Operational Notes

FIX services are available 24/7 except during software deployments, which occur Friday evenings approximately every two weeks for UAT environments and monthly for Production environments.

FIX session reset schedules

TT resets all FIX sessions on Saturdays at 22:00 UTC and sends the reset message sequence numbers to FIX clients the first time they log in to a FIX session after that time. This default reset always occurs, in addition to any session resets configured for a FIX session in Setup. Similarly, for custom reset schedules, message sequence numbers only after a FIX client first logs in after the scheduled reset time.

Note If a FIX client remains connected to a FIX session when either the default or scheduled time occurs, sequence numbers will not reset until the FIX client logs out and logs back in to the FIX session.

On-demand sequence number resets

By default, message sequence numbers for FIX sessions are reset when TT resets all FIX sessions. Message sequence numbers can also be reset, when desired, by setting Tag 34 (MsgSeqNum) = 1 and Tag 141 (ResetSeqNumFlag) = Y when sending a Logon (A) message.

ClOrdID uniqueness

TT FIX will ensure ClOrdID (tag 11) uniqueness for:

  • All orders entered since the last session reset (Saturday @ 22:00 UTC by default or per custom schedule in Setup)
  • All GTC / GTDate orders entered in previous sessions that were still working at the start of the current sesssion.

For more information, refer to the ClOrdID tag description in the New Order Single (D) message.

CME TT Inbound Drop Copy support

In order to add support CME Drop Copy 4.0 in the TT Inbound Drop Copy service, tags 5024 and 5979 have been added to the TT XML schema Service as shown:

<field number='5024' name='StartSequenceNumber' type='SEQNUM' />
<field number='5979' name='RequestTime' type='INT' />

These tags will not appear in any messages used by TT standard outbound drop copy service or any other customer-facing FIX interfaces.

No customer action is required regarding these tags.