Subject: [arch-d] New I-D: Considerations on Internet Consolidation and the Internet Architecture

From: Dan York <[email-masked]>
Date: Wed, 24 Oct 2018 10:21:20 +0000

FYI, Jari Arkko published a new draft yesterday on behalf of several IAB members with the title "Considerations on Internet Consolidation and the Internet Architecture”:

https://tools.ietf.org/html/draft-arkko-iab-internet-consolidation-00

The text states that the draft is based off of the IAB blog post back in March 2018 - https://www.ietf.org/blog/consolidation/ - as well as a new post Jari and Brian Trammell have written for the APNIC and RIPE sites: https://blog.apnic.net/2018/10/24/opinion-consolidation-centralization-and-the-internet-architecture/

The abstract of the Internet Draft is:

   Many of us have held a vision of the Internet as the ultimate
   distributed platform that allows communication, the provision of
   services, and competition from any corner of the world.  But as the
   Internet has matured, it seems to also feed the creation of large,
   centralised entities in many areas.  This phenomenon could be looked
   at from many different angles, but this memo considers the topic from
   the perspective of how available technology and Internet architecture
   drives different market directions.

This list was pointed to as one place to discuss the draft:

   "Note: If you are interested on this or other architecture-related
   topics, please subscribe to the IAB architecture-discuss mailing list
   as one forum for discussion.”

The main content ends with a section 3, “Actions”, that lists these questions for discussion:

   Are there assumptions about the Internet architecture that no longer
   hold in a world where larger, more centralised entities provide big
   parts of the Internet service?  If the world changes, the Internet
   and its technology/architecture may have to match those changes.
   It appears that level the playing field for new entrants or small
   players brings potential benefits.  Are there technical solutions
   that are missing today?

   Assuming that one does not wish for regulation, technologies that
   support distributed architectures, open source implementations of
   currently centralised network functions, or help increase user's
   control can be beneficial.  Federation, for example, would help
   enable distributed services in situations where smaller entities
   would like to collaborate.

   Similarly, in an asymmetric power balance between users and services,
   tools that enable the user to control what information is provided to
   a particular service can be very helpful.  Some such tools exist, for
   instance, in the privacy and tracking-prevention modes of popular
   browsers but why are these modes not the default, and could we
   develop them further?

   It is also surprising that in the age of software-defined everything,
   we can program almost anything else except the globally provided,
   packaged services.  Opening up interfaces would allow the building of
   additional, innovative services, and better match with users' needs.

   Silver bullets are rare, of course.  Internet service markets
   sometimes fragment rather than cooperate through federation.  And the
   asymmetric power balances are easiest changed with data that is in
   your control, but it is much harder to change when someone else holds
   it.  Nevertheless, the exploration of solutions to ensure the
   Internet is kept open for new innovations and in the control of users
   is very important.

   What IETF topics that should be pursued to address some of the issues
   around consolidation?

   What measurements relating to the developments centralization or
   consolidation should be pursued?

   What research -- such as distributed Internet architectures -- should
   be driven forward?

They are all good questions. I do have some thoughts of my own on these questions, but I will send those in separate messages (or perhaps will write about them in an I-D or blog post).

Dan

--
Dan York
Director of Web Strategy, Internet Society
[email-masked]<mailto:[email-masked]>   +1-802-735-1624
Jabber: [email-masked]<mailto:[email-masked]>  Skype: danyork   http://twitter.com/danyork

http://www.internetsociety.org/

---

From: Bob Briscoe <[email-masked]>
Date: Wed, 24 Oct 2018 16:09:53 +0100

Jari and all,

Thx for writing this down.
[and Dan, thx for pointing this out]

1/ Another way to look at this is that the folks that designed the 
Internet did a good job of making it business-model-agnostic, cos it was 
generally designed to be highly distributed, but it's working well as 
distributed technology under a highly centralized business model.

