Transport layer retries

Bill Martin bill_martin at sierralogic.com
Tue Aug 9 07:18:30 PDT 2005


* From the T10 Reflector (t10 at t10.org), posted by:
* "Bill Martin" <bill_martin at sierralogic.com>
*
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SAS 1.1 allows for discovery of whether a target supports transport
layer retries, but in the spirit of SCSI, the standard does not require
that the mode page bit be changeable.  In the event that the mode page
bit is not changeable, and the initiator does not support transport
layer retries, what is the mechanism for stopping continuous retries by
the target until a timeout occurs?  The definition of the retry
mechanism in 9.2.4.4.2 and 9.2.4.5.2 require that if retransmitted frame
is received the initiator shall operate on it properly.  Finally, the
number of times that a frame will be retransmitted is vendor specific,
so if the initiator sends NAK, it may be retried over and over.

 

Thanks for any insight.

 

Bill Martin
Sr. Principal Engineer
Standards and Interoperability
Sierra Logic, Inc.
916 772-3658

916 765-6875 (Cell)
bill_martin at sierralogic.com

 


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<p class=3DMsoNormal><font size=3D2 face=3DArial><span =
style=3D'font-size:10.0pt;
font-family:Arial'>SAS 1.1 allows for discovery of whether a target =
supports
transport layer retries, but in the spirit of SCSI, the standard does =
not
require that the mode page bit be changeable.&nbsp; In the event that =
the mode
page bit is not changeable, and the initiator does not support =
transport layer
retries, what is the mechanism for stopping continuous retries by the =
target
until a timeout occurs?&nbsp; The definition of the retry mechanism in =
9.2.4.4.2
and 9.2.4.5.2 require that if retransmitted frame is received the =
initiator
shall operate on it properly.&nbsp; Finally, the number of times that a =
frame
will be retransmitted is vendor specific, so if the initiator sends =
NAK, it may
be retried over and over.<o:p></o:p></span></font></p>

<p class=3DMsoNormal><font size=3D2 face=3DArial><span =
style=3D'font-size:10.0pt;
font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=3DMsoNormal><font size=3D2 face=3DArial><span =
style=3D'font-size:10.0pt;
font-family:Arial'>Thanks for any insight.<o:p></o:p></span></font></p>

<p class=3DMsoNormal><font size=3D2 face=3DArial><span =
style=3D'font-size:10.0pt;
font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=3DMsoNormal><st1:PersonName w:st=3D"on"><font size=3D2 =
face=3DArial><span
 style=3D'font-size:10.0pt;font-family:Arial'>Bill =
Martin</span></font></st1:PersonName><br>
<font size=3D2 face=3DArial><span =
style=3D'font-size:10.0pt;font-family:Arial'>Sr.
Principal Engineer<br>
Standards and Interoperability<br>
Sierra Logic, Inc.<br>
916 772-3658</span></font><o:p></o:p></p>

<p class=3DMsoNormal><font size=3D2 face=3DArial><span =
style=3D'font-size:10.0pt;
font-family:Arial'>916 765-6875 (Cell)<br>
bill_martin at sierralogic.com</span></font><font size=3D2 =
face=3DArial><span
style=3D'font-size:10.0pt;font-family:Arial'><o:p></o:p></span></font></=
p>

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style=3D'font-size:
12.0pt'><o:p>&nbsp;</o:p></span></font></p>

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