To keep two instances of AMPS synchronized, AMPS includes full replication functionality. For high-availability or to populate a disaster recovery instance, 60East recommends replication. See the AMPS User's Guide for more details.
If, instead, you need to transform or enrich messages as they're delivered, or if you don't need the level of reliability that AMPS replication provides, you can create an AMPS Bridge.
The article "Light-weight AMPS Bridge", on our blog, has full instructions and a downloadable sample program.