2/ On the 'Permissionless Completeness Problem', at whatever stage in 
history you look at a value chain (aka stack of businesses built atop 
each other) the top ones are typically closed. That doesn't mean they 
always will be. A common progression in industrial organization where 
there's a natural monopoly at a particular layer (say L) is:

  * at layer L business make a land-grab for the largest market share by
    appearing to be open and free
  * then the winner closes off layer L to lock their size advantage in
  * they build new products on top (layer M), locked-in to the layer
    below (L)
  * in order to expand, the winner starts wholesaling their layer L
    product, so other M businesses can build and innovate in different
    ways on top, rather than the winner having to maintain a retail
    relationship with everyone (but the winner keeps its competitors
    dependent on its layer L)
  * so, L gradually becomes a commodity (sometimes aided by market
    regulation), and all the action moves to layer M
  * layer M could in turn become the platform for the next set of
    applications at layer N, and the process repeats

For instance, Microsoft became dominant in the PC market by repeating 
this process: its BIOS became the platform for DOS, then DOS the 
platform for Windows, then Windows the platform for Office, then Office 
became the platform for various forms of automation. And you can see how 
Microsoft has always opened up what used to be the highest layer as it 
tried to expand by wholesaling to allow others to create new markets 
faster than it could.

The same could happen with all the apps built over maps and location 
services.

Another example might be VR, which is starting as an app, but then it 
will probably just become a way to deliver new apps over a VR platform 
(e.g. virtual shopping, virtual theme parks, etc) and the VR platform 
itself will consolidate and commoditize.

3/ The important technical message is that it's much easier to start 
with an open platform so you can close it off and open it up again. 
Starting with closed technology is a dead-end.

4/ Finally, we have to remember that open innovation is only necessary 
to create new businesses and opportunities. You would expect there to be 
a more closed period when businesses milk their innovations. That's the 
stage when the businesses pull in the cash to allow them to invest in 
the next round of innovation.

5/ Of course, this is all a very optimistic view. What actually happens 
is that incumbents try to hold on to their gains for far too long, they 
use scurrilous tactics to undermine innovations by others, etc. etc. But 
that's all part of the rough and tumble, the rise and fall, of different 
businesses over decades and centuries. I'm just trying to give optimism 
over a (very) long run view.

Bob

On 24/10/2018 11:21, Dan York wrote:
> FYI, Jari Arkko published a new draft yesterday on behalf of several 
> IAB members with the title "Considerations on Internet Consolidation 
> and the Internet Architecture”:
>
> The text states that the draft is based off of the IAB blog post back 
> in March 2018 - https://www.ietf.org/blog/consolidation/ - as well as 
> a new post Jari and Brian Trammell have written for the APNIC and RIPE 
> sites: 
> https://blog.apnic.net/2018/10/24/opinion-consolidation-centralization-and-the-internet-architecture/
>
> They are all good questions. I do have some thoughts of my own on 
> these questions, but I will send those in separate messages (or 
> perhaps will write about them in an I-D or blog post).
>
> Dan
>
> --
> Dan York
> [email-masked] <mailto:[email-masked]> +1-802-735-1624
> Jabber: [email-masked] <mailto:[email-masked]> 
>  Skype: danyork http://twitter.com/danyork
>
> _______________________________________________
> Architecture-discuss mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/architecture-discuss

-- 
________________________________________________________________
Bob Briscoe                               http://bobbriscoe.net/

---

From: Stephen Farrell <[email-masked]>
Date: Wed, 24 Oct 2018 17:32:17 +0100

Hi Bob,

While I like what you wrote, I'm not sure I follow this bit..

> Starting with closed technology is a dead-end.

Again, I like the message but I'm not sure if one can justify
that or not - do you have examples of starting with a closed
technology forced it into a dead-end?

Ta,
S.

---

From: Spencer Dawkins at IETF <[email-masked]>
Date: Wed, 24 Oct 2018 14:15:02 -0500

Hi, Stephen,

> technology forced it into a dead-end?

