Subject: Re: [NSIS] Review of draft-ietf-nsis-qspec-18.txt

From: "TARAPORE, PERCY S, ATTLABS" <[email-masked]>
Date: Fri, 22 Feb 2008 11:44:43 -0600

The purpose and intent for Y.2171 was to standardize a set of admission control priority levels that can be recognized across multiple admin domains - and acted upon appropriately to provide the necessary CAC within each domain. Further, Priority Level 1 - the highest CAC priority - is exclusively reserved for emergency telecommunications in Y.2171. Thus retaining these in the NSIS-QSPEC is appropriate. They should not be changed or removed.
 
Percy S. Tarapore

________________________________

From: [email-masked] [mailto:[email-masked]] On Behalf Of Gerald Ash
Sent: Thursday, February 21, 2008 11:56 AM
To: Francois Le Faucheur IMAP; Martin Stiemerling; [email-masked]; nsis
Cc: [email-masked]
Subject: Re: [NSIS] Review of draft-ietf-nsis-qspec-18.txt

Francois, Martin, John, All,
 
>>> o Regarding Admission Priority:
>>> * every protocol spec will only indicate that "higher value
>>> means higher priority".
>>> * there is no attempt to define what specific values should
>>> be used for what. this is left outside the scope of the
>>> protocol specs.
>>> * each protocol spec will add a statement clarifying that a
>>> given Admission Priority is to be encoded with the same
>>> value in each of the three protocol spec. For example, in
>>> tsvwg-emergency-rsvp, under section 3.1. we will add:
>>> " A given Admission Priority is encoded in this information
>>> element using the same value as when encoded in the
>>> Admission Priority parameter defined in section 6.2.9 of
>>> [nsis-qspec], or in the Admission Priority parameter
>>> defined in section 4.10 of [dime-qos-parameters].
>>> In other words, a given value in any of the
>>> [emergency-rsvp] Admission Priority information element,
>>> the [nsis-qspec] Admission Priority parameter or the
>>> [dime-qos-parameters] Admission Priority parameter,
>>> refers to the same Admission Priority.
 
>> The above proposed paragraph is really unclear.  Which draft
>> is setting up IANA Registries to assign Admission Priority
>> parameters?  The way it reads it sounds like all three drafts
>> are setting up registries but that somehow (magically) all refer
>> "to the same Admission Priority".  How can that be if they
>> assign different values?  Right now emergency-rsvp and
>> nsis-qspec set up registries for Admission Priority and
>> dime-qos-parameters is using the nsis-qspec registry as I
>> recall.
>>
>> Please clarify the proposal as to which draft is setting up a
>> registry for Admission Priority. 

> No registry is setup.
> It is up to a network administrator to decide how many/which
> admission priority gets used for what. This is similar to how
> Preemption is used (ie each network administrator may decide 
> to use it or not, may decide to use 2,3,4,...128,.. levels...).
> The statement above only says that the the same value of 
> admission priority should be used in the three protocols to refer 
> to same level of admission priority.
 
That's a fundamental change to NSIS/QSPEC and does away with standardized Admission Priority values.  QSPEC is following Y.1571 (now Y.2171 according to An Nguyen) in standardizing 3 priority levels to have end-to-end cross-domain significance.
 
If we elimate this standardization, as is proposed, then different admission priority values can be assigned in different Admin domains, and will have no end-to-end significance.  For example, Admin-domain 1, Admin-domain 2, and Admin-domain 3 assign admission priority=2,  admission priority=4, admission priority=10 for the highest level priority, respectively.  Admin-domain 1 and Admin-domain 2 try to initiate end-to-end flows via Admin-domain 3 for a 'high priority' flow.  However, Admin-domain 3 has no idea how to treat the flow admission priority since all 3 domains are using different encodings of high priority.
 
Admission priority is not the same as preemption priority and should not be based on that model.
 
IMO we should retain the standardized admission priority levels based on Y.1571/Y.2171.  Otherwise, how do we achieve end-to-end, cross-domain standardization of admission priority?  In any case, we need to see some good justification for the change.
 
