Network Coding for Content-Centric Networking / Named Data Networking: Considerations and Challenges
draft-irtf-nwcrg-nwc-ccn-reqs-09

(Via drafts-eval@iana.org): IESG/Authors/ISE:

The IANA Functions Operator has reviewed draft-irtf-nwcrg-nwc-ccn-reqs-09 and has the following comments:

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While it's often helpful for a document's IANA Considerations section to remain in place upon publication even if there are no actions, if the authors strongly prefer to remove it, we do not object.

If this assessment is not accurate, please respond as soon as possible.

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Amanda Baber
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[Ballot comment]
I do have some questions for the authors to consider, but nothing blocking that I can see. Thanks for the opportunity to review this document.

This is the kind of silly question one wonders about, but the top of the first page says

Network Coding Research Group

But the abstract says

Abstract

  This document is
  the product of the Coding for Efficient Network Communications
  Research Group (NWCRG) and the Information-Centric Networking
  Research Group (ICNRG).

My understanding is that the Abstract is correct. Perhaps both research groups could be named at the top of the first page? In my limited experience, that’s a free-form field.

In section 3, could you expand CS on first use?

This text

  In the case of non-
  coherent NC, that often comprises the use of Random Linear Coding
  (RLC), it is not necessary to know the network topology nor the
  intermediate coding operations [33].

Didn’t parse well for me. Perhaps

  In the case of non-
  coherent NC, which often uses Random Linear Coding
  (RLC), it is not necessary to know the network topology nor the
  intermediate coding operations [33].

I agree with Mirja’s first comment, that if there’s a reason why ICN is special and either benefits from NC differently or needs to be handled differently, explaining that would be great. I think Section 5 is getting at that, but maybe a forward pointer earlier in the document would be helpful.

In addition, I’m looking at

  NC combines multiple packets together with parts of the same content,
  and may do this at the source or at other nodes in the network.
  Network coded packets are not associated with a specific server, as
  they may have been combined within the network.  As NC is focused on
  what information should be encoded in a network packet instead of the
  specific host at which it has been generated, it is in line with the
  architecture of the CCNx/NDN core networking layer.

And wondering if NC could happen at a source OR in other nodes in the network, what would happen if it happened at a source AND in other nodes in the network. Whether both would be OK, or not, it’s probably worth saying something about that.

In Section 6.1,

  Naming content objects is as important for CCNx/NDN as naming hosts
  is in the current-day Internet [24].  In this section, two possible
  naming schemes are presented.

I wasn’t sure which naming schemes are being presented (do they have names? References? Or are they being described in this document for the first time?) I THINK I can tell where one description ends and the other begins, but if you could put each in its own subsection (6.1.1 and 6.1.2), that would be easier for readers to navigate.

In Section 6.2,

  This means that forwarder or producer cannot
  initiatively inject unrequested data.

I had to check, but “initiatively” is a perfectly good English word that I was not familiar with. I’m understanding the text, the sentence might be clearer as

  This means that a forwarder or producer cannot
                  ^
  inject unrequested data packets on its own initiative.
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Do the right thing, of course.

In Section 6.2.1, I couldn’t parse this text, and I think I know why.

  On the other hand, if interest has a
  partial name without any coding vector information or NC packets have
  a same name,
  ^^^^^^^^^^^

Is this (I’m guessing)

  On the other hand, if interest has a
  partial name without any coding vector information or multiple NC packets
                                                        ^^^^^^^^
  have the same name,
        ^^^
?

In 6.2.3,

  In another possible case, when receiving interests only for source
  packets, the forwarder may attempt to decode and obtain all the
  source packets and store them (if the full cache capacity are
  available), thus enabling a faster response to the interests.

I didn’t understand how this works. Is this enabling a faster response to subsequent interests, which is what I would have guessed because of the references to storing and to a cache), or to a single interest? And if this is obvious, I apologize to the authors.

As an aside, 6.2.4 does an EXCELLENT job of saying

There are multiple strategies,
Here is what the multiple strategies are, and
Here are the advantages and disadvantages of each strategy.