I suspect that the people who can best answer this question are the least
likely to be subscribed to this mailing list, but I thought the canonical
examples for this in networking were the pre-IP computer networking
technologies like IBM's SNA. And they were closed enough that everyone had
their own -
https://en.wikipedia.org/wiki/IBM_Systems_Network_Architecture#Competitors
maps roughly on what I remember as an outsider. If you wanted
internetworking and weren't latched onto one of those manufacturers, you
were kind of forced into either using the Internet protocols or waiting for
the OSI protocols to appear.

Or both. I notice that Ross Callon's AD titles started out as OSI
Transition and moved to OSI Coexistence :-) ... .

I don't know whether Xerox XNS or AppleTalk would have qualified or not - I
just wasn't there for either of them, in a meaningful way.

Does that help?

Spencer

---

From: Jari Arkko <[email-masked]>
Date: Wed, 24 Oct 2018 19:42:59 +0000

Thanks Bob for this.

> 1/ Another way to look at this is that the folks that designed the Internet did a good job of making it business-model-agnostic, cos it was generally designed to be highly distributed, but it's working well as distributed technology under a highly centralized business model.

Yes.

> 2/ On the 'Permissionless Completeness Problem', at whatever stage in history you look at a value chain (aka stack of businesses built atop each other) the top ones are typically closed. That doesn't mean they always will be. A common progression in industrial organization where there's a natural monopoly at a particular layer (say L) is:
> at layer L business make a land-grab for the largest market share by appearing to be open and free 
> then the winner closes off layer L to lock their size advantage in
> they build new products on top (layer M), locked-in to the layer below (L)
> in order to expand, the winner starts wholesaling their layer L product, so other M businesses can build and innovate in different ways on top, rather than the winner having to maintain a retail relationship with everyone (but the winner keeps its competitors dependent on its layer L)
> so, L gradually becomes a commodity (sometimes aided by market regulation), and all the action moves to layer M
> layer M could in turn become the platform for the next set of applications at layer N, and the process repeats
> For instance, Microsoft became dominant in the PC market by repeating this process: its BIOS became the platform for DOS, then DOS the platform for Windows, then Windows the platform for Office, then Office became the platform for various forms of automation. And you can see how Microsoft has always opened up what used to be the highest layer as it tried to expand by wholesaling to allow others to create new markets faster than it could.
> 
> The same could happen with all the apps built over maps and location services.
> 
> Another example might be VR, which is starting as an app, but then it will probably just become a way to deliver new apps over a VR platform (e.g. virtual shopping, virtual theme parks, etc) and the VR platform itself will consolidate and commoditize.

Yes, we’ve seen this movie many times (although I wouldn’t necessarily exclude the existence of other movies as well).

> 3/ The important technical message is that it's much easier to start with an open platform so you can close it off and open it up again. Starting with closed technology is a dead-end.

Hmm. Not sure I entirely agree with you. I certainly think personally that open technology is better than closed. But I don’t think the world works like you say in all cases, there are plenty of examples where something proprietary got developed and it flourishes. Of course, in most cases that proprietary thing runs on top of more open things. Nice cars run on public roads, cool gadgets use Internet for transport, etc. And there’s nothing wrong with that, I believe in private enterprising and innovation. 

> 4/ Finally, we have to remember that open innovation is only necessary to create new businesses and opportunities. You would expect there to be a more closed period when businesses milk their innovations. That's the stage when the businesses pull in the cash to allow them to invest in the next round of innovation

Everything has its time; at some point whatever market there was for, I don’t know, say, horse-drawn carriages comes to an end and other things replace it. Sometimes there are clever companies that can ride the wave of new technology and move along to new things successfully, sometimes they die in the process. That’s all good of course as well.

> 5/ Of course, this is all a very optimistic view. What actually happens is that incumbents try to hold on to their gains for far too long, they use scurrilous tactics to undermine innovations by others, etc. etc. But that's all part of the rough and tumble, the rise and fall, of different businesses over decades and centuries. I'm just trying to give optimism over a (very) long run view.

