# Incorrect gap filling

**URL:** <https://forum.fixtrading.org/t/incorrect-gap-filling/12678>\
**Category:** General Q&A\
**Tags:** imported, xid\_169924, fix-technology\
**Created:** [January 28, 2013, 1:38pm UTC](https://forum.fixtrading.org/t/incorrect-gap-filling/12678 "2013-01-28T13:38:31Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![zadiriushk\_x](https://avatars.discourse-cdn.com/v4/letter/z/779978/32.png) [@zadiriushk\_x](https://forum.fixtrading.org/u/zadiriushk_x)\
**Post date:** [January 28, 2013, 1:38pm UTC](https://forum.fixtrading.org/t/incorrect-gap-filling/12678/1 "2013-01-28T13:38:31Z")

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Imported from previous forum

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**Author:** ![zadiriushk\_x](https://avatars.discourse-cdn.com/v4/letter/z/779978/32.png) [@zadiriushk\_x](https://forum.fixtrading.org/u/zadiriushk_x)\
**Post date:** [January 28, 2013, 1:38pm UTC](https://forum.fixtrading.org/t/incorrect-gap-filling/12678/2 "2013-01-28T13:38:31Z")

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According to FIX 4.4 specification it’s implied that if message gap occurs and one of the counterparties recognizes it and sends ResendRequest message, other counterparty must resend demanded non-administrative messages with PossDupFlag = Y and also it must transmit administrative messages as SequenceResets (GapFill)

So what is the correct behavior when other counterparty sends demanded non-administrative messages without PossDupFlag=Y ?  
Should we process it as usually do? Should we reject it or something?

Example:

A: 35=0, 34=100  
B: 35=0, 34=200  
A: 35=D, 34=110   
B: 35=2, 34=201, 7=101, 16=109  
A: 35=D, 34=101, 43 isn’t presented   
B: ???

I’m also interested how administrative messages should be processed in this case.

Example:

A: 35=0, 34=100  
B: 35=0, 34=200  
A: 35=D, 34=110   
B: 35=2, 34=201, 7=101, 16=109  
A: 35=1, 34=101   
B: ??? (should we send Heartbeat?)

Thanks for any help.

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**Author:** ![adityakapur](https://yyz2.discourse-cdn.com/flex010/user_avatar/forum.fixtrading.org/adityakapur/32/179_2.png) [@adityakapur](https://forum.fixtrading.org/u/adityakapur)\
**Post date:** [January 29, 2013, 4:49pm UTC](https://forum.fixtrading.org/t/incorrect-gap-filling/12678/3 "2013-01-29T16:49:59Z")

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Actually in the first example – the third message will be rejected since the new order was sent with a lower sequence number (110) than the previous one (200) and the session will be logged out.

Having said that – moving onto the fifth message in the sequence – if the counterparty does not attempt to satisfy your resend request and continues to send messages with a lower sequence number (101) without setting the PossDupFlag (43=Y) then the session should be logged out since it is akin to sending messages with a lower sequence number.

Same is the case for administrative messages in the second example.

> According to FIX 4.4 specification it’s implied that if message gap occurs and one of the counterparties recognizes it and sends ResendRequest message, other counterparty must resend demanded non-administrative messages with PossDupFlag = Y and also it must transmit administrative messages as SequenceResets (GapFill)
> 
> So what is the correct behavior when other counterparty sends demanded non-administrative messages without PossDupFlag=Y ?  
> Should we process it as usually do? Should we reject it or something?
> 
> Example:
> 
> A: 35=0, 34=100  
> B: 35=0, 34=200  
> A: 35=D, 34=110   
> B: 35=2, 34=201, 7=101, 16=109  
> A: 35=D, 34=101, 43 isn’t presented   
> B: ???
> 
> I’m also interested how administrative messages should be processed in this case.
> 
> Example:
> 
> A: 35=0, 34=100  
> B: 35=0, 34=200  
> A: 35=D, 34=110   
> B: 35=2, 34=201, 7=101, 16=109  
> A: 35=1, 34=101   
> B: ??? (should we send Heartbeat?)
> 
> Thanks for any help.