Incorrect response to invalid sequence reset acknowledgment

Hi,

We work on a number of FIX implementation where users connect to us using the QuickFIX FIX engine. Ours us a Cameron Engine. We offer 2 sessions - an Order Session and a MKD Session for each user.

We have been observing issues lately with Logon sessions with 141=Y at initial startup. There are 2 different issues we have observed that we need to attend urgently. We have worked numerous possibilities including modifying Configuration settings, but to no avail. Also, it is not viable for us to request all QuickFIX users to modify the source.

1) Client sends Logon with 141=Y with MsgSeqNum=1. Cameron replies with Logon Acnowledgment but without 141=Y and SeqNum=1. QuickFIX is unable to handle the Logon Acknowledgment with missing 141 Tag. QuickFIX assumes that the initial Logon was not acknowledged and sends a second Logon with SeqNum 2. Cameron sees a duplicate Logon request (whilst already connected) and rejects the Logon message. At this point, although both systems are connected, the Engine goes into a strange state and certain procedures such as MKD requests begin failing.

2) Client sends Logon with 141=Y. Cameron sends Logon Acknowledgment without 141=Y and SeqNum=1. QuickFIX assumes that no Logon Acknowledgement was received. QuickFIX then sends the following message, for eg., a TestRequest or Heartbeat with SeqNum=1. Cameron sees MesgSeqNum lower than the expected SeqNum of 2 and terminates the session.

Thanks. Nataraj.