Subject: Re: [Megaco] Statistics and Move

From: Terry L Anderson <[email-masked]>
Date: Thu, 01 Aug 2002 17:38:39 -0400

This discussion ended in March without specifying the corrections.  But 
I believe that the concensus was that statistics are reported by default 
and reset only when a termination is Subtracted and so ceases to exist 
or is returned to null and NOT when Moved, that is, statistics are a 
property of a termination during its active life and not simply its life 
in a single context.  Several places in H.248.1 the language refers to 
context and so confuses this point.  The following changes attempt to 
make this clear.

6.2: end of the fourth paragraph:
current V2:
    and when the Termination is subtracted from a context.
current V1:
    and when the Termination is taken out of the call it is in.
New for both:
    and when the Termination ceases to exist or is returned to the null 
context due to a Subtract command.

7.1.5:
The Statistics parameter provides information describing the status and 
usage of a Termination during its existence [REPLACE: "within a specific 
Context", WITH: "outside the null context"].  There is a set of standard 
statistics kept for each termination where appropriate (number of octets 
sent and received for example).  The particular statistical properties 
that are reported for a given Termination are determined by the Packages 
realized by the Termination.  By default, statistics are reported when 
the Termination [REPLACE: "is Subtracted from the Context", WITH: 
"ceases to exist or is returned to the null context due to a Subtract 
command".].  This behavior can be overridden by including an empty 
AuditDescriptor in the Subtract command.  Statistics may also be 
returned from the AuditValue command, or any Add/Move/Modify command 
using the Audit descriptor.
Statistics are cumulative; reporting Statistics does not reset them.  
Statistics are reset when a Termination [REPLACE: "is Subtracted from a 
Context", WITH: "ceases to exist or is returned to the null context due 
to a Subtract command"].

and to be consistent:
Annex E.11.4 description of statistic dur:
currently:
    Provides duration of time the termination has been in the context.
change to:
    Provides duration of time the termination has existed or been out of 
the null context.

I believe that this corrects all the references to statistics being 
related to context that occur in H.248.1 including Annexes A-E but I 
have not yet checked for similar cases in other Annexes or packages.

Terry L Anderson wrote:

>Yes, statistics belong to a termination and NOT a context and they are zero'ed
>only by a subtract (which effectively ends a termination, ephemerals go away and
>physicals go to NULL and get default values of all parameters).  Move should not
>change the values of any statistic or parameter (unless it is changed
>explicitely by a descriptor in the command).
>
>We need to find all such wording referring to context and fix it.
>
>Sankar Raman wrote:
>
>  
>
>>Terry:
>>
>>You mentioned that we would accumulate statistics when we
>>Move a termination from one context to another non null context.
>>i.e the stats collected in pevious context gets added.
>>
>>What about the nt package - "Duration"
>>"Description: Provides duration of time the termination has been in context"
>>
>>Is this also cumulative ?? If so, should the text be changed to something
>>like "duration of time termination has been in non null context(s)" ??
>>
>>At 04:23 PM 3/7/02 -0500, Terry L Anderson wrote:
>>    
>>
>>>Statistics on a termination are defined in two ways:
>>>1.     6.2 says:
>>>   "Statistics are reported...when the termination is taken out of the
>>>call it is in."
>>>
>>>2.    7.1.15 says:
>>>   "The Statistics parameter provides information describing the status
>>>and usage of a Termination during its existence with a specific
>>>Context."
>>>
>>>I don't think a "call" is a well defined concept in H.248, but perhaps
>>>these two statements are consistent if we associate a "call" with a
>>>context.  The issue is, if a termination is Moved to a different
>>>termination, is it in the same call (one party is probably the same but
>>>the other may not be)?  Or, more specifically are its statistics
>>>zero'ed.
>>>
>>>Subtract clearly zeros them since ephemerals disappear and physicals get
>>>default values when returned to NULL context, and we state this as the
>>>last sentence in 7.1.15.  The issue is for a Move.  We never clearly
>>>state this for Move, but from the current language defining what
>>>statistics mean, I assume that they ARE zero'ed.  It would help if that
>>>last sentence in 7.1.15 included Move (or if they are NOT cleared, we
>>>state that).
>>>
>>>We report statisics, by default, on a Subtract, but NOT on a Move.  So
>>>if statistics are zero'ed by the move, then one must remember to add a
>>>Statistics Descriptor to Move to get them where this is not needed for a
>>>Subtract.  It would seem to be consistent we would have reported
>>>statistics by default on all commands that zero them rather than only on
>>>Subtract.
>>>
>>>--
>>>
>>>------------------------------------------------------------
>>>Terry L Anderson              <mailto:[email-masked]>mailto:[email-masked]
>>>Tel:908.582.7013   Fax:908.582.6729
>>>Lucent Technologies/INS/Voice Over IP Access Networks
>>>Rm 2B-121, 600 Mountain Av, Murray Hill, NJ 07974
>>><http://its.lucent.com/~tla>http://its.lucent.com/~tla (Lucent internal)
>>>      
>>>
>><http://www.gti.net/tla>http://www.gti.net/tla
>>    
>>
>>>
>>>      
>>>
>
>--
>
>------------------------------------------------------------
>Terry L Anderson              mailto:[email-masked]
>Tel:908.582.7013   Fax:908.582.6729
>Lucent Technologies/INS/Voice Over IP Access Networks
>Rm 2B-121, 600 Mountain Av, Murray Hill, NJ 07974
>http://its.lucent.com/~tla (Lucent internal) http://www.gti.net/tla
>
>  
>

