Re: [Detnet-dp-dt] a quick look at the replication/discarding case for detnet flows

[Loa Andersson <[e-mail]>]

Balazs,

Short responses in-line.

On 2017-01-17 23:26, Balázs Varga A wrote:
> Hi Loa,
>
> Two comments/discussions points for the weekly call:
>
> 1, P nodes (recognizing detnet-flows)
> P nodes have to recognize detnet-flows in order to use the allocated resources (e.g., QoS) during the
> forwarding of packets belonging to a given detnet-flow. We have two options:
> (i) P nodes recognize "d-pw" label to identify the detnet-flow. This would mean that P nodes have to
> walk through the whole label stack. And I think also that "d-pw" label value must be globally unique

Depends on what you mean by "globally unique", it is the same end to
end, i.e. between A and B, but not unique in the sense that same the
label value cannot be used be A and Z signifying something totally
different.


> in the network to make life simple! That can be a scalability issue ...
> (ii) We are using different LSP per detnet-flow. This would make identification more simple for P nodes
> but raises scalability issues for the LSPs.
>
> 2, Distinguishing replica flows (required for OAM purposes)
> Let's assume that "node1 and node5" and "node2 and node6" are collapsed. I have created slide13
> based on your slide7 (collapsed nodes denoted as node15 and node26). As a result the upper and
> lower MS-PWs shares the first and second hop link when leaving nodeA. Node15 cannot distinguish
> the two replica flows only using the "d-pw" label. We should consider to use different "d-pw" label
> value per "detnet-flow segment". Such a scenario is shown on slide14. Using different "d-pw" labels
> may furthermore obsolete the PW-labels ...

Why does the nodes need to know the detnet label, isn't it enough that 
the QoS requirements are known?

This actually begs the question whether we need the intermediary PW at 
all, we could work with one or two RSVP_TE tunnels and the detnet pw
label.

/Loa
>
> Cheers
> Bala'zs
>
> -----Original Message-----
> From: Detnet-dp-dt [mailto:[e-mail]] On Behalf Of Loa Andersson
> Sent: Saturday, January 14, 2017 5:29 AM
> To: [e-mail]
> Subject: [Detnet-dp-dt] a quick look at the replication/discarding case for detnet flows
>
> Folks,
>
> I took a quick look at the replication / discarding case we talked about at the meeting this week.
>
> Please remember that so far this is not a proposal, just a demonstration that there is at least one way of doing it.
>
> What is there can bee revised, improved, changed or discarded if we find something better. Take a look a send comments.
>
> /loa
>
> Warning: I have a grave case of dyslexia, so any odd or inventive spelling is pure accident.
>
>
>
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-- 


Loa Andersson                        email: [e-mail]
Senior MPLS Expert                          [e-mail]
Huawei Technologies (consultant)     phone: [phone]