http://www.rfc-editor.org/rfc/rfc1001.txt
RFC 1001: Protocol standard for a NetBIOS service on a TCP/UDP transport: Concepts and methods, , , 1987-03-01T23:00:00-00:00This RFC defines a proposed standard protocol to support NetBIOS services in a TCP/IP environment. Both local network and internet operation are supported. Various node types are defined to accommodate local and internet topologies and to allow operation with or without the use of IP broadcast. This RFC describes the NetBIOS-over-TCP protocols in a general manner, emphasizing the underlying ideas and techniques. Detailed specifications are found in a companion RFC, "Protocol Standard For a NetBIOS Service on a TCP/UDP Transport: Detailed Specifications".