How to forward H323 calls?

Hi all,

We are in VoIP termination business. It seems that someone in betweeon one of our clients and ourselves filters traffic (not my ISP, already checked), so their calls are not reaching us. Since we do not have similar problems with other customers, I would like to do following:

-Rent server somewhere
-Install Asterisk
-Route all calls using that server to my gateways

By this, I hope we are going to use different route so problems will be avoided. Our clients use H323 and G723/G729 codecs.

-Is something like this possible with Asterisk ?
-Is it advisable ? Someone tried it ?
-Since we just want to route calls, not terminate them, would we need to purchase codecs ?