>> I saw no discussion of this proposed resolution on the NSIS list. 

> which is why we've been assuming there was no issue with it. 
 
It isn't sufficient to declare 'silence is agreement' on making such a fundamental change.  People should weigh in *on the list* and give their technical justifications and confirm their agreement (or disagreement).
 
>> Who were the QSPEC co-authors who worked with you on the
>> proposed resolution?

> Attila, Cornelia and Dave Oran (+ NSIS WG chairs).
 
So far I've not been able to verify agreement from the QSPEC co-authors as yet.  We saw no discussion of the issue on the list, and there needs to be some explanation/justification for the change.  
 
Perhaps Francois could summarize the technical discussion amonst the co-authors, and also state who explicitly agreed (as opposed to who had no comment or active participation in the discussion).  
 
It would be good if the co-authors who participated in the discussion of the 'proposed agreement' could weigh in on the list with their technical view.
 
Also, both NSIS chairs have said there is an agreement on the proposal, so perhaps they could weigh in on the list also with their technical view.
 
Jerry

Francois Le Faucheur IMAP <[email-masked]> wrote:

	Hello Jerry, 

	On 20 Feb 2008, at 16:58, Gerald Ash wrote:

		Francois,
		 
		In your "Proposed Resolution" posting to NSIS on 3 December http://www.ietf.org/mail-archive/web/nsis/current/msg08155.html you say:
		 
		> The Proposed Resolution
		> ===================
		> Co-authors of the three I-Ds as well as WG chairs of the 
		> corresponding WGs converged on the following proposed 
		> resolution. 
		 
		I saw no discussion of this proposed resolution on the NSIS list. 

	which is why we've been assuming there was no issue with it.  

		Who were the QSPEC co-authors who worked with you on the proposed resolution?

	Attila, Cornelia and Dave Oran (+ NSIS WG chairs).

		> o Regarding RPH-Priority:
		> * tsvwg-emergency-rsvp will go ahead with its requests to
		> IANA to provide numerical registry for RPH priority (via 
		> extending existing RPH registry). See IANA Considerations
		> section of tsvwg-emergency-rsvp.
		> * nsis-qspec (in section 6.2.10) will point to this registry
		> instead of defining its own values
		 
		OK.
		 
		> o Regarding Admission Priority:
		> * every protocol spec will only indicate that "higher value
		> means higher priority".
		> * there is no attempt to define what specific values should
		> be used for what. this is left outside the scope of the
		> protocol specs.
		* each protocol spec will add a statement clarifying that a
		> given Admission Priority is to be encoded with the same
		> value in each of the three protocol spec. For example, in
		> tsvwg-emergency-rsvp, under section 3.1. we will add:
		" A given Admission Priority is encoded in this information
		> element using the same value as when encoded in the
		> Admission Priority parameter defined in section 6.2.9 of
		> [nsis-qspec], or in the Admission Priority parameter
		> defined in section 4.10 of [dime-qos-parameters].
		> In other words, a given value in any of the
		> [emergency-rsvp] Admission Priority information element,
		> the [nsis-qspec] Admission Priority parameter or the
		> [dime-qos-parameters] Admission Priority parameter,
		> refers to the same Admission Priority.
		
		The above proposed paragraph is really unclear.  Which draft is setting up IANA Registries to assign Admission Priority parameters?  The way it reads it sounds like all three drafts are setting up registries but that somehow (magically) all refer "to the same Admission Priority".  How can that be if they assign different values?  Right now emergency-rsvp and nsis-qspec set up registries for Admission Priority and dime-qos-parameters is using the nsis-qspec registry as I recall.
		 
		Please clarify the proposal as to which draft is setting up a registry for Admission Priority. 

	No registry is setup.
	It is up to a network administrator to decide how many/which admission priority gets used for what. This is similar to how Preemption is used (ie each network administrator may decide to use it or not, may decide to use 2,3,4,...128,.. levels...).
	The statement above only says that the the same value of admission priority should be used in the three protocols to refer to same level of admission priority.

