Re: iSCSI: synch and steering comments

["Mallikarjun C." <cbm@rose.hp.com>]

>> -I am somewhat confused about the following statement in section 1.2.8.2:
>>     "The Synch and Steering Layer is required to add to every sent data
>>     item (IP packet, TCP packet or some other superstructure) enough
>>     information to enable the receiver to steer it to a memory location
>>     independent of any other piece. "
>> 
>>  Clearly from the way I understood the markers in Appendix.C, it doesn't
>>  comply with this requirement.  A more generic statement would be:
>>     "The Synch and Steering Layer is required to add adequate
>>     information to the data stream to enable the receiver to quickly
>>     steer the stream to its final memory location, even in the face of
>>     discontiguities in the stream. "
>> 
>> +++ Markers are but one example and have only the Synch component. The
>> statement refers to a full steering (RDMA) scheme +++
>
>Julian,
>
>No "full steering (RDMA) scheme" is required. A Sync mechanism that that
>implements framing such that the first item in each frame is an iSCSI header
>is all that is required to enable steering because the iSCSI header contains
>all the required steering information (task tag, data offset).

Exactly my thinking.  Matt is right on.

I think the current statement in the draft I quoted above should be changed
to be more generic to include markers (suggested sentence above), since I 
don't see any reason to exclude markers as a type of synch and steering layer.
In fact, Appendix C is (appropriately) titled "Synch and Steering with Fixed 
Interval Markers".

>
>-Matt


--
Mallikarjun 


Mallikarjun Chadalapaka
Networked Storage Architecture
Network Storage Solutions Organization
MS 5668	Hewlett-Packard, Roseville.
cbm@rose.hp.com