Subject: [Adslmib] hdsl2ShdslMIB: SpanConfNumRepeaters & StatusNumAvailRepeaters question

From: Artem Polyakov <[email-masked]>
Date: Sun, 18 Oct 2009 14:53:00 +0700

Hello,

I work on SNMP support for Sigrand devices (www.sigrand.com).

I have a question connected with representation of repeaters in SNMP.
Consider following example: We have a span with
hdsl2ShdslSpanConfNumRepeaters = 6
hdsl2ShdslStatusNumAvailRepeaters = 3

How many repeaters I should represent in tables which use hdsl2ShdslInvIndex
or UnitId as index?

As MIB says in hdsl2ShdslInventoryTable for hdsl2ShdslInvIndex:
*Each entry in this table corresponds to a physical element in an
HDSL2/SHDSL span.  It is based on the EOC unit addressing scheme with
reference to the xtuC.*

So I assume that I have to create entries in tables only for discovered
units. But I need to know for sure.

And there is another related question:
Let's suppose that channel was working with 6 repeaters. Statistics was
accumulated. Then link got down, discovery process started again. The reason
of link down is a damage of segment between SRU3 & SRU4. So now we have a
span with only 3 discovered repeaters (I use STU-C polling only). So if the
answer for the first question is "yes, you need to represent only discovered
units", I have to show only following units: STU-C, SRU1,SRU2,SRU3. But
maybe it is interesting to have access to saved statistics from unavailable
units? Does it consider in MIB or it is not important?

Thank you for your answers.

-- 
С Уважением, Поляков Артем
Best regards, Artem Polyakov

---

From: Scott Baillie <[email-masked]>
Date: Tue, 20 Oct 2009 19:42:22 +1000

Hi Artem,

The answer to your question is in the header section of
RFC4319. I have included the relevant paragraph below.

An hdsl2ShdslSpanInvalidNumRepeaters notification may be generated
following completion of the discovery phase if the number of
repeaters discovered on the line differs from the number of repeaters
specified in hdsl2ShdslSpanConfNumRepeaters.  For those conditions
where the number of provisioned repeaters is greater than those
encountered during span discovery, all table entries associated with
the nonexistent repeaters are to be discarded.  For those conditions
where the number of provisioned repeaters is less than those
encountered during span discovery, additional table entries are to be
created using the default span configuration profile.

Regards,

Scott.

On Sun, 2009-10-18 at 14:53 +0700, Artem Polyakov wrote:
> How many repeaters I should represent in tables which use
> hdsl2ShdslInvIndex or UnitId as index?
> 
> Each entry in this table corresponds to a physical element in an
> reference to the xtuC.
> So I assume that I have to create entries in tables only for
> discovered units. But I need to know for sure.
> 
> Let's suppose that channel was working with 6 repeaters. Statistics
> was accumulated. Then link got down, discovery process started again.
> The reason of link down is a damage of segment between SRU3 & SRU4. So
> now we have a span with only 3 discovered repeaters (I use STU-C
> polling only). So if the answer for the first question is "yes, you
> need to represent only discovered units", I have to show only
> following units: STU-C, SRU1,SRU2,SRU3. But maybe it is interesting to
> have access to saved statistics from unavailable units? Does it
> consider in MIB or it is not important?
> 
> _______________________________________________
> Adslmib mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/adslmib

---

From: Artem Polyakov <[email-masked]>
Date: Tue, 20 Oct 2009 15:59:55 +0700

Forgot to change e-mail again. Sorry

---------- Пересланное сообщение ----------
От: Artem Polyakov <[email-masked]>
Дата: 20 октября 2009 г. 15:58
Тема: Re: [Adslmib] hdsl2ShdslMIB: SpanConfNumRepeaters &
StatusNumAvailRepeaters question
Кому: [email-masked]

Thank you very much, Scott

> > consider in MIB or it is not important?

Should I show saved information about currently unavailable units. It can be
useful.

---

From: Scott Baillie <[email-masked]>
Date: Tue, 20 Oct 2009 20:41:16 +1000

Hi Artem,

According to the previously mentioned paragraph,
you have to discard the rows associated with
unavailable units. The following sentence is relevant :

For those conditions
where the number of provisioned repeaters is greater than those
encountered during span discovery, all table entries associated with
the nonexistent repeaters are to be discarded.

So you must discard the rows associated with the
unavailable units hence you must discard the statistics
otherwise you will not be compliant with RFC4319.

Regards,

Scott.

On Tue, 2009-10-20 at 15:59 +0700, Artem Polyakov wrote:
> Should I show saved information about currently unavailable units. It
> can be useful.
> 
> 
> 
> --

---

From: Artem Polyakov <[email-masked]>
Date: Wed, 21 Oct 2009 10:39:50 +0700

Thank you very much, Scott. It is clear for me now.

2009/10/20 Scott Baillie <[email-masked]>