Re: [Teas] WG adoption poll: draft-bestbar-teas-ns-packet-08

[Loa Andersson <[e-mail]>]

Tarek,

Inline please.

On 2022-02-28 12:38, Tarek Saad wrote:
> Hi Zhibo,
> 
> See inline.
> 
> *From: *Teas <[e-mail]> on behalf of Huzhibo 
> <huzhibo=[e-mail]>
> *Date: *Friday, February 25, 2022 at 8:03 PM
> *To: *Vishnu Pavan Beeram <[e-mail]>, Ogaki, Kenichi 
> <[e-mail]>
> *Cc: *Lou Berger <[e-mail]>, TEAS WG Chairs 
> <[e-mail]>, [e-mail] 
> <[e-mail]>, TEAS WG <[e-mail]>
> *Subject: *Re: [Teas] WG adoption poll: draft-bestbar-teas-ns-packet-08
> 
> Hi:
> 
> I would appreciate it if the authors can clarify the following questions:
> 
> 1.   Essentially the identifier in data packet is used to identify the 
> NRP which the packet is mapped to, and the set of resource for 
> processing and forwarding the packet. Calling it a flow aggregate 
> selector would confuse the boundary between service flows and the 
> underlay network construct (which is called NRP). In my understanding, 
> the network devices only maintain the NRP specific resource states, they 
> (except the ingress nodes) do not need to know whether and how service 
> flows are mapped to the NRP.
> 
> [TS]: service flows (from IETF network slices) are aggregated into Slice 
> Flow-Aggregate (SFA) so they are given similar treatment in the network. 
> The flow aggregate traffic carries a Flow-Aggregate Selector (FAS) to 
> allow nodes to distinguish packets belonging to the SFA. The SFA traffic 
> is placed on paths established over the network resources defined by the 
> NRP.

Are you saying that SFA's have the same FEC? If so are we inventing the 
wheel again?

/Loa
> 
> 2.   I’m a little confused about the case which multiple VPN labels are 
> used to identify a Slice Flow Aggregate. The VPN service label are 
> usually called service label, it is not clear how a service label can be 
> used to identify a flow aggregate. And since this data plane ID need to 
> be processed by intermediate nodes, can the VPN labels be parsed and 
> processed by the intermediate nodes? BTW, the text in section 5.1.1 
> describes several options of encapsulating the identifier in MPLS packet 
> header, which does not belong to a TEAS document, better to move them to 
> an MPLS draft.
> 
> [TS]: the document describes that a FAS can take several forms and 
> depending on the specifc dataplane (e.g., MPLS, IPv6, etc.). The use of 
> the service labels was an example for illustration only. The document 
> already references MPLS documents (e.g., I-D.kompella-mpls-mspl4fa and 
> I-D.decraene-mpls-slid-encoded-entropy-label-id) where proposals allow 
> carrying the FAS in the MPLS label stack.
> 
> Regards,
> 
> Tarek (for co-authors)
> 
> Thanks
> 
> Zhibo
> 
> *From:*Teas [mailto:[e-mail]] *On Behalf Of *Vishnu Pavan 
> Beeram
> *Sent:* Thursday, February 24, 2022 11:04 PM
> *To:* Ogaki, Kenichi <[e-mail]>
> *Cc:* Lou Berger <[e-mail]>; TEAS WG Chairs 
> <[e-mail]>; [e-mail]; TEAS WG 
> <[e-mail]>
> *Subject:* Re: [Teas] WG adoption poll: draft-bestbar-teas-ns-packet-08
> 
> Kenichi, Hi!
> 
> Thanks for the review! This draft discusses the use of Network Resource 
> Partition (NRP) to support a Slice-Flow Aggregate. The NRP identifier is 
> unique within an NRP domain and is meant for use in the 
> control/management plane to identify the resources associated with the 
> NRP (this should be the identifier used in any relevant control-plane 
> protocol extensions).
> 
> The NRP-ID is not the same as Flow-Aggregate Selector (FAS). The FAS is 
> quite simply the marking in the data plane packet that identifies a 
> Slice-Flow Aggregate. The same Slice-Flow Aggregate may be identified by 
> multiple Flow-Aggregate Selectors (see the example in Section 5.1.1 
> where a range of VPN service labels – each acting as a FAS – select the 
> same Slice-Flow Aggregate). The solution architecture leaves room for an 
> implementation to overload the NRP-ID and use it as a FAS – but that is 
> strictly an implementation choice.
> 
> And yes, we do expect all other related work to eventually align and 
> adhere to what is specified in this document.
> 
> Regards,
> 
> -Pavan (as co-author)
> 
> On Thu, Feb 24, 2022 at 3:14 AM Ogaki, Kenichi <[e-mail] 
> <mailto:[e-mail]>> wrote:
> 
>     Hi Authors,
> 
>     I'd just like to clarify.
>     Comparing Fig. 5 in draft-ietf-teas-ietf-network-slices-05 with Fig.
>     1 in this draft, I understand that this draft also describes one of
>     solutions realizing Network Resource Partition(NRP).
>     If my understanding is correct, NRP-ID is essentially same as FASL
>     and "Slice Aggregate ID" described at Fig.5 in
>     draft-bestbar-lsr-slice-aware-te-00.
>     >From an operational perspective, it's burden to manage many slice related components and the mappings of these components, e.g. connectivity matrix <-> IETF network slice <-> Slice-flow Aggregate <-> FAS <-> NRP.
>     Do authors have any thought to at least unify these identifiers in a
>     series of bestbar drafts. Or, is there any reason not able to unify
>     these?
> 
>     Thanks,
>     Kenichi
>     -----Original Message-----
>     From: Teas <[e-mail] <mailto:[e-mail]>> On
>     Behalf Of Lou Berger
>     Sent: Friday, February 18, 2022 10:28 PM
>     To: TEAS WG <[e-mail] <mailto:[e-mail]>>
>     Cc: TEAS WG Chairs <[e-mail]
>     <mailto:[e-mail]>>;
>     [e-mail]
>     <mailto:[e-mail]>
>     Subject: [Teas] WG adoption poll: draft-bestbar-teas-ns-packet-08
> 
>     Hello,
> 
>     This email begins a 2-week adoption poll for:
>     https://datatracker.ietf.org/doc/draft-bestbar-teas-ns-packet/
>     <https://datatracker.ietf.org/doc/draft-bestbar-teas-ns-packet/>
> 
>     Please note that IPR has been disclosed on this document:
>     https://datatracker.ietf.org/ipr/search/?submit=draft&id=draft-bestbar-teas-ns-packet
>     <https://datatracker.ietf.org/ipr/search/?submit=draft&id=draft-bestbar-teas-ns-packet>
> 
>     Please voice your support or objections to adoption on the list by
>     the end of the day (any time zone) March 4.
> 
>     Thank you,
>     Lou (as Co-chair)
> 
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-- 
Loa Andersson                        email: [e-mail]
Senior MPLS Expert                          [e-mail]
Bronze Dragon Consulting             phone: [phone]