Each femtocell uses a single IPsec tunnel to protect and secure all transmissions through the internet to the femtocell gateway.
A femtocell security gateway is a specially adapted (or designed) IP router which can handle huge numbers of concurrent IPsec tunnels, encrypting and decrypting in real time. Specially designed silicon hardware is used to achieve this high throughput, which can grow to be as much as 1,000,000 concurrent sessions in a single rack.
This types of equipment is also used for other IP tasks, such as securing webpages and business VPN (Virtual Private Network) connections.
