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Voice+Nat+IPsec+ALG + Overlapping networks ( 10.X.X.X) between sites


I would appreciate some opinions about my lab test for a future purpose of integration ICT ( Inter Cluster Trunk ) between Brazil Mercatinle Exchange - BMF/Bovespa and Chicago Mercantile Exchange - CME

Lab test:

1) Two routers with VPN Site to Site- IPSec ( Router 7200 => real network = Site A - Brazil /  Router 1800 => simulating site B - EUA )

2) Behind site B I have a IP Phone 7911 . It is registered with CUCM at site A

3)  Behind router 7200 => CUCM + other IP phone for teste between this phone and 7911 at site A

4) Site A and Site B : overlapping networks = 10.X.X.X

5) Both Routers : 7200 and 1800 configured with NAT + ALG + VPN/IPsec

6) Behind router 7200 there is a firewall but with ports open to permit signaling sccp, udp traffic I do not have problem

I have more details fot this design that was implemented , but I won´t write a long email so far. For those who will readinf for help it´s better

I got this results.:

- Phone 7911 is registering with CUCM

- Signaling exchanges it is OK ( I checked this in log files - firewall behind 7200 )

- NO RTP traffic between 2 IP phones.

When phone 7911 -  in site B  - call  phone on site B, phone on site B rings. BUT there is no voice traffic.......

What can be done to solve this?

Thanks and best wishes.

Dimitri Félix