Which technique uses file sharing or an instant messenger client such as Meebo running over...

Tunneling is a method of transporting data across a network using protocols that are not supported by that network. Tunneling works by encapsulating packets: wrapping packets inside of other packets. Tunneling within commonly used services is a technique that uses file sharing or an instant messenger client such as Meebo running over HTTP to bypass firewalls or other network restrictions. The data packets are encapsulated within HTTP packets and sent as normal web traffic. This way, the data packets can reach their destination without being blocked or detected by the network. References: What is tunneling? | Tunneling in networking | Cloudflare, What Is Network Tunneling & How Is It Used? | Traefik Labs, networking - What is HTTP tunneling? - Stack Overflow