Effective at the close of business on Friday, June 25, 2004 at the Remote Data Center (RDC) and Friday, July 9, 2004 for the Wacker Drive location, the Chicago Mercantile Exchange Inc. (CME) is releasing a new version of the Market Data Network (MDN) which will provide better performance, stability, and new functionality for Distributors. On the server side, the new version more than triples message throughput, leading to faster message delivery to Distributors.

All of these changes are transparent to Distributors. Distributors can continue to log in with their existing usernames and passwords and receive CME market data. However, Distributors can take advantage of the new functionality to automatically receive retransmissions of the current session’s market data, without having to contact the CME.

In order to request retransmissions for market data, Distributors will need to initiate a new connection to an MDN Gateway. For reference, a normal logon looks like the following:

<LOGON><USERNAME=username><PASSWORD=password></LOGON>

In order to initiate a connection to receive retransmitted market data only, two new fields need to be added to the logon string.

<LOGON><USERNAME=username><PASSWORD=password>

<START SEQUENCE=start_sequence><STOP SEQUENCE=end_sequence></LOGON>

(Note: The actual logon string contains no carriage return or line-feed characters).

As the logon string shows, both a start sequence number (start_sequence) and a stop sequence number (stop_sequence) are required. This new connection will only receive the requested market data within the specified range and then close the connection automatically.

The following logon shows how to receive messages from sequence numbers 100 to 200.

<LOGON><USERNAME=username><PASSWORD=password>

<START SEQUENCE=100><STOP SEQUENCE=200></LOGON>

There are a few points to take into consideration when requesting retransmissions using the new logon string:

• Distributors will be given new usernames and passwords for requesting  retransmissions of market data. Distributors should not utilize any of their existing connections as this will prevent their use for receiving real-time market data.
  
• Users should be sure to use the logon associated with the channel over which the retransmission is desired.  For example, a username of “ZZ_CHN1PRD” will receive retransmitted data from channel one (Floor).
  
• Retransmitted market data requested using this logon will be sent at real-time speeds, not at a slow rate as is done for retransmissions requested today. Care must be taken that there is sufficient bandwidth available to receive the requested data.   If not, we recommend that your break the retransmission request into smaller sequence number ranges.
  
• If some of the requested messages have not yet been sent as real-time data, the MDN Gateway will ensure that only messages that have already been sent are retransmitted.
  
• As with retransmissions performed today, the current trading session’s market data will become unavailable when the trading day ends. If a retransmission is started and does not complete before the end of the trading day, the connection will be closed.
  
• A connection established for purposes of retransmission will never send any real-time data.
  
• If either the start or stop sequence numbers contain non-numeric characters, then the Distributor is disconnected without receiving any data.  (Distributors should take care when entering numeric zero that they don’t enter the alpha character “O”.)
  
• If the Distributor has not supplied a complete logon string within 60 seconds, the connection is closed.
  
• If the Distributor sends a starting sequence number that cannot be found (maybe the MDN Gateway was down, retransmissions have been turned off by the CME, or if the requested sequence number has not been sent), no data is sent and the connection is closed.
  
• Any characters in the logon string outside of any ‘<’ ‘>’ pairs are ignored. Once the MDN Gateway has read all of the elements of the Distributor logon string, it stops reading input from the Distributor.
  
• Distributors are only allowed a single connection per username. If a Distributor attempts to connect twice with the same username, then the original connection is closed. Therefore, if Distributors see a need to request more than one retransmission for a specific channel at a time, they should request additional logons.
  
• Retransmissions can still be performed using the existing method of manually requesting a retransmission from the CME computer room. The retransmitted market data will be sent over an existing connection with real-time data.

If you wish to test the new functionality in our new certification environment, please contact us.

If you have any questions regarding this memo, please contact Marilee Radecki at 312.930.8193 or email mradecki@cme.com, or Lisa Amato at 312.338.2654, email lamato@cme.com.  Thank you.

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