4.1.1 Version Negotiation

Protocol version negotiation is implicit in accepting and returning a ConnectResponse containing a ResponseId Ok. Although the currently supported versions of SSTP are 1.5 and 1.6, the following illustrates a possible future scenario in which an updated version of SSTP has been specified as version 3.6.

Figure 12: Connect accepted: implicit version negotiation

Following this initial connection (1), both devices exchange message conformant to SSTP version 3.5 only. If either device subsequently detects an incoming byte stream which does not comply with the version 3.5 specification, the receiving device treats it as a protocol error.