Re: [Lsr] LSR: Using DSCP for path/topology selection Q

[Jeff Tantsura <[e-mail]>]

Robert,

match DSCP X
set context Y or plane Z doesn’t make it any different.
It has been used and abused in any possible way. If you want to write a BCP
saying - use it for X/Y/Z but not for A/B/C because of.... - your business.

As to using it someplace else - I’d expect respective documents to cover
the use, flex-algo drafts as to your example.

More fundamentally, (flex-algo is the best example) we have got context
aware metadata in a form of: MPLS labels (SR SID), v6 EHs, plethora of
overlay encaps, etc, with accompanying CP extensions that can be used to
achieve exactly that.

Now tell me - why again DSCP?

P.S. in my previous life, working on 5G transport slicing (yes, i know :))
- i needed per slice identity over the common transport, we ended up
looking at UDP port ranges, rather than DSCP - too few bits

Cheers,
Jeff
On Thu, Nov 15, 2018 at 23:37 Robert Raszuk <[e-mail]> wrote:

> Jeff,
>
> > What architecture?
> > PBR is a form of:
> > match DSCP X
> > set next-hop Y
> > needs no interoperability...
>
> That's pretty narrow view. I could say the worst possible example :)  You
> would have to either encapsulate or apply your sample config consistently
> on every hop. Brrrrr.
>
> To me DSCP can be used to map packets to different routing context,
> different plane or can be used as a parameter in flex-algorithm.
>
> Thx,
> R.
>
>
>
>
>
> On Fri, Nov 16, 2018 at 8:19 AM Jeff Tantsura <[e-mail]>
> wrote:
>
>> Tony,
>>
>> What architecture?
>> PBR is a form of:
>> match DSCP X
>> set next-hop Y
>> needs no interoperability...
>> If someone wants to describe how they use a particular vendor feature to
>> solve a particular problem in a BCP, sure, the more BCPs - the better.
>>
>> Wrt using DSCP in routing decision process - it was a bad idea back then,
>> hasn’t got any better now... besides - now we have got a toolbox that
>> wasn’t available then.
>>
>> Cheers,
>> Jeff
>> On Thu, Nov 15, 2018 at 22:56 Tony Li <[e-mail]> wrote:
>>
>>>
>>>
>>> On Nov 15, 2018, at 8:47 PM, Jeff Tantsura <[e-mail]>
>>> wrote:
>>>
>>> The question is really - what is here to standardize?
>>>
>>>
>>>
>>> There’s a fine architectural BCP here: this is how we are solving
>>> problem XYZ.  Please don’t break this.
>>>
>>> Tony
>>>
>>>