Re: [Teas] network Slice Endpoint in draft-ietf-teas-ietf-network-slice-definition-00

[[e-mail]]

Hi John, all, 

Please some first comments see inline. 

Cheers,
Med

> -----Message d'origine-----
> De : John E Drake [mailto:[e-mail]]
> Envoyé : samedi 3 avril 2021 22:06
> À : BOUCADAIR Mohamed TGI/OLN <[e-mail]>; Joel M.
> Halpern <[e-mail]>; [e-mail]
> Cc : Manish Gupta <[e-mail]>; Kireeti Kompella
> <[e-mail]>
> Objet : RE: [Teas] network Slice Endpoint in draft-ietf-teas-ietf-
> network-slice-definition-00
> 
> Hi,
> 
> As a follow-up to the email, below, that Eric and I sent in late
> February, here is our proposed definition of an IETF Network Slice
> Service:
> 
> 
> IETF Network Slice Service - A service provider instantiates a
> service for a customer which is specified in terms of a set of the
> customer's endpoints (CEs)

[Med] The following text is connectivity-centric. I thought the WG wanted the service to cover other components than connectivity. We should capture this in the definition before we focus on the connectivity component. An easy first fix would be to indicate that CEs are where the service is delivered.     

, a set of connectivity matrices (MP2MP,
> P2MP, MP2P, and P2P) between subsets of these CEs

[Med] I'm afraid this is restrictive. Please refer to https://datatracker.ietf.org/doc/html/rfc7297#section-3.2 for a notion of reachability scope that is more generic than only matrices **between** CEs.   

 and an SLO for each
> CE sending to each connectivity matrix.

[Med] Not sure why there is a restriction to **an** SLO and why this is bound to a "CE sending ...". The connectivity component of a slice may be a receive-only service. There is no sending CE in such case. We need to cover these cases as well. 

