Bandwidth requirement calculation

Hi All,

In our environment we are using MS Exchange 2007, File server and SAP on CX3-20 now in process of upgrading to CX4 we would like to replicate them using RecoverPoint or MirrorView. The distance between the sites is around 30-35kms and we need Asynchronous replication type. Can you guide us on what bandwidth/link would be required between both sites?

Any help or suggestions will be highly appreciated.