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

[Jiangyuanlong <[e-mail]>]

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