Re: [bess] Thought about "Application Routing" in draft-dunbar-bess-bgp-sdwan-usage

[Adrian Farrel <[e-mail]>]

Hi Linda,

 

Thank you so much for continuing to try to accommodate me. Please consider this my last attempt to fix this unless someone else on the mailing list joins in to support my opinion.

 

I do not believe the term “application forwarding” is either defined in the document or particularly meaningful. It is no better than “application routing” in this respect.

 

I think that you are trying to refer to “individual traffic flows associated with a specific application” (although you may intend to refer to “individual packets”). And you are either trying to describe how traffic is “classified” onto paths/tunnels (as in bullet 3) or trying to indicate how packets may be handled within the network (possibly bullet 4), or both.

 

You also have the use of an application identifier as a mechanism to classify traffic. If you go down that path you must discuss privacy and netneutrality even if all you have to say is that this function takes place within a private (enterprise) network where all users are assumed to be required to comply with the network operator’s usage rules.

 

I’ll stop now.

 

Once again, thanks for trying to make me happy 😊

 

Best,

Adrian

 

From: Linda Dunbar <[e-mail]> 
Sent: 30 July 2020 23:34
To: Najem, Basil <[e-mail]>; [e-mail]; [e-mail]
Cc: [e-mail]
Subject: RE: Thought about "Application Routing" in draft-dunbar-bess-bgp-sdwan-usage

 

Adrian, 

 

Thank you very much for the comments and suggestions. 

Per your suggestions, we have changed the wording to the following. Do you think it is clear? 

 

Here are some key characteristics of “SDWAN” networks:

-   Augment of transport, which refers to utilizing overlay paths over different underlay networks. Very often there are multiple parallel overlay paths between any two SDWAN edges, some of which are private networks over which traffic can traverse with or without encryption, others require encryption, e.g. over untrusted public networks. 

-   Enable direct Internet access from remote sites, instead hauling all traffic to Corporate HQ for centralized policy control. 

-   Some traffic can be forwarded based on their application IDs instead of based on destination IP addresses. For example, placing traffic onto specific overlay paths based on their application IDs.  

-   The Application forwarding can also be based on specific performance criteria (e.g. packets delay, packet loos, jitter) to provide better application performance by choosing the right underlay that meets or exceeds the specified criteria. 

 

If it is not clear, can you help to wordsmith it? 

 

Linda Dunbar

From: Najem, Basil <[e-mail] <mailto:[e-mail]> > 
Sent: Tuesday, July 28, 2020 9:46 AM
To: [e-mail] <mailto:[e-mail]> ; Linda Dunbar <[e-mail] <mailto:[e-mail]> >; [e-mail] <mailto:[e-mail]> 
Cc: [e-mail] <mailto:[e-mail]> 
Subject: RE: Thought about "Application Routing" in draft-dunbar-bess-bgp-sdwan-usage

 

Hi Adrian;

 

Given the context in the document, I’d revert back to the original paragraph (my proposed text in the thread) and change “route/routed” to “forward/forwarded”.

 

Regards;

 

Basil

 

From: Adrian Farrel <[e-mail] <mailto:[e-mail]> > 
Sent: July-28-20 10:07 AM
To: Najem, Basil <[e-mail] <mailto:[e-mail]> >; 'Linda Dunbar' <[e-mail] <mailto:[e-mail]> >; [e-mail] <mailto:[e-mail]> 
Cc: [e-mail] <mailto:[e-mail]> 
Subject: [EXT]RE: Thought about "Application Routing" in draft-dunbar-bess-bgp-sdwan-usage

 

The issue I am trying to get at is that the text you have in the draft is unclear and probably going to explode.

*	We have an approximate solution for that

 

The secondary issue is whether you are talking about routing/forwarding within the network, or placing the traffic onto tunnels at the edge.