I am also very optimistic :-)

You make a valid point of course that things will evolve and change. And sometimes entities on a market will either be forced out or will voluntarily move. And sometimes they make the market they leave more easily accessible, more open. And at other times they didn’t leave until the whole thing was no longer necessary :-)

But I don’t think this relieves us from the need to understand the world as it is today, to understand the tussles and power struggles and the role of technology in it, or to try to see if there are things we can improve.

Jari

---

From: "[email-masked]" <[email-masked]>
Date: Wed, 24 Oct 2018 22:23:38 +0000

Thanks for raising this important issue. Just to add an historical 
perspective:

The Internet was not the first new media that was going to create an 
utopian connected world. Tim Wu points this out very clearly in "The 
Master Switch" (2010) - which also clearly predicted this consolidation 
in the Internet space. From electricity and telephony on, and through 
radio and television, we can see new media which originally had quite 
different uses until the monopolisation took over. The telephone was "a 
universal wire system for the electrical transmission of intelligence"; 
radio was originally conceived as something more like ham radio 
communications than a consolidated broadcasting model: the movie camera 
did not foresee Hollywood: and television was going to be an interactive 
media as well.

So we should not be surprised at what has happened with the Internet and 
with the fact that this consolidated model is becoming the dominant 
model of internet usage, and to many people what it is all about. We can 
expect that narrowing to a few platforms to continue.

I mention this because, to answer Jari's question, I cannot see how 
tweaking standards in any of the previous media would have changed this 
phenomena. So I am not sure anything can be done in this area.

What probably is necessary is anti-trust measures - and I believe this 
is the theme of Wu's new book "The Curse of Bigness - Antitrust in the 
New Gilded Age) - there is a review at 
http://www.boundary2.org/2018/10/richard-hill-too-big-to-be-review-of-wu-the-curse-of-bigness-antitrust-in-the-new-gilded-age/).

I personally think the challenge is bigger than just economic domination 
- because how people think and what they think about political issues is 
to a largely degree determined by dominant media players. Elections can 
be determined by dominant media players, and, as Henry Kissinger points 
out in "How the Enlightenment Ends" (see 
https://www.theatlantic.com/magazine/archive/2018/06/henry-kissinger-ai-could-mean-the-end-of-human-history/559124/), 
the capacity of humans to think critically is also severely challenged 
by the way the Internet and associated technologies have evolved.

I just wanted to provide this background: because the problem is 
substantial, and much though I would welcome any technical development 
that helped to address this, I don't think there will be one.

Which doesn't mean there is no role for the technical community or for 
IAB.  All of us can help raise awareness of what is happening and the 
ramifications. Perhaps this draft - perhaps with some amendments - can 
serve a useful purpose in awareness raising of the substantial issues 
raised by media consolidation.

Ian Peter

---

From: Vittorio Bertola <[email-masked]>
Date: Thu, 25 Oct 2018 05:41:45 +0200 (CEST)

> Il 24 ottobre 2018 alle 12.21 Dan York <[email-masked]> ha scritto:
> 
Just a couple of days ago on the HRPC list I was saying that we should write a draft entitled "Centralization and consolidation are an attack", so it looks like the IAB read in our minds :-)

I find the draft right on spot and well thought out. It mentions all the situations that I find more troubling, from email to DNS-over-HTTPS going through social networks (I would have added a couple of lines on instant messaging as well, as it was the intermediate consolidation/walled-garden-construction step between email and social networks, and it's one of the best examples of how the lack of federation led to cumbersome user experiences).

I would perhaps add a consideration on another problem: the more the Internet's services get consolidated into the hands of a few companies, often concentrated in very few parts of the world, the more this creates tensions around cultural diversity (for example, in standards on which online content/behaviour is acceptable and how to deal with the unacceptable ones) and around national sovereignty, which promote negative reactions leaning towards fragmentation and the rejection of the permissionless innovation and multistakeholder management model.

As for the remediation, though in the end some situations (as we saw with the GDPR) may only be addressed by the dreaded last resort of regulation, I think that before releasing new protocols the IETF should pay more attention to their potential centralizing effects - perhaps a specific "centralization considerations" section could be added when appropriate.

