3.2.3.5.5 IN_R1/A1 and IN_R2/A1 RTS PDUs
The IN_R1/A1 RTS PDU and the IN_R2/A1 RTS PDU have the same format and are processed identically by the inbound proxy. This section defines processing for IN_R1/A1 only, but the same processing rules apply to IN_R2/A1.
An inbound proxy implementation MUST NOT accept this RTS PDU in any state other than Open_Start. If received in any other state, this PDU is a protocol error and the inbound proxy MUST treat it as a protocol error as specified in section 3.2.3.5.10.
If this RTS PDU is received in Open_Start state, the inbound proxy implementation MUST retrieve the virtual connection cookie from the IN_R1/A1 RTS PDU and search for a matching entry in the virtual connection cookie table. If found, it MUST execute the sequence of steps in section 3.2.3.5.5.1. If not found, it MUST execute the sequence of steps in section 3.2.3.5.5.2.