	Cheers

	Francois

		Also, please provide clearer proposed text to include in the drafts.  
		 
		It would be good to see some discussion of the proposal on the list, to confirm and validate agreement of the WG.
		 
		Jerry

		Francois Le Faucheur IMAP <[email-masked]> wrote:

			Hello,
			
			For memory, the next rev of nsis-qspec is also expected to be aligned 
			with the Resolution of the issue related to QoS Parameters encoding 
			in , & . For 
			convenience, I included below the recap on the corresponding 
			resolution as announced on NSIS, DIME and TSVWG lists.
			
			Just to make sure this does not fall through the cracks.
			
			Cheers
			
			Francois

			>
			> Begin forwarded message:
			>> From: Francois Le Faucheur IMAP 
			>> Date: 3 December 2007 12:05:42 GMT+01:00
			>> To: [email-masked], [email-masked], tsvwg tsvwg 
			>> Cc: Francois Le Faucheur IMAP , David Oran R 
			>> , Hannes Tschofenig , 
			>> ken carlberg , Magnus Westerlund 
			>> , James Polk , 
			>> [email-masked], "(IJ/ETH) Báder Attila" 
			>> , [email-masked], Jukka 
			>> Manner MJ , tsvwg chair 
			>> [email-masked]>, [email-masked], dime- 
			>> [email-masked], "[email-masked]>" 
			>> 
			>> Subject: Resolution of issue QoS Parameters encoding in 
			>> parameters>, & 
			>>
			>> Hello,
			>>
			>> The Issue:
			>> =======
			>> Three different documents (dime-qos-parameters, nsis-qos-nslp, 
			>> tsvwg-emergency-rsvp) need to convey an overlapping set of QoS 
			>> parameters (specifically RPH-Priority and Admission Priority) and 
			>> currently do that in an inconsistent manner. This has been brought 
			>> up and partially discussed on the WG mailing lists.
			>>
			>> The Proposed Resolution
			>> ===================
			>> Co-authors of the three I-Ds as well as WG chairs of the 
			>> corresponding WGs converged on the following proposed resolution. 
			>> Please let us know if you have an issue/concern with this.
			>>
			>> o Regarding RPH-Priority:
			>> * tsvwg-emergency-rsvp will go ahead with its requests to IANA to 
			>> provide numerical registry for RPH priority (via extending 
			>> existing RPH registry). See IANA Considerations section of tsvwg- 
			>> emergency-rsvp.
			>> * nsis-qspec (in section 6.2.10) will point to this registry 
			>> instead of defining its own values
			>> * dime-qos-parameters (in section 4.11) will point to this 
			>> registry instead of defining its own values
			>> * tsvwg-emergency-rsvp (in section 3.2) will keep pointing to 
			>> this registry.
			>>
			>> o Regarding Admission Priority:
			>> * every protocol spec will only indicate that "higher value means 
			>> higher priority".
			>> * there is no attempt to define what specific values should be 
			>> used for what. this is left outside the scope of the protocol specs.
			>> * each protocol spec will add a statement clarifying that a given 
			>> Admission Priority is to be encoded with the same value in each of 
			>> the three protocol spec. For example, in tsvwg-emergency-rsvp, 
			>> under section 3.1. we will add:
			>> " A given Admission Priority is encoded in this information 
			>> element
			>> using the same value as when encoded in the Admission Priority
			>> parameter defined in section 6.2.9 of [nsis-qspec], or in the 
			>> Admission
			>> Priority parameter defined in section 4.10 of [dime-qos- 
			>> parameters].
			>> In other words, a given value in any of the [emergency-rsvp] 
			>> Admission
			>> Priority information element, the [nsis-qspec] Admission Priority 
			>> parameter
			>> or the [dime-qos-parameters] Admission Priority parameter, refers to
			>> the same Admission Priority.
			>> "
			>> * the mirror statement will be added in nsis-qspec (section 
			>> 6.2.9) and dime-qos-parameters (section 4.10)
			>>
			>> Francois
			>>

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