One could also think whether the IETF should actually be proactive in promoting protocol development work aimed at "opening up" fields that otherwise will only evolve towards the usual set of walled gardens: for example, I am currently also working on online identity management (distributed and federated single sign-on, data flow and consent management etc) which, unless appropriate standards are created and promoted, is going to be the next instant-messaging-like mess of non-interoperable services - and identity is nowadays the fundamental layer for pretty much everything else.

It would be useful to understand what the next steps for this draft could be and how can one contribute effectively.

Regards, 

--

Vittorio Bertola | Head of Policy & Innovation, Open-Xchange
[email-masked] mailto:[email-masked] 
Office @ Via Treviso 12, 10144 Torino, Italy

---

From: William_J_G Overington <[email-masked]>
Date: Thu, 25 Oct 2018 10:15:54 +0100 (BST)

> Again, I like the message but I'm not sure if one can justify that or not - do you have examples of starting with a closed technology forced it into a dead-end?

An example is that where a business develops a software product that it considers will only need to use the languages of Western Europe and decides to use 8-bit character encoding because that is all that is needed. Unicode was readily available to use, but the business decided that 8-bit character codes was all that was needed.

Some time later, maybe several years later, a need is found to extend the languages available to be used with the product to include Polish and Czech.

As 8-bit character encoding cannot do that easily - yes, old fashioned code pages, but it gets problematic - the business has to decide whether the need for expansion is not to be followed up or whether a major rewriting of the software needs to be funded.

Had the business used Unicode in the first place, even though the software product at the time only needed to be used for the languages of Western Europe, then when the need for Polish and Czech arose, expansion would have been straightforward and Japanese and various Indian languages could be straightforwardly included too, as well as many other languages.

Also, embarrassment could be avoided when one of the customers asks for a version in Welsh, mentioning that the business was claiming that all the languages of Western Europe are supported.

Please consider the possibility of a business producing an app for a mobile device that implements the invention described in the following publication and publications linked from it.

http://www.users.globalnet.co.uk/~ngo/a_completed_publication_about_localizable_sentences_research.pdf

The link is safe, it is a personal webspace hosted by Plusnet PLC on their server.

If the business were to decide just to support English, French, German, Italian and Spanish to start and decided that an 8-bit character encoding were sufficient for its needs, then all might go well. Then support for Danish and Swedish might be added. All might still be going well. It would be when support for Japanese and Polish and Welsh were needed that the problems would start. Yet if the business starts with a Unicode encoding for the characters, then the later expansion would be straightforward. The same set of languages might still be used at the start, but the technological capacity to expand the set to any language that can be encoded using Unicode is there for use if needed later, even though not used at the start.

William Overington

Thursday 25 October 2018

---

From: Toerless Eckert <[email-masked]>
Date: Thu, 25 Oct 2018 16:49:08 +0200

To me this example is more around support for agile
extensibility/evolution as opposed to waterfall committee designs.

In the early nineties at least one router companies claim to fame in
certain circles was that when a problem was reported by a customer, they
would receive a fixed version of the router software within 24 hours and
would deploy them in 24 themselves. I think these days these two number
are the same, but the unit has changed from hours to weeks and the
probability for it to happen at all went from 90% to 30%.

So while the network industry is stuck in ossification and slowdown,
the principle was perfected in other industries to create a lot more
innovation and business growth e.g.: apps in DCs, devops, etc. pp.
In DCs, these principles are also applied to networking, but only as far
as it can be done with software that others than the infrastructure
owner can develop.

This is what the networking industry at large outside the DC needs to
get back to, but that would require more focus of the IETF on software
and systems architecture as opposed to only interoperability on wires
via protocols. See my prior email wrt. IETF and standards.

Cheers
    Toerless

-- 
---
[email-masked]

---

From: Jari Arkko <[email-masked]>
Date: Thu, 25 Oct 2018 14:52:39 +0000

Good point. I agree.

