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NYSE Liffe Gateway

Understanding the Price Feed Optiq

Price Feed Behavior

TT Gateways receive market data via the Euronext Optiq Market Data Gateway (MDG), which provides high-speed, real-time market data for Euronext markets.  All market data provided from the exchange are FAST optimized.


Due to the large amount of data, Euronext requires users to use lines with sufficient bandwidth. Refer to the exchange documentation to determine the appropriate amount of bandwidth for your trading environment.

Delivery Mechanism

This system provides market data using four mechanisms:

Market Data Feeds


Delivery Mechanism


Standing Data

EFS download

Supplies tick table, point value and additional market data prior to the product open.

Market Data


Real-time data broadcast via dual multicast streams (A and B)



Used to request missing data packets via a direct TCP/IP connection.


TCP/IP for request and response

Multicast for the data transfer

Supplies a snapshot of order book data following an intraday restart.

EFS Standing Data

The exchange provides initial product definitions as Standing Data .xml files which the gateway downloads via the exchange's Euronext Files Services (EFS) site.

Market Data Multicast

The MDG feed delivers real-time data broadcast via dual multicast streams (labeled Stream A and Stream B). TT Gateways receive the same data along both streams. In most cases, if a data packet is missing on one stream, the gateway should be able to recover the missing packet from the other stream.

Retransmission Server

If the gateway cannot retrieve missing data from the market data streams, the TT Gateway will request data from the exchange by establishing a TCP/IP connection with the exchange's Retransmission Server.

Refresh/Replay Server

Following an intraday restart, the TT Gateway may request a full snapshot of the current order book data by establishing a TCP/IP connection with the exchange's Refresh Server. The gateway will also rely on the Refresh Server if it cannot connect to the Retransmission Server. Once the exchange forwards a response, the TT Gateway will join the refresh multicast to receive the missing data.

Since this type of request includes all current market data, recovering data from the Refresh Server takes longer than receiving data via the Retransmission Server.

Price Server Data Flow

The following describes the data flow of the Price Feed connection from the Price Server on the TT LIFFE Connect Gateway to the exchange.

  • When available, the TT Gateway downloads the standing datafiles from the exchange's EFS server.
  • The Price Server starts and reads configuration values from the aconfig.xml file.
  • The Price Server reads the standing data files for all Multicast Groups.
  • Using the data from the corresponding standing data files, the Price Server begins adding product information to the Product Table for all subscribed products.
  • For each multicast group, the Price Server validates the current sequence number from the exchange.
  • If a gap exists between the last sequence number recorded by the Price Server and the sequence number provided by the exchange, the Price Server requests the missing data from the exchange's Retransmission Server.
  • Following a trader login, the Price Server begins forwarding market data to the client application
  • Note

    TT Gateways use the exchange Grouped channels for all market data.

    Also, the gateway calculates market data such as the high/low price using data from the price feed. The gateway does not use the exchange's Value Added Price channels.