Kevin...
No... there
are not timing requirements in the SAS spec to limit how long an
end device (initiator or target) may reject connection requests with
OPEN_REJECT(RETRY). I think is is the scenario you were asking
about.
There are other conditions which would cause the I_T
Nexus Loss timer to expire, but those of course are generally relative to
not getting the connection request (OPEN frame) actually "routed" to the
intended end device. OPEN_REJECT(RETRY) does not cause I_T Nexus
Loss.
I'll point out that there is an Initiator Response Time
timer defined, but that is limitted to timing how long it is taking an initiator
to provide write data back to a target. If the initiator does not
provide some write data withing this time limit, then the target may start
aborting that command. For more info on this time, check out section
9.2.6.3 of the r14 draft spec.
Also as side note... the addition of the "CONTINUE AWT"
bit is an attempt to help devices contiunue to get their work done when
receiving an OPEN_REJECT(RETRY), so that they don't always go back to lowest
priority.
Brian Day
LSI Corporation
Is there any requirements related to
how long it can take to allow an OPEN when in the middle of a SCSI
transfer?
e.g., Read command
target tries to OPEN a connection with the
initiator port to transfer a frame. The initiator port doesn't accept the
OPEN. How long is can the initiator port not accept the OPEN (e.g., to
perform flow throttling)?
Thanks,
Kevin D. Butt
SCSI
& Fibre Channel Architect, Tape Firmware
MS 6TYA, 9000 S. Rita Rd.,
Tucson, AZ 85744
Tel: 520-799-2869 / 520-799-5280
Fax: 520-799-2723
(T/L:321)
Email address:
kdbutt@us.ibm.com
http://www-03.ibm.com/servers/storage/