SAP filters conserve network bandwidth and are especially useful in large Novell installations where hundreds of SAP services exist. In general, the use of SAP filters is recommended for services that are not required for a particular network. Remote sites, for example, probably do not need to receive SAP advertising print services located at a central site. SPX resides atop IPX in the NetWare Protocol Suite. If the application request requires network access, the NetWare shell packages the request and sends it to lower-layer software for processing and network transmission.
Client applications are unaware of any network access required for completion of application calls.
The services provided by NCP include file access, printer access, name management, accounting, security, and file synchronization. NetWare's NetBIOS emulation software allows programs written to the industry-standard NetBIOS interface to run within NetWare system. NetWare MHS is a message-delivery system that provides electronic mail transport. NLMs are add-on modules that attach into a NetWare system. NLMs currently available from Novell and third parties include alternate protocol stacks, communication services, and database services.