Quotes Direct diverges from CME FIX/FAST in regard of Incremental data arbitration.
In order to provide a faster service, CQG utilizes one Incremental UDP feed and one Replay TCP Service. The client systems shall check the FIX messages to find a missing message, which may occur due to UDP connection nature. If such occurs, the client system shall request the required messages from the Replay server using standard FIX message.
The client system should process the feed as follows:
1. Listen to the Incremental feed
2. Process messages by incremental sequence number (tag 34-MsgSeqNum).
3. If a sequence number (tag 34-MsgSeqNum) gap is detected – this would indicate a packet was lost on the Incremental Feed. Client systems would need to initiate the Recovery process (refer to Recovery for additional information).
Processing of messages as follows:
Messages are received at client system from Incremental Feed as following:
1. Receive message on Incremental Feed – tag 34-MsgSeqNum=26.
2. Process the message tag 34-MsgSeqNum=26.
3. Receive message on Incremental Feed – tag 34-MsgSeqNum=27.
4. Process the message tag 34-MsgSeqNum=27.
5. Receive message on Incremental Feed – tag 34-MsgSeqNum=28.
6. Process the message tag 34-MsgSeqNum=28.
7. Receive message on Incremental Feed – tag 34-MsgSeqNum=30.
8. Process the message tag 34-MsgSeqNum=30.
9. Gap detected!
10. Begin the recovery process as applicable.