1.4 Relationship to Other Protocols
The Tabular Data Stream (TDS) protocol depends upon a network transport connection being established prior to a TDS conversation occurring (the choice of transport protocol is not important to TDS).
TDS depends on Transport Layer Security (TLS)/Secure Socket Layer (SSL) for network channel encryption. In the TDS 7.x version family, TLS/SSL is optional and the negotiation of the encryption setting between the client and server and the initial TLS/SSL handshake are handled in the TDS layer.
Introduced in the TDS 8.0 version, TLS is mandatory and is established in the lower layer before TDS begins functioning.
If the Multiple Active Result Sets (MARS) feature [MSDN-MARS] is enabled, the Session Multiplex Protocol (SMP) [MC-SMP] is required.
This relationship is illustrated in the following figure.
Figure 2: Protocol relationship