Shraddha,
On 17/08/2021 20:04, Shraddha Hegde wrote:
Peter,
no, I don't want to use affinities to do that. That's the whole point.
ASLA gives you per link per application signaling. No need to use affinities.
The usecase you are describing to exclude links from an application topology is
very straight
forward and how this is done is defined by applications.
TE applications have defined a topology filter data model that uses
link-affinities to Include/exclude links from topology
https://datatracker.ietf.org/doc/html/draft-bestbar-teas-yang-topology-filter-00.
In your example if application B is any TE application it would be natural to
use link-affinities.
If application B is LFA, RFC 7916 defines link-coloring and include exclude
policies to be used (Refer sec 6.2.3).
so it cannot use application bits on metric to exclude links.
If we assume application A and B are both Flex-algos, ASLA
flex-algo is a single application, so A and B does not make sense.
You can define flex-algo X and flex-algo Y and use different FAD to
exclude/include links as needed, using single set of affinities that are
advertised for flex-algo application as such.
I still do not see a problem
thanks,
Peter
natively doesn't support Per flex-algo attribute advertisement
and it is extremely complex to define user-defined bit masks for Each
flex-algo and assign the bit masks on the metric on every router.
Operator could use link-affinities to Exclude links
from flex-algo topology which is much simpler.
Rgds
Shraddha
Juniper Business Use Only
-----Original Message-----
From: Peter Psenak <[email protected]>
Sent: Saturday, July 31, 2021 1:07 AM
To: Shraddha Hegde <[email protected]>; Robert Raszuk <[email protected]>; Van De
Velde, Gunter (Nokia - BE/Antwerp) <[email protected]>
Cc: Les Ginsberg (ginsberg) <[email protected]>; Tony Li <[email protected]>;
[email protected]
Subject: Re: [Lsr] Generic metric: application-specific vs
application-independent
[External Email. Be cautious of content]
Shraddha,
On 30/07/2021 18:45, Shraddha Hegde wrote:
Peter,
imagine you have an application A and B and a link X. You advertise application
independent metric M on that link X >because you want application A to use it.
Application B is also enabled to use the metric M, but you do not want application B
to use metric M on the link X >(because you do not want application B to include
the link X in its topology). How do you do that without ASLA? The >answer is you
can't.
This is very straight forward to do without ASLA.
I would define an admin-group and assign that admin group on link X and
exclude that admin-group from Application B.
This is much common way how
operators exclude links from the topology.
no, I don't want to use affinities to do that. That's the whole point.
ASLA gives you per link per application signaling. No need to use affinities.
The alternative being proposed with ASLA is much more fragile.
An operator would have to set the bits for application A and Application B
for metric M on every link that he wants to include and reset the
application bit B on links that he wants to exclude for application B.
sorry, but setting affinities is not any easier, so the above argument is not
valid.
Peter
Imagine what would happen if he missed setting the bit or resetting
the bit on some of the links and how difficult it would be to debug.
Rgds
Shraddha
Juniper Business Use Only
-----Original Message-----
From: Peter Psenak <[email protected]>
Sent: Friday, July 30, 2021 7:09 PM
To: Shraddha Hegde <[email protected]>; Robert Raszuk
<[email protected]>; Van De Velde, Gunter (Nokia - BE/Antwerp)
<[email protected]>
Cc: Les Ginsberg (ginsberg) <[email protected]>; Tony Li
<[email protected]>; [email protected]
Subject: Re: [Lsr] Generic metric: application-specific vs
application-independent
[External Email. Be cautious of content]
Shraddha,
On 30/07/2021 15:22, Shraddha Hegde wrote:
Robert,
> Can anyone explain how do I map generic metric to selected
network applications I am to run in the network ?
Which application uses which metric type is defined by the application.
imagine you have an application A and B and a link X. You advertise application
independent metric M on that link X because you want application A to use it.
Application B is also enabled to use the metric M, but you do not want
application B to use metric M on the link X (because you do not want
application B to include the link X in its topology). How do you do that
without ASLA? The answer is you can't.
thanks,
Peter
For example in flex-algo FAD defines which metric-type its going to use.
In SR-TE, the constraint list specifies which metric-type it is going
to use.
Rgds
Shraddha
Juniper Business Use Only
*From:* Robert Raszuk <[email protected]>
*Sent:* Friday, July 30, 2021 6:20 PM
*To:* Van De Velde, Gunter (Nokia - BE/Antwerp)
<[email protected]>
*Cc:* Peter Psenak <[email protected]>; Shraddha Hegde
<[email protected]>; Les Ginsberg (ginsberg) <[email protected]>;
Tony Li <[email protected]>; [email protected]
*Subject:* Re: [Lsr] Generic metric: application-specific vs
application-independent
*[External Email. Be cautious of content]*
Hey Gunter,
> It doesn’t make sense to have Application specific values if a
particular metric is obtained only dynamically,
It sure does.
Please notice what ASLA RFCs say up front in the abstract. ASLA is
useful for:
A) application- specific values for a given attribute
AND
B) indication of which applications are using the advertised value
for a given link.
It does not matter if the value is same or different ... what matters
is automated and consistent indication which of my applications given
new metric applies to.
I already mentioned this to Ron here:
https://urldefense.com/v3/__https://mailarchive.ietf.org/arch/msg/lsr
/
OgGLI8yezUDWU-EZePoIj6y6ENk/__;!!NEt6yMaO-gk!VVLJCpIMrWixS17PeaBbfOpe
b NPO4JUW4jparIn36jHmhv4_-W2_q_Smwo7oIYgk$
<https://urldefense.com/v3/__https:/mailarchive.ietf.org/arch/msg/lsr
/
OgGLI8yezUDWU-EZePoIj6y6ENk/__;!!NEt6yMaO-gk!Tny8sU7cmjqLAbDVnliN7lck
7 J4tCBAHr10i3CW2G9oviUWo8b2RTJxCXc0gvWOz$>
Can anyone explain how do I map generic metric to selected network
applications I am to run in the network ?
Thx,
Robert.
On Fri, Jul 30, 2021 at 11:05 AM Van De Velde, Gunter (Nokia -
BE/Antwerp) <[email protected]
<mailto:[email protected]>> wrote:
A little late in the discussion... (PTO events do happen)
a quick opinion on the below discussion on whether Generic metric
sub-tlv should be encoded on a ASLA or not.
For me, it depends on how the metric for the corresponding
metric-type is obtained and if it can be configured (static).
It doesn’t make sense to have Application specific values if a
particular metric is obtained only dynamically, for eg, dynamically
measured delay is going to be same for all applications.
On the contrary, te-metric can be configured, and we can in
principle configure different values for different applications.
My opinion is that if any of the metric-types in the Generic metric
sub-tlv can be configured, it should be inside the ASLA.
G/
_______________________________________________
Lsr mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/lsr