Jari

---

From: Niels ten Oever <[email-masked]>
Date: Fri, 26 Oct 2018 11:43:53 +0200

Hi all,

Thanks a lot for this document and the discussion. A lot of economic
drivers and examples are mentioned on the lists as well as in the draft,
such as for instance:

   Consolidation is driven by economic factors relating to scale and
   ability to reach a large market over the Internet.  In general, an
   efficient market such as the Internet tends to enable winners to take
   large market shares.

Whereas there are also theories around that claim that the distributed
architecture of the Internet would lead to a perfect market which would
guarantee competition. It would be great if the authors would engage a
bit more with economic theory (and or political economy literature). For
instance, there are also a lot of costs involved with centralization.
And why does email federate and social media don't?

While reading your draft I regularly asked myself: is this a
description, an explanation, or a conversation starter? I hope your
draft can be more clear about which parts describe the current state of
affairs, and which part explain it.

Some other text based notes:

The usage of powerful here is not quite clear to me. Does it mean
stable, versatile, or something else?

   Paradoxically, if the underlying network is sufficiently powerful,
   the applications on top can evolve without similar pressures for
   interoperability, leading to the closed but highly valuable services
   discussed above.  We call this the Permissionless Completeness
   Problem.

Here you discuss the network-effect of email services. To what extend is
this technical? And t what extend is this limited to email services?

   For instance, some technical issues have historically not been easy
   to solve, such as e-mail spam, which has lead to reliance on non-
   technical solutions.  Today, it is becoming increasingly difficult to
   run your own mail services, essentially forcing many organisations
   and individuals to employ larger providers.  The issues relate
   directly to size of entities; no one can afford to disconnect from
   the largest providers.  But as a small entity, there is little
   leverage to convince peer entities or various supporting white/
   blacklist entities to deal with you properly.

Here you describe that more data = better, whereas several pieces of
research have shown that it is not the amount of data, but the accuracy
and relevance of it. And these do not necessarily increase with more data.

   Many Internet services are based on gathering data about users, and
   using that data for, for instance, targeted advertisements.  More
   data from more users makes it possible to run a service more
   accurately or with better results; here again scale brings
   advantages.

Here a link to Geoff Huston's semial blog is probably in order
http://www.circleid.com/posts/20170311_the_internet_gilded_age/

   Another trend is that more and more content is becoming available
   locally, from a content delivery or provider function directly on
   your own ISP's network.  We predict that eventually most content will
   be delivered this way, reducing the role that global IP connections
   across the Internet play.  By some metrics this has already happened;
   what practical - positive or negative - impacts might this have on
   the Internet technology?

Here you argue that bigger entities can better a innovating and using
more recent technology, but is this really true? I thought smaller
organization could actually move faster.

   There are also security tradeoffs.  Large entities are generally
   better equipped to move to more recent and more secure technology.
   For instance, the Domain Name System (DNS) shows signs of ageing but
   due to the legacy of deployed systems, has changed very slowly.
   Newer technology developed at the IETF enables DNS queries to be
   performed confidentially, but its deployment is happening mostly in
   browsers that use global DNS resolver services, such as Cloudflare's
   1.1.1.1 or Google's 8.8.8.8.  This results in faster evolution and
   better security for end users.

Here you describe that the world changes, and that therefore the
Internet architecture should adapt. But the relation is also the other
way around! The architecture is facilitating oligopolies:

   If the world changes, the Internet
   and its technology/architecture may have to match those changes.

These were just some first thoughts, but am looking forward to following
the discussion and reading it again!

