iSCSI: use of Text/Login with no data segment

[pat_thaler@agilent.com]

Julian,

4.2 (page 72) of iSCSI-13 says:
A target or initiator SHOULD NOT use a Text/Login Response or Text/
Login Request with no data segment (DataSegmentLength 0) unless
responding to a Text/Login Request respective Text/Login Response
with the C bit set to 1.

"SHOULD NOT" is too strong here as there are times when one must send a
Text/Login Response or Request with no data segment if one is to complete
the login.

For example, a Target might send a Login response with the T=0 and C=0. If
the initiator doesn't have an keys it wants to send, then the initiator will
have to send a Login Request with no data segment if the login is to
complete.

Also, wrt grammar, "respective" is not a conjunction so the normal way to
use it would be "... A or B ... C or D, respectively, ...." At least that is
the usage that I have seen and what the dictionary at hand supports.

If one wants to retain the idea of not sending empty PDUs when you do have
something to say, one could put in:
A target or initiator SHOULD NOT use a Text/Login Response or Text/
Login Request with no data segment (DataSegmentLength 0) unless
responding to a Text/Login Request or Text/Login Response, respectively,
with the T bit set to 0 while the node has no keys to send or with the C bit
set to 1.

Pat