Re: [Bier] BIER: draft-eckert-bier-cgm2-rbs-01 with performance analysis simulation

["Xubing (Robin)" <[e-mail]>]

Dear Toerless,

Please find my answer as follow:

> Robin, two Q:
>1. The new text mentions "in our graphs", but the text does not include any such graphs (yet).
>I guess such a graph would be even worse to convert to ASCII than the topology.
>Maybe post whatever format you have those results in to github (PDF, png...) and then we actually may want to see if/how a PDF version of the draft could include better than just ASCII art. Certainly a good reason to finally try it out.
>And short term we can just add references to such visuals to the draft.

Xubing: The graph has been uploaded to github with PNG type. It is hard to convert it to ASCII art. (https://github.com/toerless/bier-cgm2-rbs)


>2; Is it correct to assume that the hops through the topology that you simulated are "just" shortest-path, maybe with some ECMP choice - aka: the same paths that also BIER would choose given some "default" IGP routing setup ?

Xubing: Actually, the path of CGM2 is determined by the controller/algorithm, not depend on IGP or BGP protocol. And in the multiple paths scenario, CGM2 can choose the path hop-by-hop, and the shortest-path is 'just' one of the choices..



Best Regards

Bing Xu
Network Laboratory, 2012Labs, Huawei Technologies Co.,Ltd.
Tel : [phone] / Email : [e-mail]

This e-mail and its attachments contain confidential information from HUAWEI, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it!

-----Original Message-----
From: [e-mail] <[e-mail]>
Sent: Thursday, February 10, 2022 3:19 AM
To: [e-mail]
Cc: Xubing (Robin) <[e-mail]>
Subject: BIER: draft-eckert-bier-cgm2-rbs-01 with performance analysis simulation

Dear BIER-TE WG:

Robin did add a section (6.3) describing an initial performance gain analysis of CGM2/RBS to the github source (https://github.com/toerless/bier-cgm2-rbs), and i just did a bit of editorial fixup and posted it as -01 of the draft.

This actually is the first time i actually like the HTML'ized version of a draft, because the topology picture is so large it doesn't fit a single page:

https://www.ietf.org/archive/id/draft-eckert-bier-cgm2-rbs-01.html

The interesting piece about the comparison is that it is actually comparing CGM2/RBS to BIER, and not BIER-TE. Because BIER itself should be requiring less copies than BIER-TE, so the gain of CGM2/RBS over BIER-TE should be even higher, but the fact alone that you get away with fewer packet copies to large receiver sets even though the bitstring also needs to encode the path/tree towards the receivers is really cool.

Robin, two Q:

1. The new text mentions "in our graphs", but the text does not include any such graphs (yet).
I guess such a graph would be even worse to convert to ASCII than the topology.
Maybe post whatever format you have those results in to github (PDF, png...) and then we actually may want to see if/how a PDF version of the draft could include better than just ASCII art. Certainly a good reason to finally try it out.
And short term we can just add references to such visuals to the draft.

2; Is it correct to assume that the hops through the topology that you simulated are "just" shortest-path, maybe with some ECMP choice - aka: the same paths that also BIER would choose given some "default" IGP routing setup ?

Cheers
    Toerless