The TDS 4.2 protocol does not prescribe a specific underlying transport protocol to use on the Internet or on other networks. This protocol only presumes a reliable transport that guarantees in-sequence delivery of data.
The chosen transport can be either stream-oriented or message-oriented. If a message-oriented transport is used, then any TDS 4.2 packet sent from a TDS 4.2 client to a TDS 4.2 server MUST be contained within a single transport data unit. Any additional mapping of TDS 4.2 data onto the transport data units of the protocol in question is outside the scope of this specification.
The TDS 4.2 protocol has implementations over the following transports: