Re: [Detnet-dp-dt] New update of the draft available

Okay.. seems we are in sync regarding what we want. We just talk past each other terminology and label concept wise. I’ll try to fix this into the draft.

- Jouni

-- 
Jouni Korhonen, Broadcom, Core Switching Group
+1-408-391-7160

> On Mar 12, 2017, at 11:03 PM, Loa Andersson <loa@pi.nu> wrote:
> 
> Jouni,
> 
> I'm sorry if I caused the confusion. A PW needs the PSN Tunnel, we have
> called L-Label because we use it for overlay also.
> 
> On 2017-03-13 07:44, Jouni Korhonen wrote:
>> I think there’s still a bit of confusion what constitutes T and L labels. Say I have a topology below:
>> 
>> 
>>          DA-T-PE     P       P       Php      DA-S-PE       Php    DA-T-PE
>> PW label     200      200     200     200    200 swp 300     300    300
>> L label
>> T label          123  swp 124 swp 125 pop                131 pop
> 
> Yes - but you don't need the T-label (it is optional), and only tunnel part of the way between two DA-*-PEs.
> 
> I think this is the case
>                       php                     php
>        DA-T-PE  P      P     DA-S-PE    P      P    DA-T-PE
> PW label    20   20    20    20 swp 30  30     30    terminate
> L label     13   14    php     push 40  50     php
> T label          <optional>
> 
> If you want we can talk about it, if you are online now.
> 
> /Loa
> 
>> 
>> Why would I need L-labels in the above case?
>> 
>>          DA-T-PE     P       P       Php      DA-S-PE       Php    DA-T-PE
>> PW label     200      200     200     200         200        200    200
>> L label      300      300     300     300    300 swp 400     400    400
>> T label          123  swp 124 swp 125 pop                131 pop
>> 
>> Here I could use the L-label to bypass DA-S-PE.
>> 
>> Correct me if this is not correct assumption..
>> 
>> 
>> - Jouni
>> 
>> 
>> 
>> 
>>> On Mar 10, 2017, at 6:38 PM, Loa Andersson <loa@pi.nu> wrote:
>>> 
>>> Jouni,
>>> 
>>> Mostly looks very good, the thing I don't understand is why you still say that the L-label is optional, it really isn't.
>>> 
>>> - we need it to deliver the d-pw label unchanged
>>> - since we can't guarantee that the "P" nodes are not able to do
>>> DetNet NSP, we can't set up the d-pw label with signaling that
>>> exposes the "request for DetNet NSP/FRER" to P nodes.
>>> - needed for protection
>>> - the end-to-end tunnel must be the innermost tunnel, carrying
>>> pw label
>>> 
>>> There is one case, if two DA-*-PEs are immediately adjacent, there the
>>> L-lable will be an implicit NULL label and not appear in the stack, but
>>> for the control plane it is there.
>>> 
>>> /Loa
>>> 
>>> On 2017-03-11 07:25, Jouni Korhonen wrote:
>>>> * Added Loa’s comments on the L-label.
>>>> * Added Janos’ comments.
>>>> * Added extended forwarder text.
>>>> * Added (speculative text.. can be removed) D bit to flow-id word so that we can check in a ring case the direction of the flow (note this does not double history buffer space as claimed.. did not bother to fix that)
>>>> * reworked the PW encapsulation pictures.
>>>> * Added more content to DA-*-PE descriptions.
>>>> 
>>>> - Jouni
>>>> 
>>>> 
>>> 
>>> --
>>> 
>>> 
>>> Loa Andersson                        email: loa@mail01.huawei.com
>>> Senior MPLS Expert                          loa@pi.nu
>>> Huawei Technologies (consultant)     phone: +46 739 81 21 64
>>> 
>>> _______________________________________________
>>> Detnet-dp-dt mailing list
>>> Detnet-dp-dt@ietf.org
>>> https://www.ietf.org/mailman/listinfo/detnet-dp-dt
>> 
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> 
> -- 
> 
> 
> Loa Andersson                        email: loa@mail01.huawei.com
> Senior MPLS Expert                          loa@pi.nu
> Huawei Technologies (consultant)     phone: +46 739 81 21 64