The conversation ID is used for parallel processing. This is an option flag as defined in Message schema (XSD).

Option flag can be found from

<Drive>:\Program Files\Microsoft Dynamics AX\50\Application\Share\Include

<xsd: element name="ConversationId" type="ConversationIdType" minOccurs="0"/>

Messages having different conversation ID’s will be processed in parallel. Messages having the same Conversation ID are processed sequentially in the order they are received.  For example if you submitted the following messages in the specified order

 Message ID                                              Conversation ID

1                                                                     5

2                                                                     5

3                                                                     6

4                                                                     7

5                                                                     8

6                                                                     *

7                                                                     *

8                                                                     *

So Messages 1,3,4,5,6 all have unique conversation IDs and would be processed in parallel (at the same time). Messages 1,2 have the same ID, as do messages 6,7,8 (* is the default conversation ID that will be inserted automatically on files that come in through a non-parallel channel). The messages with the same ID’s have to wait until previous messages with that ID are processed.  So once message 1 is processed, message 2 will be processed (1 and 2 are in the same parallel conversation), and likewise when message 6 is done, then 7 and then 8 after that. 

Advantage:

·         Enable the processing of messages in parallel to improve performance.

For more on parallel processing/Conversation ID refer: Parallel Processing and Conversation ID