Encrypted WANs via the Internet

["Neil Chick" <chickna @ ncp . gpt . co . uk>]

Hi,

Does anyone have an experience of using encrypted links via the
Internet to join two remote sites together ?
	+ How is it done?
	+ Hardware can be bought to make it happen?
	+ How do the firewalls distinguish between the two? 
          ( I know bit a vague question just pointer would be
            helpful as I'm currently in the dark ;-) )
	+ Any idea of costs?
	+ Security implications of course;)

Any ideas welcomed....

Thanks,

Neil Chick
GPT 
UK.				Wot no sig!
chickna @
 ncp .
 gpt .
 co .
 uk .