Hello friends,

I am trying to think of a method for tunneling ICMP to our lovely N900 device? An ICMP tunnel establishes a covert connection between two remote computers (a client and proxy), using ICMP echo requests and reply packets. This is great for mobile providers which permit ping to your phone (assuming you have a public IP from your phone provider), but disallow all incoming ports to your phone (as if you were running a firewall with all incoming traffic denied).

The idea is to have an application that allows you to reliably tunnel TCP connections to a remote host using ICMP echo request and reply packets, commonly known as ping requests and replies. I have read that Linux programs called Loki or Ptunnel have this functionality... for a 1996 review of ICMP tunneling by Phrak Magazine see http://www.phrack.com/issues.html?issue=49&id=6

Use Case Scenario: You're on the go, and stumble across an open wireless network (not cellular, in this case, but Wi-Fi). The network gives you an IP address, but won't let you send TCP or UDP packets out to the rest of the internet, for instance to check your mail. What to do? By chance, you discover that the network will allow you to ping any computer on the rest of the internet. With ICMP tunneling, you can utilize this feature to check your mail, or do other things that require TCP.

Does anyone have any ideas if we can get this functionality on the N900, or what would be involved in recompiling Loki or Ptunnel for the N900? I work in IT, but fairly new to Linux, so any help is appreciated =)

Thanks!