*	You are pretty clear on what you mean, and I am fine with that since it fits with my understanding of VPN.
*	Possibly Linda is thinking about how those tunnels are maintained and operated to meet the service levels that they offer. That would be (I think) out of scope for a BGP VPN

 

Maybe we can polish the paragraph in question to become…

 

Better user experience can be provided by placing traffic flows for an application onto tunnels over an underlay network that meet or exceed the specified performance criteria (e.g., packets delay, packet lose, jitter) for those traffic flows.

 

Cheers,

Adrian

 

From: Najem, Basil <[e-mail] <mailto:[e-mail]> > 
Sent: 28 July 2020 14:28
To: [e-mail] <mailto:[e-mail]> ; 'Linda Dunbar' <[e-mail] <mailto:[e-mail]> >; [e-mail] <mailto:[e-mail]> 
Cc: [e-mail] <mailto:[e-mail]> 
Subject: RE: Thought about "Application Routing" in draft-dunbar-bess-bgp-sdwan-usage

 

Let’s get back to what SD-WAN is doing: it can steer/forward the application traffic based on specified performance criteria value requirement. This criteria is set by the subscriber (user) to ensure a better experience (by choosing the best tunnel over an underlay). Not sure what’s the issue here Adrian? Can we capture this statement as per your suggestion and remove the word “route” (or routed) and replace it with “forward” (or forwarded)? 

 

Regards;

 

Basil

 

 

From: Adrian Farrel <[e-mail] <mailto:[e-mail]> > 
Sent: July-28-20 9:19 AM
To: 'Linda Dunbar' <[e-mail] <mailto:[e-mail]> >; Najem, Basil <[e-mail] <mailto:[e-mail]> >; [e-mail] <mailto:[e-mail]> 
Cc: [e-mail] <mailto:[e-mail]> 
Subject: [EXT]RE: Thought about "Application Routing" in draft-dunbar-bess-bgp-sdwan-usage

 

Thanks to both Linda and Basil,

 

My response is a little unthought as I am currently following two simultaneous sessions (sorry about that), but it seems to me that the answers from the two of you seem to be slightly at odds.

 

Basil is talking about steering whole traffic flows onto tunnels to be carried over the network; Linda is talking about routing individual packets within the network.

 

I would still caution you to avoid tying too tightly to the term “application”. A single application may generate multiple flows with different performance criteria and you will treat the flows differently. Conversely, two applications may generate flows that have identical performance criteria.

 

Thanks,

Adrian

 

From: Linda Dunbar <[e-mail] <mailto:[e-mail]> > 
Sent: 28 July 2020 14:05
To: Najem, Basil <[e-mail] <mailto:[e-mail]> >; [e-mail] <mailto:[e-mail]> ; [e-mail] <mailto:[e-mail]> 
Cc: [e-mail] <mailto:[e-mail]> 
Subject: RE: Thought about "Application Routing" in draft-dunbar-bess-bgp-sdwan-usage

 

Adrian, 

 

You said: 

As will be seen from the Application Aware Networking (APN) effort, the concept of traffic flows being routed according to the identity of the application is made complicated by various privacy and security concerns, not to mention issues of registering application identities.

 

The "Application" doesn't necessary mean all the bits in the payload. The "Application" can be any criteria that Client has indicated to Network Operators, for example the IPsec SA header bits, the TCP/UDP port number, the Source Addresses, etc. 

The network will not alter the forwarding behavior unless there is the request from the client to inform the network to forward their traffic based on its provided criteria.

 

This draft, which was written 2 years ago, is indeed to show that BGP can be effectively used to “do something similar to APN: that is, to classify the service that a particular application-sourced flow wants to receive from the network”. 

 

Since SDWAN is over different types of underlay networks, with different performance and security aspects, clients may want their specific traffic to traverse specific underlay networks, or specific peers. 

 

Yes, indeed that the goal is to “ the packets are 'coloured' for routing and treatment in the network.”

