Re: [Detnet-dp-dt] Using MS-PW concept for the d-pw

[Loa Andersson <[e-mail]>]

Yuanlong,

The L-laabel is ther to make the the intermediate not (S-PE) know what
to do whit the packet, the d-pw label was not allocated by the S-PE, so
it does not ahve any knowledge what it means.

If you let the S-PEs allocate and swap d-pw's, the next S-PE or a T-PE 
can't coordinate for the same packet coming in on from tow different
nodes.

But I feel like we are going in circles, can we agree on the corner 
stones first?

Do we want all possible/conceivable control mechanism be within scope?



/Loa


On 2017-02-25 15:18, Jiangyuanlong wrote:
> I agreed to alternative 2. L-label is not needed, S-PE must look into the PW label (further, extract sequence number in the CW) of a packet, and all FRER semantics can be coupled with the PW label.
>
> -----Original Message-----
> From: Jouni Korhonen [mailto:[e-mail]]
> Sent: Saturday, February 25, 2017 3:07 PM
> To: Jiangyuanlong
> Cc: [e-mail]; Loa Andersson
> Subject: Re: [Detnet-dp-dt] Using MS-PW concept for the d-pw
>
> Hi,
>
>> [YJ] I regard the L-Labels and T-labels are the same LSP layer. If we look into the full MPLS label stack of a packet in a PW, normally there is an LSP label at the top (unless PHP is enabled for the last hop).
>> Not sure what is the L-Label in your picture, is it different from LSP label?
>
> L-labels have been so far in the discussion between MS-PW PEs. T-labels are between any LSR. L-labels are not PHPed i.e., even if PHP is enable the L-Label stays and the label above it gets popped (that we have been referring as T-Labels). T- and L-labels are just a naming convention. IF you don’t have “between MS-PW PEs” semantic associated with the L-Label, it is the same as T-Label ;)
>
>
>
> case L-labels are present.. (alternative 1)
>
>                      PHP
>                    -------->
> +------------+                  +------------+
> |  T-labels  |                  |  L-label   |
> +------------+                  +------------+
> |  L-label   |                  | d-pw label |
> +------------+                  +------------+
> | d-pw label |                  |            |
> +------------+                  |  Payload   |
> |            |                  |            |
> |  Payload   |                  +------------+
> |            |
> +------------+
>
> case no L-labels.. (alternative 2.. and also alternative 3 if you think T- and L-labels are the same)
>
>                      PHP
>                    -------->
> +------------+                  +------------+
> |  T-labels  |                  | d-pw label |
> +------------+                  +------------+
> | d-pw label |                  |            |
> +------------+                  |  Payload   |
> |            |                  |            |
> |  Payload   |                  +------------+
> |            |
> +------------+
>
>
>
>
>
> - Jouni
>

-- 


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