Resend Request Processing

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Imported from previous forum

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Hi all!

I am referring to Spec. 4.1. I am not sure how to handle the resend requests.

For example a resend request of packets 7-10 is received.
Do I halt sending messages from my outgoing queue to the 2nd party and fulfill the resend request first? and send the rest of the messages which were sent after sequence number 10 previously but before receiving the resend request?

Kindly clarify.

Regards,
Murad.

3

[ original email was from Dean Kauffman - dean.kauffman@tradeweb.com ]
Murad,

Sending Resend Requests and handling the responses should work the same across all 4.n specs. The side receiving the resend request should honor it at the first opportunity and satisfy the request as submitted without being concerned about processing order by the counterparty. Here are two scenarios:

  1. You have sent messages through sequence 15 have dequeued sequence 16 at the time you receive a resend request for 7-10.
    -> 34=15
    <- ResendRequest 7=7 16=10
    -> 34=16
    -> 34=7
    -> 34=8
    -> 34=9
    -> 34=10
    -> 34=17
    Finish sending 16, resend 7-10, then continue with 17 etc. Your counterparty will have queued 11-16 internally to be processed after you fill the gap.

  2. You have sent messages through sequence 15 have dequeued sequence 16 at the time you receive a resend request for 7-infinity. [4.0 and 4.1 use 999999 to represent infinity, 4.2-4.4 use 0.]

-> 34=15
<- ResendRequest 7=7 16=999999
-> 34=16
-> 34=7
-> 34=8
-> 34=9
-> 34=10
-> 34=11
-> 34=12
-> 34=13
-> 34=14
-> 34=15
-> 34=16
-> 34=17
Finish sending 16 , resend 7-16, then continue with 17 etc. Your counterparty will have discarded sequence 11 and beyond waiting for your sequence 7.

> Hi all!
>
> I am referring to Spec. 4.1. I am not sure how to handle the resend requests.
>
> For example a resend request of packets 7-10 is received.
> Do I halt sending messages from my outgoing queue to the 2nd party and fulfill the resend request first? and send the rest of the messages which were sent after sequence number 10 previously but before receiving the resend request?
>
> Kindly clarify.
>
> Regards,
> Murad.
>