Imported from previous forum
I am a novice to Fix protocol.I wanted to know abt resending of messages. Assume that the A,B are doing transactions.And A has sent a message with sequence number 50 . After this, A reseted the message sequence number and sent abt 10 messages .Again assume that it has resetted the message sequence number.
Now is it valid for B to ask A to resend messages with sequence number 50? Similarly can it ask A to resend the first few message after the first reset.
Can this be allowed for any no of levels ( resets)?.
[ original email was from Dean Kauffman - dean.kauffman@tradeweb.com ]
Raj,
I’m not sure I understand the scenario you’ve given in the context of the FIX protocol. Sequence numbers are meant to provide for an orderly flow, and resetting them as you describe is chaotic and not something you should devote any code to.
The sequence number is used in the FIX protocol to ensure that messages are processed in the correct order and without gaps. The receiving end of the channel will request resends of missing sequences and queue up higher sequences until the gaps are filled, and it follows that the receiver may request resend of any sequence without limitation.
If the sending end of the channel must reset its outgoing sequence number mid-session it will send a SequenceReset/GapFillFlag(123)=N alerting the receiving end of disaster recovery. This event effectively closes the sequence ladder of messages in the range below the NewSeqNo(36).
Hope this helps.
> I am a novice to Fix protocol.I wanted to know abt resending of messages. Assume that the A,B are doing transactions.And A has sent a message with sequence number 50 . After this, A reseted the message sequence number and sent abt 10 messages .Again assume that it has resetted the message sequence number.
> Now is it valid for B to ask A to resend messages with sequence number 50? Similarly can it ask A to resend the first few message after the first reset.
> Can this be allowed for any no of levels ( resets)?.
>