queries Regarding Transport layer

George Penokie gop at us.ibm.com
Wed Jul 5 12:28:21 PDT 2006

Formatted message: <A HREF="r0607055_f.htm">HTML-formatted message</A>

The answer to your question is found in section 
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, 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 
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 at us.ibm.com
Internal:  553-5208
External: 507-253-5208
sandeep taneja <sandeep.taneja at mail.nsysinc.com> 
Sent by: owner-t10 at t10.org
06/30/2006 02:33 AM
t10 at t10.org
Mark_Evans at maxtor.com
queries Regarding Transport layer
* From the T10 Reflector (t10 at t10.org), posted by:
* sandeep taneja <sandeep.taneja at 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
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.
Sandeep Taneja
nSys Design Systems
Accelerating designs
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