  I.e., in a given IETF
> network slice service there may be multiple connectivity matrices of
> the same or different type, each connectivity matrix may be between a
> different subset of CEs, and for a given connectivity matrix each
> sending CE has its own SLO and each SLO may be different.  It is also
> the case that a given sending CE may have a different SLO for each
> connectivity matrix to which it is sending.  Note that a given
> sending CEs's SLO for a given connectivity matrix applies between it
> and each of the receiving CEs for that connectivity matrix.
> 
> This results in the following connectivity matrices:
> 
> 	For a MP2MP connectivity matrix with N CEs, each of the N
> sending CEs has its own SLO and each may be different
> 
> 	For a P2MP connectivity matrix, there is only one sending CE
> and there is only one SLO
> 
> 	For a MP2P connectivity matrix with N CEs, each of the N - 1
> sending CEs has its own SLO and each may be different
> 
> 	For a P2P unidirectional connectivity matrix, there is only one
> sending CE and there is only one SLO
> 
>               For a P2P bidirectional connectivity matrix, there are
> two sending CEs, there are two SLOs, and each may be different
> 
> If an IETF network slice service customer wants to have hub and spoke
> connectivity between N CEs in order to control how traffic is
> distributed between its CEs, it requests a set of N - 1 P2P
> unidirectional connectivity matrices, each between a sending CE spoke
> and the hub CE, and a P2MP connectivity matrix between the sending CE
> hub and the spoke CEs.
> 
> It should be noted that per [RFC4364} section 9
> (https://datatracker.ietf.org/doc/html/rfc4364#section-9) an IETF
> network slice service customer may actually be its own IETF network
> slice service provider in the same or different provider network.
> 
> For a given IETF network slice service, the IETF network slice
> customer and the IETF network slice provider agree, on a per-CE basis
> which end of the attachment circuit provides the service demarcation
> point.  This determines whether the attachment circuit is included in
> any SLOs for the subject CE.
> 
> Yours Irrespectively,
> 
> John
> 
> 
> Juniper Business Use Only
> 
> > -----Original Message-----
> > From: John E Drake
> > Sent: Tuesday, February 23, 2021 9:53 AM
> > To: [e-mail]; Joel M. Halpern
> > <[e-mail]>; [e-mail]
> > Subject: RE: [Teas] network Slice Endpoint in
> > draft-ietf-teas-ietf-network-slice-
> > definition-00
> >
> > Hi,
> >
> > Eric and I have reviewed the Definitions draft, the email thread
> with
> > the subject
> > line: Network Slice Endpoint in
> > draft-ietf-teas-ietf-network-slice-definition-00,
> > and the RFCs referenced in emails on that thread - 3985, 4110,
> 4026,
> > 4664, and 8309, and we would like to propose that in the
> Definitions
> > draft we replace 'network slice endpoint' with 'CE' and 'network
> slice
> > realization endpoint' with 'PE', that we reference  RFCs  3985,
> 4110,
> > 4026, 4664, and 8309, and that we replace the current figure in
> > Endpoint section with several figures, which show connectivity
> > constructs and which are consistent with these RFCs.  We would also
> > like to replace 'consumer' with 'customer', add 'attachment
> circuit',
> > and add a new term, viz, 'IETF Network Slice Service', whose
> > definition is a set of CEs, a set of connectivity constructs
> (MP2MP, P2MP, P2P, etc.) between subsets of these CEs and an SLO for
> each CE sending to each connectivity construct.
> >
> > As an aside, the Endpoint section of the Definitions draft uses the
> > bulk of its prose enumerating what its endpoints are not.  Per
> Yakov,
> > since there are a potentially infinite number of things which its
> > endpoints are not, this is futile and we would like to remove that
> prose.
> >
> > Yours Irrespectively,
> >
> > Eric and John
> >
> >
> > Juniper Business Use Only
> >
> > > -----Original Message-----
> > > From: Teas <[e-mail]> On Behalf Of
> > > [e-mail]
> > > Sent: Tuesday, February 16, 2021 11:59 AM
> > > To: Joel M. Halpern <[e-mail]>; [e-mail]
> > > Subject: Re: [Teas] network Slice Endpoint in
> > > draft-ietf-teas-ietf-network-slice-
> > > definition-00
> > >
> > > [External Email. Be cautious of content]
> > >
> > >
> > > Re-,
> > >
> > > Indeed. That's need to be fixed.
> > >
> > > As we are on the terminology, I do also suggest that the draft is
> > > updated to adhere to RFC8309. Given the recursiveness discussed
> in
> > > the draft, having geo- coordinates interfaces is also confusing.
> > > Inspiring from RFC8309 would make more sense.
> > >
> > > Cheers,
> > > Med
> > >
> > > > -----Message d'origine-----
> > > > De : Joel M. Halpern [mailto:[e-mail]] Envoyé :
> mardi
> > > > 16 février 2021 17:44 À : BOUCADAIR Mohamed TGI/OLN
> > > > <[e-mail]>; [e-mail] Objet : Re:
