HansCli is a lightweight version of the Hans client, written in C instead of C++, intended for use in embedded systems (eg. routers running OpenWrt).

Hans makes it possible to tunnel IPv4 through ICMP echo packets, so you could call it a ping tunnel. This can be useful when you find yourself in the situation that your Internet access is firewalled, but pings are allowed.

Hans homepage: http://code.gerade.org/hans/