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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] RE: iSCSI - long key valuesStephen, We don't want regular values to extend beyond 255 bytes (no good reason to allow this). As such we have 2 limits a) the value length limit AND b) the text block limit. I am not sure that we have to worry about the text block limit except if we are forced into shorter blocks by the framing mechanism. The block spanning mechanism enables us to avoid the first limit (and even here we don't have a good mechanism as bookmarks are target driven and we have to invent another mechanism for initiator driven bookmarks. It looks like the second solution I've suggested works in both directions and is "scalable" while the first needs an additional mechanism to scale beyond a block. Julo "Wheat, Stephen R" To: Julian Satran/Haifa/IBM@IBMIL, <stephen.r.wheat@ ips@ece.cmu.edu intel.com> cc: Subject: RE: iSCSI - long key values 19-09-01 18:06 Please respond to "Wheat, Stephen R" Julian, Maybe I'm missing something, but I think the new "value extension" discussion is around how to send very long "values" in a list of key=value pairs. IF we may have key=value pairs arbitrarily span PDUs, then the sending of a long value is done simply by sending one text response PDU after another, some may have nothing but a 4KB "value" component of a key=value pair. The concatenation of the individual "value" components is then done on the Initiator side, through the process of concatenating the text responses (in order, of course). So, am I missing something here? Stephen -----Original Message----- From: Julian Satran [mailto:Julian_Satran@il.ibm.com] Sent: Tuesday, September 18, 2001 9:31 PM To: ips@ece.cmu.edu Subject: RE: iSCSI - long key values Stephen, It is still on the "to consider list". How would that affect the individula value "extension" that we are considering now? Julo "Wheat, Stephen R" <stephen.r.wheat@intel.com> on 18-09-2001 17:57:36 Please respond to "Wheat, Stephen R" <stephen.r.wheat@intel.com> To: Julian Satran/Haifa/IBM@IBMIL, ips@ece.cmu.edu cc: Subject: RE: iSCSI - long key values Julian, Almost a month ago, we had a thread on values spanning PDU boundaries. See: "Re: Target record not to span PDUs?" Anyway, that thread discussion ended without conclusion. I believe Robert Snively's and my proposal to allow records to span PDUs is still valid; I'll let Robert speak for himself. Furthermore, I believe that the proposal would thus avoid this problem you are now addressing, with far less complexity. Please reconsider this proposal. Stephen -----Original Message----- From: Julian Satran [mailto:Julian_Satran@il.ibm.com] Sent: Monday, September 17, 2001 11:26 PM To: ips@ece.cmu.edu Subject: iSCSI - long key values Dear colleagues, Ofer brought recently to my attention that some security key values are likely to exceed our stated limit of 255 bytes for a value. A good example may be a certificate (or chained certificate). We have to enable those to be in the Login phase. To handle this we might want to consider the following options (but not only those): enable a "long hexadecimal coding" that should indicate a "long" value (e.g. use 0L instead of 0x) and raise the limit for those keys to something longer (say 3072 bytes?) enable "concatenated" values and indicate them through a "coding scheme" as follows: the value "0sxx" indicates a name suffix (as in "key = 0s08" means that the keys "key00" , "key01" etc) have to be concatenated use the "suffixed keys" to "build the value" use a named key coding (as in "0Nname" in a value means that you have to use later get=value to get a "binary response" containing the whole binary object) I think that option 2 (limited to a 3 digit prefix?) covers well what we need and offers some extension space and option 1 is probably good enough for certificates. Comments? Julo
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