[mpls] Re: New Version Notification for draft-li-mpls-mna-entropy-03.txt

[Loa Andersson <[e-mail]>]

Tony, et.al.,

not that is know now what it is worth, but I made a clearer version
of the figure.

/LoaI made a

Den 04/09/2024 kl. 02:28, skrev Tony Li:
>
> Hi Loa,
>
> Your diagram arrived here badly mangled.  I’ve changed to a fix width 
> font and taken the
> liberty of trying to repair it.  Apologies if I’ve only broken it further.
>
>> +-----------------------------------------+
>>                     |                                   |
>> +---+                                       |
>>            +------| D |                                       |
>>            | +---+                                       |
>>            |        |        |
>>          +---+ +---------------------------------------+ |
>>    +-----| B |      | |
>>    |     +---+ +-------------------------------------+ | |
>>    |       | |                                     | | |
>>    |       | +---+                                   | | |
>>    |       +------| E |                                   | | |
>>    | +---+                                   | | |
>>    | |                                     | | |
>>    | +-----------------------------------+ | | |
>> |                                                    | | | |
>>  +---+ +-------+
>>  | A | |   Z   |
>>  +---+ +-------+
>> |                                                    | | | |
>>    |  +-----------------------------------+ | | |
>>    | |                                     | | |
>>    | +---+                                   | | |
>>    |       +------| F |    | | |
>>    |       | +---+                                   | | |
>>    |       | |                                     | | |
>>    |     +---+  +-------------------------------------+ | |
>>    +-----|C  |      | |
>>          +---+ +---------------------------------------+ |
>>            | |                                         |
>>            | +---+                                       |
>>            +------| G |                                       |
>> +---+                                       |
>> |                                         |
>> +-----------------------------------------+
>>
>>
>> Not a network model, but a description of load-sharing option. You 
>> say that
>> we need the number of paths that a packet may take through the 
>> network. In the figure above a packet coming into node from the can 
>> be sent either "north" or "south". If it sent "north" it will enter 
>> node B and again go north or south. Once a packet reach node D, E, F, 
>> or G, it traverses a part of the network that does not do 
>> load-sharing. (Yes, I'm lazy!) To me the load-sharing decision seem 
>> to a local matter, what is the impact of the fact that there are 8 
>> routes through the network? What seem to have a bigger impact is the 
>> number of out going load-sharing interface, but again that is local.
>
> I’m assuming here that the traffic flows from A to Z.
>
> Yes, load sharing is a completely local decision.  The goal is for 
> each system that has multiple paths to select an appropriate next hop,
> consistent with the overall path and avoiding packet reordering within 
> a flow. Since intermediate nodes do not have a clear understanding
> of the flows within an LSP, the Entropy Label/Value gives a hint to 
> downstream nodes about how to forward particular flows. If done
> correctly, packets with the same Entropy Label/Value will follow the 
> same path and thus avoid reordering.
>
>
> Tony
>
>

-- 
Loa Andersson
Senior MPLS Expert
Bronze Dragon Consulting
[e-mail]
[e-mail]