Mysql Database replication behind a router

[Rafiek]

I have a question.
I need to replicate a mysql database with a mysql database on a external webhost.
It has to be a master-master replication. The problem my local database is behind a adsl-router. I have no rights to adjust settings in the router. The company that installed it has thse rights.
Is it possible to replicate a database from behind a router without tweaking the router??
if not we have to ask the company to do port forwarding.