Colt已经使用IPSec网络协议在IP层上进行了一段时间的加密, 但是IPSec有局限性. It is quite costly at high bandwidths and doesn't scale very well in terms of performance. 它还会增加延迟.
We can now provide end to end encryption at line rate - 100 Meg, 1G and 10G - it doesn't impact the performance and the throughput of the service.