RE: rap-sppi-02 EXTENDS clause instance mapping??

["Rawlins, Diana" <Diana.Rawlins@wcom.com>]

Juergen,

I've look closely at section 8.8 as well as the Framework PIB and COPS-PR
documents.  It must be a case of  "seeing but not understanding!" 

So does the PDP specify an EXTENDs policy using two bindings? The first
binding installs the base row policy instance and the second binding
installs the EXTEND's policy instance. The PRID of the second binding is
constructed using the PRC OID of the EXTENDs table object and the instance
ID of the base instance as the last sub-identifier. Is that how to
accomplish the mapping EXTENDS policy is installed?

Is it true that a base row instance is not reused by multiple EXTENDS
instances? For example the same BaseFilterTable would NOT be reused for an
IPFilterTable PRI and an 802FilterTable PRI. ??

If the above is the correct understanding, I think more clarification either
in the SPPI or COPS-PR would be useful. Does anyone else agree?

Thanks!
-Diana


-----Original Message-----
From: Juergen Schoenwaelder [mailto:schoenw@ibr.cs.tu-bs.de]
Sent: Thursday, October 26, 2000 5:32 AM
To: Rawlins, Diana
Cc: rap@ops.ietf.org
Subject: Re: rap-sppi-02 EXTENDS clause instance mapping??



>>>>> Rawlins, Diana writes:

Diana> How is an EXTENDS instance related / associated with a specific
Diana> base instance? For example how is an instance of the
Diana> frwkIpFilterTable map to the appropriate instance of
Diana> frwkBaseFilterTable?

The instance of the frwkIpFilterTable and the appropriate instance of
the frwkBaseFilterTable share the same instance identifier. EXTENDS
basically works like AUGMENTS with the following difference: The
EXTENDS does not require that there is an instance in the extending
table for each instance in the base table. In other words, an AUGMENTS
is a 1:1 relationship while EXTENDS is an 1:0..1 relationship.

Diana> I'm not seeing any description of the mechanism associating an
Diana> extends instance and its base instance in the SPPI and/or the
Diana> Framework Policy Information Base draft -- maybe I'm seeing and
Diana> not understanding ;-)

I think section 8.8 of the latest SPPI draft contains the answers.

Diana> Also, can an EXTENDS PRC be specified as the base for another
Diana> EXTENDS PRC?

Yes. This is stated in the last sentence in the 2nd paragraph of
section 8.8 in the SPPI document.

/js

-- 
Juergen Schoenwaelder      Technical University Braunschweig
<schoenw@ibr.cs.tu-bs.de>  Dept. Operating Systems & Computer Networks
Phone: +49 531 391 3289    Bueltenweg 74/75, 38106 Braunschweig, Germany
Fax:   +49 531 391 5936    <URL:http://www.ibr.cs.tu-bs.de/~schoenw/>