3 Protocol Details
MSSearch Query Protocol message requests require only minimal sequencing. All messages MUST be preceded by an initial CPMConnectIn message (for example, at least one CPMConnectIn for each named pipe connection). Beyond the initial connection, there is no other sequencing required by the protocol. However, it is advised that the higher layer adhere to a meaningful message sequence; and for messages that are received out of this sequence or with invalid data, the protocol server will respond with an error. Note that some messages are also dependent on the higher layer, providing valid data that was received in messages earlier in the sequence.
A typical message sequence for a simple search query from a protocol client to a remote computer is illustrated in the following diagram.
The messages represented in the preceding diagram represent a subset of all of the MSSearch Query Protocol messages used for querying a remote query server search catalog.