from an（72）network, such as the INTERNET is becoming increasingly popular. These firewall systems typically act as application-layer（73）between networks, usually offering controlled TELNET, FTP, and SMTP access. With the emergence of more sophisticated（74）layer protocols designed to facilitate global information discovery , there exists a need to provide a general （75）for these protocols to transparently and securely traverse a firewall.
