[Asterisk-Dev] IBM/SGI implementations

[Florian Weimer]

* James Sharp:

> Some quick research shows that it should be easy to do.
>
> open /dev/crypto & lock it
> Recieve packet.
> Stuff packet into crypto data structure along with key
> pull trigger on ioctl using /dev/crypto file descriptor
> get decrypted packet out of structure
> close /dev/crypto & unlock it
> continue processing decrypted packet.

And what about the context switching overhead?

The problem is that VoIP applications use rather small packets.  I
would be surprised if crypto accelerators result in significant
improvements.  My notebook performs about 500,000 AES operations on
256 byte blocks per second, and you'll have trouble building a machine
that can process this many packets per second in user space, even it
completely lacks any crypto support.