1.3.9 Connect-Time and Continuous Network Characteristics Detection
Connect-Time Auto-Detection occurs once during the RDP Connection Sequence (section 1.3.1.1), and is accomplished by sending request and response messages over the main RDP connection during the Optional Connect-Time Auto-Detection phase.
The following messages are encapsulated in the server-to-client Auto-Detect Request PDU (section 2.2.14.3) and flow over the main RDP connection, implementing Connect-Time Auto-Detection:
RTT Message Request (section 2.2.14.1.1)
Bandwidth Measure Start (section 2.2.14.1.2)
Bandwidth Measure Payload (section 2.2.14.1.3)
Bandwidth Measure Stop (section 2.2.14.1.4)
Network Characteristics Result (section 2.2.14.1.5)
The following messages are encapsulated in the client-to-server Auto-Detect Response PDU (section 2.2.14.2) and flow over the main RDP connection as part of Connect-Time Auto-Detection:
RTT Measure Response (section 2.2.14.2.1)
Bandwidth Measure Results (section 2.2.14.2.2)
Network Characteristics Sync (section 2.2.14.2.3)
Continuous Auto-Detection occurs on a constant basis after the RDP Connection Sequence has completed, and is implemented by sending request and response messages over the main RDP connection and any created sideband channels ([MS-RDPEMT] section 1.3.2).
The following messages are encapsulated in the server-to-client Auto-Detect Request PDU and flow over the main RDP connection, implementing Continuous Auto-Detection:
RTT Message Request (section 2.2.14.1.1)
Bandwidth Measure Start (section 2.2.14.1.2)
Bandwidth Measure Stop (section 2.2.14.1.4)
The following messages are encapsulated in the client-to-server Auto-Detect Response PDU and flow over the main RDP connection as part of Continuous Auto-Detection:
RTT Measure Response (section 2.2.14.2.1)
Bandwidth Measure Results (section 2.2.14.2.2)
The following messages are encapsulated in the RDP_TUNNEL_SUBHEADER ([MS-RDPEMT] section 2.2.1.1.1) structure and are used to implement Continuous Auto-Detection over the sideband channels that are in active use:
Bandwidth Measure Start (section 2.2.14.1.2)
Bandwidth Measure Stop (section 2.2.14.1.4)
Network Characteristics Result (section 2.2.14.1.5)
Bandwidth Measure Results (section 2.2.14.2.2)