The Dynamics NAV Service Tier is also known as the Microsoft Dynamics NAV Server and is a .NET-based Windows Service
application that only works with Microsoft SQL Server databases. It uses
the Windows Communication Framework as the communication protocol for
Role Tailored clients and for Web services.
It can execute multiple
client requests in parallel and serve other clients by providing Web
service access to authenticated clients.
A key difference between the two-tier architecture with the Classic
client and three-tier architecture with the RoleTailored client and
Microsoft Dynamics NAV Server is that business logic runs on the server
instead of the client in the three-tier architecture. A simple example
is the FILE.CREATE function. In previous versions of Microsoft Dynamics
NAV, files are created on the client when code is run. With the
RoleTailored architecture, the files are created on the service itself.
The Microsoft Dynamics NAV Service Tier provides an additional layer of
security between the clients and the database. It leverages the
authentication features of the Windows Communications Framework to
provide another layer of user authentication and uses impersonation to
ensure that business logic is executed in a process that has been
instantiated by the user who submitted the request. Authorization and
logging of user requests is still performed on a per-user basis. This
ensures that all Windows authentication and Microsoft Dynamics NAV roles
and permissions that have been granted to the user are correct. It also
ensures that business logic–level auditing is still performed.