Branch office tunnel Contivity 221 with NAT routers in between 1

[HungryHouse]

Anyone have experience with the Contivity 221 with NAT?
Nortel does branch office tunnels slightly differently with these 221s apparently.
Here is scenario

221#1(bcm50e)-----Nat Rtr1---Internet---Nat rtr2---221#2

We are having a heck of a time trying to get even Phase I IKE Ipsec up and running all. Negotiation is failing.
The units are reachable.
In our test scenario, Nat rt1 is a Cisco 830 and Nat rtr2 is a Cisco PIX with port500 and ESP open. We've even tried opening all ports and no changes in negotiation.
Local and remote network match.
Parameters of tunnel are esp w/3DES MD5. IKE, tunnel mode.

The Nat routers are Nating the public addy on each side...and I have tried Nat traversal.

I know the VPN tunnel can be established without the NAT rtrs because I had it up when in lab#1 using standard routing and advertising the real addy. Now, in lab#2, am using Internet IPs but no success.

Any help is appreciated...

 

[HungryHouse]

Hey all- we figured it out. The content and the Ip address within the tunnel had to be different and then all worked.
Peace. -DK