1.3.1 RDP-UDP to RDP-UDP2 Transition
The Remote Desktop UDP Transport Extension v2 protocol has two distinct phases of operation. The initial phase, UDP Connection Initialization, occurs when a UDP connection is initialized between the terminal client (2) and the terminal server. Data pertaining to the connection is exchanged and the UDP connection is setup as described in [MS-RDPEUDP]. After this phase is completed successfully and an RDPUDP_PROTOCOL_VERSION is negotiated, this value is used to determine which version of the UDP transport extension will be used for the Data Transfer phase. If the negotiated RDPUDP_PROTOCOL_VERSION is RDPUDP_PROTOCOL_VERSION_2 or earlier, the protocol enters the RDP-UDP Data Transfer phase, where Coded Packets are exchanged according to the protocol described in the [MS-RDPEUDP] document. If the negotiated RDPUDP_PROTOCOL_VERSION value is greater than RDPUDP_PROTOCOL_VERSION_2, the protocol enters the v2 Data Transfer phase, where Coded Packets are exchanged according to the protocol described in the current document.
Figure 2: Relationship between RDP-UDP to RDP-UDP2