FIX 4.1 : StandardHeader

Structure | Used In

Description

Each administrative or application message, is preceded by a standard header. The header identifies the message type, length, destination, sequence number, origination point and time

Two fields helps with resending messages. The PossDupFlag <43> is set to Y when resending a message as the result of a session level event (i.e. the retransmission of a message reusing a sequence number). The PossResend <97> is set to Y when reissuing a message with a new sequence number (e.g. resending an order). The receiving application should process these messages as follows:

  • PossDupFlag <43> — if a message with this sequence number has been previously received, ignore message, if not, process normally.
  • PossResend <97> — forward message to application and determine if previously received (i.e. verify order id and parameters).

The following table provides examples regarding the use of SenderCompID <49>, TargetCompID <56>, DeliverToCompID <128>, and OnBehalfOfCompID <115> when using a single point-to-point FIX session between two firms. Assumption (A=sellside, B=buyside):

SenderCompID OnBehalfOfCompID TargetCompID DeliverToCompID
A to B directly A B
B to A directly B A

The following table provides examples regarding the use of SenderCompID <49>, TargetCompID <56>, DeliverToCompID <128>, and OnBehalfOfCompID <115> when using a single FIX session to represent multiple firms. Assumption (A=sellside, B and C=buyside, Q=third party):

SenderCompID OnBehalfOfCompID TargetCompID DeliverToCompID
Send from A to B via Q
1) A sends to Q A Q B
2) Q sends to B Q A B
B responds to A via Q
1) B sends to Q B Q A
2) Q sends to A Q B A
Send from A to B *AND* C via Q
1) A sends to Q A Q B
2) Q sends to B Q A B
3) A sends to Q A Q C
4) Q sends to C Q A C
B *AND* C send to A via Q
1) B sends to Q B Q A
2) Q sends to A Q B A
3) C sends to Q C Q A
4) Q sends to A Q C A

Structure

Tag Field Name Req'd Comments
8 BeginString Y

FIX.4.1 (Always unencrypted, must be first field in message)

9 BodyLength Y

(Always unencrypted, must be second field in message)

35 MsgType Y

(Always unencrypted, must be third field in message)

49 SenderCompID Y

(Always unencrypted)

56 TargetCompID Y

(Always unencrypted)

115 OnBehalfOfCompID N

Trading partner company ID used when sending messages via a third party (Can be embedded within encrypted data section.)

128 DeliverToCompID N

Trading partner company ID used when sending messages via a third party (Can be embedded within encrypted data section.)

90 SecureDataLen N

Required to identify length of encrypted section of message. (Always unencrypted)

91 SecureData N

Required when message body is encrypted. Always immediately follows SecureDataLen <90> field.

34 MsgSeqNum Y

(Can be embedded within encrypted data section.)

50 SenderSubID N

(Can be embedded within encrypted data section.)

142 SenderLocationID N

Trading partner LocationID (i.e. geographic location and/or desk) (Can be embedded within encrypted data section.)

57 TargetSubID N

'ADMIN' reserved for administrative messages not intended for a specific user. (Can be embedded within encrypted data section.)

143 TargetLocationID N

Trading partner LocationID (i.e. geographic location and/or desk) (Can be embedded within encrypted data section.)

116 OnBehalfOfSubID N

Trading partner SubID used when delivering messages via a third party. (Can be embedded within encrypted data section.)

144 OnBehalfOfLocationID N

Trading partner LocationID (i.e. geographic location and/or desk) used when delivering messages via a third party. (Can be embedded within encrypted data section.)

129 DeliverToSubID N

Trading partner SubID used when delivering messages via a third party. (Can be embedded within encrypted data section.)

145 DeliverToLocationID N

Trading partner LocationID (i.e. geographic location and/or desk) used when delivering messages via a third party. (Can be embedded within encrypted data section.)

43 PossDupFlag N

Always required for retransmitted messages, whether prompted by the sending system or as the result of a resend request. (Can be embedded within encrypted data section.)

97 PossResend N

Required when message may be duplicate of another message sent under a different sequence number. (Can be embedded within encrypted data section.)

52 SendingTime Y

(Can be embedded within encrypted data section.)

122 OrigSendingTime N

Required for message resends. If data is not available set to same value as SendingTime <52> (Can be embedded within encrypted data section.)

Used In

Onix Solutions