-- 

------------------------------------------------------------
Terry L Anderson              mailto:[email-masked]
Tel:732.949.5628   Fax:732.949.7016
Lucent Technologies/INS/Voice Over IP Access Networks
Rm 2G-219A, 101 Crawfords Corner Rd, Holmdel, NJ 07733-3030
http://its.lucent.com/~tla (Lucent internal) http://www.gti.net/tla

_______________________________________________
Megaco mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/megaco

---

From: Terry L Anderson <[email-masked]>
Date: Thu, 01 Aug 2002 17:38:39 -0400

7.1.5:

and to be consistent:

--

---

From: Christian Groves <[email-masked]>
Date: Fri, 02 Aug 2002 10:27:14 +1000

G'Day Terry,

Please see my comments below.

Regards, Christian

> context due to a Subtract command.

[CHG] OK

> Context", WITH: "outside the null context"].  There is a set of standard

[CHG] "Outside the null context" is not correct for euphemeral terminations. Why
not just strike "within a specific context"?

> Context", WITH: "ceases to exist or is returned to the null context due

[CHG] OK

> have not yet checked for similar cases in other Annexes or packages.

[CHG] OK

---

From: Christian Groves <[email-masked]>
Date: Fri, 02 Aug 2002 10:27:14 +1000

G'Day Terry,

Regards, Christian

[CHG] OK

[CHG] OK

[CHG] OK

---

From: Terry L Anderson <[email-masked]>
Date: Fri, 02 Aug 2002 09:57:08 -0400

See below

>not just strike "within a specific context"?
Well, I'm trying to insure the language covers both cases, but perhaps 
my choice still wasn't perfect.  Just striking it, might make it appear 
that it continues even after a physical termination returns to null, 
since it really still "exists".  That's why said "outside the null 
context".  I believe that even ephemerals are "outside the null context" 
they are just never "inside", but I am open to other wording such as:
    "...during its existence (ephemeral) or while it is outside the null 
context (physical)."

Do we have another issue here?  What is the proper behavior if 
statistics are requested of a termination IN the null context?  From 
this description it would appear that it has none.  I do not see a 
proper error code.  Does MG simply return 0 for all statistics?

--

---

From: Terry L Anderson <[email-masked]>
Date: Fri, 02 Aug 2002 09:57:08 -0400

See below

--

---

From: Christian Groves <[email-masked]>
Date: Mon, 05 Aug 2002 12:03:25 +1000

G'Day Terry,

I think your updated text is an improvement.

I'm not sure statistics are something that should be counted in a NULL context.
Certainly you can't rely on a subtract from the NULL context returning
statistics.... its not allowed.

Regards, christian

---

From: Christian Groves <[email-masked]>
Date: Mon, 05 Aug 2002 12:03:25 +1000

G'Day Terry,

Regards, christian