 

There is another draft in IDR to describe the encoding “Color” or “IPsec SA ID”: https://datatracker.ietf.org/doc/draft-dunbar-idr-sdwan-edge-discovery/ <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdatatracker.ietf.org%2Fdoc%2Fdraft-dunbar-idr-sdwan-edge-discovery%2F&data=02%7C01%7Clinda.dunbar%40futurewei.com%7C44850878a9dc4196eccf08d83304e94c%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637315443483105481&sdata=noR0DNtSG7kVGTzqR98UCO33pMVQLFTvyOfCo1Jf%2BAk%3D&reserved=0> 

 

Welcome your comments to that draft. 

 

I will attend the APN side meeting on Thurs to understand more. 

 

 

Linda Dunbar

 

-----Original Message-----
From: Najem, Basil <[e-mail] <mailto:[e-mail]> > 
Sent: Tuesday, July 28, 2020 7:10 AM
To: [e-mail] <mailto:[e-mail]> ; [e-mail] <mailto:[e-mail]> 
Cc: [e-mail] <mailto:[e-mail]> 
Subject: RE: Thought about "Application Routing" in draft-dunbar-bess-bgp-sdwan-usage

 

Thanks Adrian for your comment.

 

How about changing the paragraph to something like:

 

"The application can be routed based on specific performance criteria (e.g. packets delay, packet lose, jitter) to provide a better experience by choosing a tunnel over an underlay that meets or exceeds the specified performance criteria threshold for that application"

 

Regards;

 

Basil

 

 

 

-----Original Message-----

From: Adrian Farrel <[e-mail] <mailto:[e-mail]> > 

Sent: July-28-20 8:01 AM

To: [e-mail] <mailto:[e-mail]> 

Cc: [e-mail] <mailto:[e-mail]> 

Subject: [EXT]Thought about "Application Routing" in draft-dunbar-bess-bgp-sdwan-usage

 

Hi,

 

As Linda noted in her agenda slot today, draft-dunbar-bess-bgp-sdwan-usage version 08 introduced a new paragraph in the Introduction that says:

 

    - The Application Routing can also be based on specific

       performance criteria (e.g. packets delay, packet loos, jitter)

       to provide better application performance by choosing the right

       underlay that meets or exceeds the specified criteria.

 

Firstly, s/loos/loss/ 😊

 

But I am concerned by the concept of "application routing" and I note that the term is not used elsewhere in the document nor is the concept expanded upon.

 

As will be seen from the Application Aware Networking (APN) effort, the concept of traffic flows being routed according to the identity of the application is made complicated by various privacy and security concerns, not to mention issues of registering application identities.

 

Fortunately, I suspect that this draft wants to do something similar to APN: that is, to classify the service that a particular application-sourced flow wants to receive from the network. This may be considerably more complex than DSCP, but the concept is the same that either a tunnel/pipe/flow is negotiated and established for use by the application, or the packets are 'coloured' for routing and treatment in the network.

 

I would suggest two things:

1. Be a lot more clear about what is meant by "application routing" possibly even using a different term 2. Have a look at the APN work - side meeting on Thursday; see https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2FAPN-Community%2FIETF108-Side-Meeting-APN <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2FAPN-Community%2FIETF108-Side-Meeting-APN&data=02%7C01%7Clinda.dunbar%40futurewei.com%7C44850878a9dc4196eccf08d83304e94c%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637315443483115477&sdata=1SI6sXCb0WQGtpvgQxFheQ1KhnOIZhnSDSpbmUA5mvY%3D&reserved=0> &amp;data=02%7C01%7Clinda.dunbar%40futurewei.com%7C456da5e6ae9e4fc3ff6808d832ef2ef0%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637315350161504633&amp;sdata=B4QkVHS%2FkUs%2BWFZgAFQ64BDIhNlIqYxnSrlQNOx%2Bblg%3D&amp;reserved=0 for all the details

 

Best,

Adrian

 

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