[asterisk-users] Connecting branch offices through IPsec tunnel --latency effects?

[Rich Adamson]

Dan Austin wrote:
> Stephen wrote:
>> If I connect two offices through an IPsec tunnel, what is the impact
> on
>> latency, and does it noticeably affect calls?
> That would depend a lot on the equipment that services the IPSEC tunnel
> endpoints.
> 
>> Has anyone out there tried this? What were the effects?
> I've run small to mid size offices (20 to 60 people) over IPSEC
> tunnels during periods of internal network failures with good results.
> That includes offices on the opposite side of the world with one-way
> latency normally around 100ms, but often up to 160ms.
> 
> Using commercial IPSEC endpoints, or OpenSWAN on a decent system only
> adds a couple of ms, if that.

I might add that I did a little research for a non-voip project relative 
to what cisco 28xx routers could sustain in terms of ipsec-vpn 
throughput. The cisco doc's report 55 mbs sustained throughput.

On the flip side, the older cisco routers can't sustain 500 kbs without 
adding a hardware encryption board to the router.

So, you are probably very right with the "depends a lot on the 
equipment". ;)