To: sandeep taneja <sandeep.taneja@mail.nsysinc.com> Cc: t10@t10.org Subject: Re: queries Regarding Transport layer From: George Penokie <gop@us.ibm.com> Date: Wed, 5 Jul 2006 14:28:21 -0500 X-Message-Number: 7021 Formatted message: HTML-formatted message Sandeep, The answer to your question is found in section 9.2.6.2.3.3 ST_ITS2:Initiator_Send_Frame state. The following paragraph, from that section, has the answer: "If the confirmation is not Transmission Status (Frame Transmitted) or Transmission Status (I_T Nexus Loss) (see table 122 in 8.2.2.3.4), and the Transmit Frame request was for a COMMAND frame or a DATA frame, then this state shall send a Transmission Complete (Command Failed, Connection Failed) message to the ST_IFR state machine. The message shall include the tag." To answer your specific question (as stated in the above paragraph from SAS-2 rev 4a) The ST_ITS state machine notifies the ST_IFR state machine by sending a Transmission Complete (Command Failed, Connection Failed) message to the ST_IFR state machine if NAK or ACK/NAK timeout occurs. It does not matter if the lost DATA frame occurs as part of the first burst data or not, as the first burst is nothing more than an amount of initial write data that the target and initiator have prearranged to transfer before a real XFER_RDY occurs. But the error rules are no different whether the first data is transferred as a result of an actual XFER_RDY or an implied XFER_RDY. Bye for now, George Penokie Dept 9A8 030-3 A410 E-Mail: gop@us.ibm.com Internal: 553-5208 External: 507-253-5208 sandeep taneja <sandeep.taneja@mail.nsysinc.com> Sent by: owner-t10@t10.org 06/30/2006 02:33 AM To t10@t10.org cc Mark_Evans@maxtor.com Subject queries Regarding Transport layer * From the T10 Reflector (t10@t10.org), posted by: * sandeep taneja <sandeep.taneja@mail.nsysinc.com> * Hello !! Could anybody help me for solving some doubts in Transport layer. I have few doubts regarding implementation of Transport layer state machines. I am referring to SAS2r03a 22 April 2006. Following are queries : 1.How does ST_ITS state machine notify ST_IFR state machine that NAK or ACK/NAK timeout have occurred for DATA frame corresponding to first enable burst.Is it going to use same message as it is using for the DATA frame corresponding to XFER_RDY frame? if yes, then message( Transmission complete(Data-out failed,NAK received)corresponding to NAK & message Transmission complete(Data-out failed,ACK/NAK Timeout)) ST_ITS uses to notify ST_IFR is given but How ST_IFR will handle these message or notify Application layer about data sending failure seems to be missing. Thanks. -- -------------------------------------------- Regards Sandeep Taneja nSys Design Systems Accelerating designs http://www.nsysinc.com -------------------------------------------- * * For T10 Reflector information, send a message with * 'info t10' (no quotes) in the message body to majordomo@t10.org