Synchronize two sql servers 2005

I need to sync two sql server 2005 instances between intranet and extranet (through a firewall). Synchronization will be initiated from the intranet. What solutions do I have at my disposal?

intranet db: table t1 -> extranet db: table t1

intranet db: table t2 <- extranet db: table t2

i.e. the contents of intranet t1 must be pushed to extranet t1 and contents of intranet t2 must be pulled from extranet t2.

We're going to sync every hour.