> [Teas]
> > > > network Slice Endpoint in draft-ietf-teas-ietf-
> > > > network-slice-definition-00
> > > >
> > > > I would be happy to use CE and PE.  I would also be happy to
> use
> > > > completely different words.  The current diagram and
> terminology
> > > > makes this very confusing, and leads to problems.
> > > >
> > > > Yours,
> > > > Joel
> > > >
> > > > On 2/16/2021 11:39 AM, [e-mail] wrote:
> > > > > Re-,
> > > > >
> > > > > Please see inline.
> > > > >
> > > > > Cheers,
> > > > > Med
> > > > >
> > > > >> -----Message d'origine-----
> > > > >> De : Teas [mailto:[e-mail]] De la part de Joel
> M.
> > > > >> Halpern
> > > > >> Envoyé : mardi 16 février 2021 17:12 À : [e-mail] Objet
> : Re:
> > > > >> [Teas] network Slice Endpoint in draft-ietf-teas-ietf-
> > > > >> network-slice-definition-00
> > > > >>
> > > > >> The document is not about the request from the external
> > > > >> customer
> > > > (the
> > > > >> request for the end-to-end network slice). It is about the
> > > > >> request from other orchestration systems to the IETF Network
> > > > >> Slice
> > > > management
> > > > >> systems.
> > > > >
> > > > > [Med] ... which is still behaving as the customer role.
> > > > >
> > > > >   Yes, those systems need to know where they intent to
> > > > >> utilize the IETF network slice.  But the IETF network slice
> > > > >> does
> > > > not
> > > > >> need to know about that.
> > > > >
> > > > > [Med] This is what I fail to see. The orchestrator has an
> > > > > internal
> > > > vision that is not available to the entity asking for a slice.
> > > > These nodes are not even known to the "other orchestration
> > > > systems" when asking for a slice.
> > > > >
> > > > >>
> > > > >> In particular, when we get to talking about configuring the
> > > > >> IETF Network Slice properties, the edge (ingress) that the
> IETF
> > > > >> Network Slice controller controls (and corresponding egress)
> is
> > > > >> what needs
> > > > to
> > > > >> be provisioned.
> > > > >
> > > > > [Med] Agree, but that is a distinct phase.
> > > > >
> > > > > BTW, ingress/egress are as a function of the traffic
> direction.
> > > > > A
> > > > node (PE) may behave as both ingress and egress for the same
> slice.
> > > > >
> > > > >> It is possible that on the egress side there needs to be
> > > > information
> > > > >> about how to deliver the traffic externally.
> > > > >
> > > > > [Med] Agree. That node does not need to be visible (known in
> > > > advance) to the entity that will consume the corresponding
> slice.
> > > > >
> > > > >    But that would not be
> > > > >> in terms of end-points since from the perspective of the
> IETF
> > > > Network
> > > > >> Slice, on the egress that is not an endpoint of anything.
> > > > >
> > > > > [Med] I agree that "endpoint" is confusing. "Customer
> Node/Edge"
> > > > > vs
> > > > "Provider Edge" are my favorite here.
> > > > >
> > > > >>
> > > > >> Yours,
> > > > >> Joel
> > > > >>
> > > > >> On 2/16/2021 11:05 AM, [e-mail] wrote:
> > > > >>> Hi Joel,
> > > > >>>
> > > > >>> I disagree with this note. I do think that both flavors of
> > > > >> "endpoint" should be included in the draft.
> > > > >>>
> > > > >>> >From the customer standpoint, a slice request cannot be
> > > > >> characterized by elements not visible to the customer. The
> > > > >> scope
> > > > of a
> > > > >> requested slice can only be characterized between nodes that
> > > > >> are known to the requestor. This is usually called, CE.
> > > > >>>
> > > > >>> The mapping between a CE and a network device (typically, a
> > > > >>> PE)
> > > > is
> > > > >> a process that is internal to the slice provider.
> > > > >>>
> > > > >>> The CE-PE link cannot be systematically excluded as some
> > > > >>> specific
> > > > >> behaviors may need to be enforced in the CE-PE link. Think
> > > > >> about a slice that is implemented by means of a PE-based VPN
> > > > >> and which requires some specific routing + QoS policies at
> the CE-PE link.
> > > > >>>
> > > > >>> Cheers,
> > > > >>> Med
> > > > >
> > > > >
> > > > >
> > > >
> > >
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Ce message et ses pieces jointes peuvent contenir des informations confidentielles ou privilegiees et ne doivent donc
pas etre diffuses, exploites ou copies sans autorisation. Si vous avez recu ce message par erreur, veuillez le signaler
a l'expediteur et le detruire ainsi que les pieces jointes. Les messages electroniques etant susceptibles d'alteration,
Orange decline toute responsabilite si ce message a ete altere, deforme ou falsifie. Merci.

This message and its attachments may contain confidential or privileged information that may be protected by law;
they should not be distributed, used or copied without authorisation.
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