how to enable VPN between these router and allow through PIX

[sivaprakasam81]

Hi All,

how to enable VPN between these router and allow through PIX?

Site I :  T1

Router Cisco 1721

        Firewall CISCO PIX 506e

Site II :  T1

Cisco 1721

        Firewall PIX506e

Site III:  Bonded T1

Router :CISCO 12651

Firewall: Cisco PIX 515r

Thank you,

Siva

[Todd Pula]

http://www.cisco.com/en/US/tech/tk583/tk372/technologies_configuration_example09186a008009486e.shtml

http://www.cisco.com/en/US/products/ps6120/products_configuration_example09186a008045a2d2.shtml