Subject: Re: comments/questions for Subscriber Management MIB

From: Wilson Sawyer <[email-masked]>
Date: Mon, 28 Feb 2000 08:53:00 -0500

Minnie - thanks for the comments. Replies interspersed.

At 08:25 PM 2/23/00 -0800, Minnie Lu wrote:
>Hi,  
>
> I have some comments/questions for Subscriber Management MIB 
>(draft-ietf-ipcdn-subscriber-mib-00.txt) and appreciate any help in advance 
>! If any of them are discussed before, sorry to repeat them and would 
>appreciate letting me know the result.
>
>  1.  In MIB module description, it says :"This will be rooted in 
>experimental space with future transition to be incorporated into the cable 
>device MIB." This MIB is in the MUST list of DOCSIS1.1 OSSI draft spec for 
>CMTS.  When will it happen and have a real root ? 

I don't have a good answer for you. Mike?

>  2. docsSubMgtCpeControlMaxCpeIp has the range (0..16).  To me, this 
>implies that the max CPE IP in the provisioning object is 16.  But, CPE IP 
>can be "learned", so
>   a) if the docsSubMgtCpeControlActive is true, the number of entries in  
>docsSubMgtCpeIpTable could NOT be more than docsSubMgtCpeControlMaxCpeIp 
>which max is16. Right ?
>   b) if the docsSubMgtCpeControlActive is false, the number of entries in 
>docsSubMgtCpeIpTable could be more than 16. Right ?
>   c) Since docsSubMgtCpeControlActive is RW, if a user set it to false from 
>true, and at that moment, there are more than 16 entries in 
>docsSubMgtCpeIpTable already, does it mean no more learned CPE IP ? But the 
>existing CPE IP are still kept in the table, right ?

I would answer that (a), (b), and (c) are correct as you've stated. In the next
draft, the limit of '16' will be removed from the mib.
Your interpretation of (d) is reasonable, but maybe getting into
implementation 
detail. Do you think we need to state this in the MIB?

> 
> 3. comment: docsSubMgtCpeControlLearnable:  
>   a) "If this is set to true, up to MaxCpeIp Address are learned related to 
>this CM."  Would it be better to say "If this is set to true, up to number 
>of docsSubMgtCpeControlMaxCpeIp Address can be learned related to this
CM." ?  

Your wording is probably clearer, but is there a substantive point that I'm
missing?

>   b) Also please add explanation of "learned" (what does it mean 'learned' 
>?) since in the MIB definition, this is the first time the word 'learn' is 
>mentioned. 
>   c) What if this is set to false ?  Please explain more for false condition.

Acknowledged. will address in next draft. We don't want to go too far, though,
in defining 'learned', since we want to leave open a variety of learning
mechanisms at the CMTS.

> 4.  docsSubMgtPktFilterIndex: in the description of 
>docsSubMgtPktFilterTable, it says that "no more than 20 classifiers",  does 
>it mean the FilterIndex is 1 .. 20 ? Need a range for it ?

will be fixed in next draft. The limit has been removed per Guenter's
suggestion.

> 5. docsSubMgtCmFilterDownstream (same for docsSubMgtCmFilterUpstream) could 
>be set to the default which could be 0 upon the initial CMTS
initialization.   
>  a) What does it mean for the value 0 here ?   
>  b) Also it is RW, could a user set the value to 0 on purposely ?
>(Same questions for docsSubMgtCmFilterDownDefault and 
>docsSubMgtCmFilterUpDefault).

I'll look at this. 

>  Thanks a lot for your help again in advance !
>  Minnie 
> 
> 

Wilson Sawyer       [email-masked]
Arris Interactive       (978) 946 4711
6 Riverside Drive      fax (978) 946 4900
Andover, MA 01810

---

From: "Mike St. Johns" <[email-masked]>
Date: Mon, 28 Feb 2000 14:10:52 -0800

> >CMTS.  When will it happen and have a real root ?

I'm going to stick it under the old Cable Device MIB OID tree.  I'm waiting 
on assigning it until we get enough consensus that I don't have to deal 
with having to do the formal MIB change things (e.g. having to deprecate 
objects, obsolete them, etc so that OIDs don't get duplicated).

> >docsSubMgtCpeIpTable could NOT be more than docsSubMgtCpeControlMaxCpeIp

No.  MaxCpeIp applies to learned entries only.  If you're already at max or 
above, you can't learn any more, but you can have your table entry modified 
to add new addresses.  The reason you can't have more than 16 entries is 
because the index value of docsSubMgtCpeIpTable (e.g. the Index value) is 
(1..16)

> >docsSubMgtCpeIpTable could be more than 16. Right ?

Nope - see above.  The index range for the table controls this.

> >existing CPE IP are still kept in the table, right ?

Right.  Except that 16 is the max.

>draft, the limit of '16' will be removed from the mib.

Hmm?  Index objects are required to have a range value.  Do you want to 
change the range?

>Your wording is probably clearer, but is there a substantive point that I'm

I think her point is one implies you can learn N addresses, the other 
implies you can learn N - currentNumAddresses.  E.g. if you've got 5 
addresses already that have been SET (rather than learned), then you can 
still learn N addresses even if N is less than 5.  I'd suggest changing to 
her language to keep the questions down.

>in defining 'learned', since we want to leave open a variety of learning

Actually, I don't think we want to leave this open.  I'd rather make it 
clear we mean you learn based on the source addresses of the IP packets 
sent upstream from any given modem.

>will be fixed in next draft. The limit has been removed per Guenter's

*sigh* Indexes require a range.  I don't mind making it larger than 20, but 
that was also a minimum.

> >docsSubMgtCmFilterUpDefault).

You can set the object to any valid value.  However, that value might not 
map to a given filter set.  By SNMP definition, the filter set can't have 
an index with a value of 0 so the default of 0 means it matches no filters.