Glossary
Acceptor
Session in the role of an acceptor is the receiving party of the FIX session. It listens to the incoming connection on the pre-defined port. The acceptor has the responsibility to perform the first level authentication and formally declares the connection request, “accepted” through the transmission of an acknowledgment Logon message.
Conditionally required fields
Fields, which are required, are based on the presence or value of other fields.
Delimiter character
The non-printing, ASCII “SOH” (\u0001, hex: 0x01, referred to this document as <SOH>), is used for field termination.
MsgSeqNum field
Integer message sequence number, the tag number is 34.
FIX
The Financial Information Exchange (FIX) Protocol is a message standard, developed to facilitate the electronic exchange of information that is related to securities transactions. It is intended for use between trading partners whose wish is to automate communications.
FIX Connection
It is comprised of three parts: logon, message exchange, and logout.
FIX Dialect
A customized, specialized or extended implementation of the base FIX protocol standards.
FIX Session
It is comprised of one or more FIX Connections, meaning that a FIX Session spans multiple logins.
Initiator
Session-Initiator establishes the telecommunications link and initiates the session via transmission of the initial Logon message.
Required Fields
Each message within the FIX protocol is comprised of required, optional and conditionally required fields (fields which are required based on the presence or value of other fields). Systems should be designed to operate when only the required and conditionally required fields are present.
Unknown Fields
Fields in a FIX message that are not expected in accordance with the FIX protocol or its dialect.
SenderCompID Field
Assigned value used to identify firm sending message, the tag number is 49.
TargetCompID Field
Assigned value used to identify receiving firm, the tag number is 56.
User-defined Fields
These fields are intended to be implemented between consenting trading partners and should be used with caution to avoid conflicts, which will arise as multiple parties begin implementation of the protocol. The tag numbers 5000 to 9999 have been reserved for them. These tags can be registered/reserved via the FIX website.
User-defined Messages
Messages those format is privately defined between the sender and receiver. A “U” as the first character in the MsgType field (i.e. U1, U2, etc) indicates such messages.
FAST
The binary encoding method for message oriented data streams. FAST is an acronym for FIX Adapted for STreaming.