Port Closure - Frequently Asked Questions

What is the purpose of the CME Globex Port Closure Policy?

To protect CME Group markets and systems from potentially detrimental behavior.

What are some examples of detrimental behavior that can cause the CME Global Command Center ("GCC") to close an iLink session port?

  • Repeated incorrect login attempts
  • Repeated invalid order submissions (bad price/qty and etc.), modifications, or cancels
  • Repeated resend requests

What steps can market participants take to avoid the closing of an iLink session port?

It is recommended that trading entities properly monitor administrative and business level reject messages to ensure that order entry systems have proper order reject handling capabilities. It should be noted however that CME Group expects electronic activity to be monitored at all times.

When will the GCC take action on an iLink session that is exhibiting detrimental behavior?

If the GCC detects behavior, either iLink or Network based, that may be potentially detrimental to CME Group Globex markets or systems, and this behavior is not corrected in a timely manner, the GCC will take action by either closing the port for the applicable iLink session, or blocking problematic IP ranges. Please note, all such actions are subject to regulatory review.

Is there a fee associated with an iLink session port closure?

Firms will incur a $1,000 port closure fee, for each event, per session, per day (up to $10,000 per registered entity) for behavior which results in the closure of an iLink session ports, or IP range blockage by CME Group.


Who is assessed the charge for iLink session port closures?

The CME Registered Entity that is the administrative owner of the GFID/iLink session causing the detrimental behavior. This charge will appear as “Port Closure Fee” on the Registered Entity's monthly statements under the Description column.


Is a waiver policy in place which allows impacted participants to request reconsideration of the CME Globex port closure fee?

CME Group will consider waiver requests if non-repeat customers can demonstrate real-time monitoring and prompt corrective measures have been implemented.


Will an iLink session's port be closed if there are working orders?

Yes, an iLink session’s port will be closed regardless of whether there are working orders or not.

What is the impact of a port closure to an iLink session's working orders?

All day orders will be cancelled if tag 49, SenderCompID, has been enabled with Cancel on Disconnect.

Once an iLink session’s ports have been closed, how can I cancel working orders if tag 49, SenderCompID, has not been Cancel on Disconnect enabled?

After the execution of a port closure or IP range blockage, trading entities that do not employ the COD functionality will have the ability to cancel working orders by using Kill Switch, FirmSoft, or by having a registered contact call GCC.

What will be the time limit given to firms to address detrimental behavior before the CME closes an iLink session’s port?

The GCC may take immediate action in addressing potentially detrimental behavior.

When can an iLink session's port be reopened?

iLink session ports will be reopened only if GCC determines the detrimental behavior has been corrected. The GCC will require a written explanation ensuring the customer has complete understanding of the system failure. In addition to the explanation, the GCC will require detailed information as to what mitigating and programmatic steps the customer will put in place to ensure the offending activity does not occur again.

Who has the authority to request an iLink session port reopening?


Only registered Clearing firm or Risk administrators have the authority to request the reopening of an iLink session port.


Who should be contacted to reopen an iLink session port?


Clearing firm primary or secondary administrators should contact the GCC in U.S. at +1 800 438 8616, in Europe at +44 20 7623 4747 or in Asia at +65 6532 5010 and choose option 3.


How long does it take the GCC to reopen an iLink session port?

The process usually takes the GCC 5 to 15 minutes.

More on Globex

Client Systems Wiki
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Messaging Efficiency Program
Learn about the CME Globex Messaging Efficiency Program.


CME Group Login
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Support from the CME Global Command Center (GCC).


Contact Us

Global Account Management (GAM)
U.S.: +1 312 634 8700
Europe: +44 20 3379 3754
Asia: +65 6593 5505

CME Global Command Center
U.S.: +1 800 438 8616
Europe: +44 20 7623 4747
Asia: +65 6532 5010
Email: gcc@cmegroup.com
Website: www.cmegroup.com/gcc

Certification Support for Electronic Trading (CSET)
U.S.: +1 312 930 2322
Europe: +44 20 3379 3803
Asia: +65 6593 5593
Email: cset@cmegroup.com