2.1.1 TCP Transport
This section specifies the protocol to use TCP as specified in [RFC793] to transmit method invocation and return information.
If instructed by a higher-level protocol in an implementation-specific way, an implementation of this protocol MUST require the implementation of the [MS-NNS] protocol on the server to authenticate the TCP client using SPNEGO.
The higher-level protocol MUST provide, in an implementation-specific way, the required credentials for the authentication. Implementations of this protocol MUST NOT process the credentials or authentication information before transmission. Such processing typically happens entirely inside implementations of lower protocol layers. An extension of this protocol MAY use the credentials from the lower protocol layers for authorization or impersonation.