Best,

Niels

On 10/25/2018 05:41 AM, Vittorio Bertola wrote:
> Just a couple of days ago on the HRPC list I was saying that we should
> write a draft entitled "Centralization and consolidation are an attack",
> so it looks like the IAB read in our minds :-)
> 
> I find the draft right on spot and well thought out. It mentions all the
> situations that I find more troubling, from email to DNS-over-HTTPS
> going through social networks (I would have added a couple of lines on
> instant messaging as well, as it was the intermediate
> consolidation/walled-garden-construction step between email and social
> networks, and it's one of the best examples of how the lack of
> federation led to cumbersome user experiences).
> 
> I would perhaps add a consideration on another problem: the more the
> Internet's services get consolidated into the hands of a few companies,
> often concentrated in very few parts of the world, the more this creates
> tensions around cultural diversity (for example, in standards on which
> online content/behaviour is acceptable and how to deal with the
> unacceptable ones) and around national sovereignty, which promote
> negative reactions leaning towards fragmentation and the rejection of
> the permissionless innovation and multistakeholder management model.
> 
> As for the remediation, though in the end some situations (as we saw
> with the GDPR) may only be addressed by the dreaded last resort of
> regulation, I think that before releasing new protocols the IETF should
> pay more attention to their potential centralizing effects - perhaps a
> specific "centralization considerations" section could be added when
> appropriate.
> 
> One could also think whether the IETF should actually be proactive in
> promoting protocol development work aimed at "opening up" fields that
> otherwise will only evolve towards the usual set of walled gardens: for
> example, I am currently also working on online identity management
> (distributed and federated single sign-on, data flow and consent
> management etc) which, unless appropriate standards are created and
> promoted, is going to be the next instant-messaging-like mess of
> non-interoperable services - and identity is nowadays the fundamental
> layer for pretty much everything else.
> 
> It would be useful to understand what the next steps for this draft
> could be and how can one contribute effectively.
> 
> Regards, 
> 
> -- 
> 
> [email-masked] <mailto:[email-masked]> 

-- 
Niels ten Oever
Researcher and PhD Candidate
Datactive Research Group
University of Amsterdam

PGP fingerprint	   2458 0B70 5C4A FD8A 9488
                   643A 0ED8 3F3A 468A C8B3

---

From: Thomas Beaver <[email-masked]>
Date: Sun, 28 Oct 2018 16:35:04 -0400

Niels,

Just tossing in my 2c about one particular thing that you questioned.

   "The usage of powerful here is not quite clear to me. Does it mean
   stable, versatile, or something else?
   
      Problem."

I agree that it should be clarified. However, my interpretation of 
"powerful" in this paragraph is based loosely off the various metrics 
that have been covered in other protocols such as EIGRP. More 
specifically, "Bandwidth, Reliability, Load, and Delay". These metrics 
have been around for a long time but have rarely been used. New 
developments such as Segment Routing are attempting to give the 
applications more control over what it requires such as low latency or 
high bandwidth. Segment Routing deployed in an operators network with 
various link types will allow applications to take the best path for 
their use case scenario, in turn enhancing the customer experience. In 
this situation, Segment Routing would facilitate a "powerful" network. 
https://tools.ietf.org/html/rfc8402
Segment Routing (SR) leverages the source routing paradigm. A node 
steers a packet through an ordered list of instructions, called 
"segments". A segment can represent any instruction, topological or 
service based. A segment can have a semantic local to an SR node or 
global within an SR domain. SR provides a mechanism that allows a flow 
to be restricted to a specific topological path, while maintaining 
per-flow state only at the ingress node(s) to the SR domain. SR can be 
directly applied to the MPLS architecture with no change to the 
forwarding plane. A segment is encoded as an MPLS label. An ordered list 
of segments is encoded as a stack of labels. The segment to process is 
on the top of the stack. Upon completion of a segment, the related label 
is popped from the stack. SR can be applied to the IPv6 architecture, 
with a new type of routing header. A segment is encoded as an IPv6 
address. An ordered list of segments is encoded as an ordered list of 
IPv6 addresses in the routing header. The active segment is indicated by 
the Destination Address (DA) of the packet. The next active segment is 
indicated by a pointer in the new routing header.

Regards, Thomas Beaver

On 10/26/2018 5:43 AM, Niels ten Oever wrote:
> >> Il 24 ottobre 2018 alle 12.21 Dan York <york at isoc.org> ha scritto:
> >>
> > vittorio.bertola at open-xchange.com <mailto:vittorio.bertola  at open-xchange.com>
> > Architecture-discuss at ietf.org