Re: iSCSI: Aggregation tags in SendTargets

[Mark Bakke <mbakke@cisco.com>]

Kevin-

I think that a numeric tag would be simpler as you had said.
Marjorie had asked for the alpha-numeric tag; anyone needing
more than a numeric tag, please speak up.  I don't have any
particular opinion either way.

If nobody requires alpha-numeric tags, I will change it to
a simple numeric tag.  Otherwise, I'll update the examples.

So,

   ***    Anyone need Numeric Aggregation Tags    ***

                   Going once....

--
Mark

Kevin Gibbons wrote:
> 
> Mark,
>         in the proposed change to the NDT document, you state that the
> aggregation "tag" is an ASCII, alpha-numeric string.  I read this to mean
> the tag can be any string value.
> 
>         Could you make the aggregation tag be a numeric string, indicating
> an aggregation group?  This would align with your example, and should make
> it easier to quickly index portals into different groups.
> 
>         Regards, Kevin
> 
> -----Original Message-----
> From: Mark Bakke [mailto:mbakke@cisco.com]
> Sent: Tuesday, May 15, 2001 1:06 PM
> To: IPS
> Subject: iSCSI: Aggregation tags in SendTargets
> 
> During the interim meeting, we had discussed a proposal to
> add an aggregation tag to the SendTargets response, indicating
> which (if any) target addresses supported multiple connections
> per session, and which groups of addresses an initiator could
> hope to aggregate a session across.
> 
> Aggregation tags were generally well-received; a small modification
> to the proposed method also allows an initiator to know whether
> a single address supports multiple connections per session just
> by itself.
> 
> Here is the section that would go into the NDT document.
> 
> --
> 
> (This would be added to section 4.2, right before the vendor-specific
> paragraph at the end):
> 
>   If an iSCSI target supports multiple connections per session,
>   it must indicate this by including an aggregation tag after each
>   address, in the form of
> 
>     TargetAddress=address,tag
> 
>   Where "tag" is an ASCII, alpha-numeric string indicating an address
>   group.  Within a single session, a connection may be requested to any
>   combination of TCP addresses that have the same tag.  If an address
>   supports multiple connections per session, but does not support
>   spanning a session across other addresses, it will have its own
>   tag.
> 
>   Here is an example:
> 
>     TargetName=fqn.com.acme.diskarray.sn.8675309
>     TargetAddress=10.1.0.45:3000,1
>     TargetAddress=10.1.1.46:3000,1
>     TargetAddress=10.1.0.47:3000,2
>     TargetAddress=10.1.1.48:3000,2
>     TargetAddress=10.1.1.49:3000
>     TargetAddress=10.1.1.50:3000,3
>     TargetAlias=Oracle tables
> 
>   In this example, any of the target addresses can be used to reach
>   the same target.  A single-connection session can be established
>   to any of these TCP addresses.  A multiple-connection session could span
>   addresses .45 and .46, or .47 and .48, but cannot span any other
>   combination.  A TargetAddress without a tag (.49) cannot be combined
>   with any other address within the same session.  A TargetAddress
>   with a tag that is not shared with other addresses supports multiple
>   connections per session, but all connections must be to the same
>   address.
> 
>   To make this work, there are a few rules to follow:
> 
>   A target that does not support spanning sessions across multiple addresses
>   MUST NOT include the tags.
> 
>   A target that is accessible via multiple TCP addresses SHOULD include
>   all TCP addresses in a SendTargets response.
> 
>   A target with multiple TCP addresses that supports a session spanning
>   multiple TCP addresses MUST indicate TCP address groups using aggregation
>   tages in a SendTargets response.
> 
>   Aggregation tags have no meaning or persistence beyond a particular
>   SendTargets response.
> 
> --
> Mark A. Bakke
> Cisco Systems
> mbakke@cisco.com
> 763.398.1054

-- 
Mark A. Bakke
Cisco Systems
mbakke@cisco.com
763.398.1054