This protocol sequence specifies RPC directly over SPX. There are no intermediate protocols between RPC and SPX. An implementation MAY<6> support this protocol sequence.

When extensions that are not specified in sections 2.1.1 through 2.1.2 are enabled over the SPX transport protocol, the network address MUST be either a Netware machine name or a network and node number. For more information, see [IPX], IPX Addressing.

The endpoint MUST be a 16-bit unsigned integer port number. The network address of the server and the endpoint are not transmitted over the network by these extensions but are used by lower-layer protocols to set up the connection.

RPC over SPX MUST use an endpoint mapper well-known endpoint of 34280.