A centralized deployment model presupposes the existence of an efficient WAN environment. If a suitable WAN infrastructure is not in place, you must account for the cost in equipment, installation, and possible downtime while you deploy the required hardware. Because client-server transactions generate more network traffic than server-host transactions, this deployment model may yield less-responsive client-server connections when compared with a branch model.
With no SNA Server computers in the branch offices, you also lose the ability to use the Windows NT Server computers upon which SNA Server runs as multipurpose servers. If other server applications need to be implemented at the branch locations, you will need to install additional computers and hardware.