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1.3.1 Version Negotiation sequence

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This sequence occurs on the device enumeration channel. The client and the server negotiate the protocol version by exchanging the Select Version Request (section 2.2.2.1) and Select Version Response messages (section 2.2.2.2). The client sends the highest protocol version it supports in the Select Version Request and receives the protocol version selected by the server in the Select Version Response. These two messages MUST be the first messages exchanged. All subsequent protocol messages MUST use the negotiated protocol version. The client MUST support all the protocol versions less than the highest one it supports.<1>

Figure 1: Version Negotiation sequence