3 Replies Latest reply on Apr 16, 2017 8:02 PM by nikhiljain

    RNR NAK clarification

    nikhiljain

      Hello Experts,

       

      It is wriiten in IB specs that " the responder may return an RNR NAK for any type of request (e.g. SEND, RDMA READ request, RDMA WRITE request, etc.).", so does that mean responder can return RNR NAK for any SEND FIRST,SEND MID or it can send RNR NAK for SEND LAST only?

      Please clairfy

       

      Thanks

      Nikhil Jain

        • Re: RNR NAK clarification
          idant
          This message was posted by Idan Touito on behalf of Martijn van Breugel

          Hi Nikhil,

           

          Thank you for posting your question on the Mellanox Community.

           

          I am reviewing the information you have provided and will get back to you as soon as possible.

           

          Thanks and regards,

          ~Mellanox Technical Support

          • Re: RNR NAK clarification
            idant
            This message was posted by Idan Touito on behalf of Martijn van Breugel

            Hi Nikhil,
            As mentioned in section 9.7.5.2.8 of the IB Specification Vol 1.
            "The responder may return and RNR NAK for any type of request e.g. SEND, RDMA READ request, RDMA WRITE request, etc.) not limited to any SEND FIRST, MID or LAST"

            But on receiving the RNR NAK only the same precise request can be send.

            Hope this answers your question.

            Thanks and regards,
            ~Mellanox Technical Support

              • Re: RNR NAK clarification
                nikhiljain

                Hi,

                 

                Clarification from your reply, in IB specs request is WQE and then this request is break in to packets like FIRST,MID or LAST according to PMTU, so my thinking is that queue having work elements will reply with RNR NAK only when full request got completed rather than on FIRST, MID or LAST packets.

                 

                Please let me know if I am thinking in wrong direction, need you valuable suggestion on this

                 

                Thanks

                Nikhil Jain