This is the kind of presentation I was hoping for in my comment on 6.1 above.

This text in Section 6.2.5 was hard for me to parse, and I think I know why.

  NC operations should be applied in addition to the regular ICN
  behavior.  Hence, nodes should be able to not support network coding
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  (not only in forwarding the packets, but also in the caching
  mechanism).

Perhaps something like

  NC operations should be applied in addition to the regular ICN
  behavior.  Hence, nodes should should not perform network coding
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  (not only in forwarding the packets, but also in the caching
  mechanism).

Would be clearer? Or am I missing the point here?

In Section 7.2 (“Rate and Congestion Control”), I didn’t understand how the first sentence in this paragraph is connected to the second sentence in the same paragraph.

  As described in Section 6.4, NC can contribute to seamless consumer
  mobility by obtaining innovative packets without receiving duplicated
  packets through multipath data retrieval.  It can be challenging to
  develop an effective rate and congestion control mechanism in order
  to achieve seamless consumer mobility while improving the overall
  throughput or latency by fully exploiting NC operations.

Maybe the reference to seamless consumer mobility is confusing me. Is it correct to say

  As described in Section 6.4, NC can contribute to seamless consumer
  mobility by obtaining innovative packets without receiving duplicated
  packets through multipath data retrieval, and avoiding duplicated
                                            ^^^^^^^^^^^^^^^^^^^^^^^
  packets has congestion control benefits as well.  It can be challenging to
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  develop an effective rate and congestion control mechanism in order
  to achieve seamless consumer mobility while improving the overall
  throughput or latency by fully exploiting NC operations.

?

[Ballot comment]
I enjoyed reading this well-written and interesting draft.  It provides important information; it is clear on the promising areas of integrations  and also provides clear guidance on open or less tractable areas (e.g. it is clear that it can focus only on block codes and convolutional would need more design).  Ready to be an IRTF RFC.

[Ballot comment]
This is a solid document - it is clear on the promising areas of integrations it covers and also provides a roadmap to areas not yet well understood or tractable.

[Ballot comment]
One high level comment (which isn't anything that would prevent publishing or would actually need to be addressed before publishing): For me the motivation why NC is specifically beneficial for ICN is not clear. It rather seems to me that NC would be kind of equally beneficial to any other kind of network interaction scheme. Section 6 even notes that a base principe in ICN is that a "forwarder or producer cannot initiatively inject unrequested data" which seems actually to make the application of NC (where N stands for network) quite complicated. The approaches and consideration presented are fine and make sense, I'm just saying the synergy of specifically combining these two techniques is less clear to me.

One editorial point: For the ICN terminology you refer to RFC8793. For NC you have a rather lengthly list with terms which not necessarily are all used. Wouldn't it make sense to similarly refer to RFC8406 instead?

Nits:
- sec 7.2: "would be effective, an effective deployment approach" -> "would be an effective deployment approach"?
- Maybe spell out CS on first occurrence.

This document is the product and represents the consensus of the Coding for Efficient Network Communications Research Group (NWCRG). It discusses the use of network coding techniques for Content-Centric Networking (CCNx) and Named Data Networking (NDN), focussing on technical considerations, challenges, and research outputs.

After an adoption as RG Item document in Sept. 2018, the document went through regular updates and presentations during NWCRG meetings, as well as a RG Last Call (Sept. 2020), cross posted to the NWCRG and ICNRG mailing lists. It has also been carefully reviewed by the RG Chairs. I believe this document is now ready for IRSG review.

Vincent Roca, on behalf of Marie-Jose Montpetit

This document is the product and represents the consensus of the Coding for Efficient Network Communications Research Group (NWCRG). It discusses the use of network coding techniques for Content-Centric Networking (CCNx) and Named Data Networking (NDN), focussing on technical considerations, challenges, and research outputs.

After an adoption as RG Item document in Sept. 2018, the document went through regular updates and presentations during NWCRG meetings, as well as a RG Last Call (Sept. 2020), cross posted to the NWCRG and ICNRG mailing lists. It has also been carefully reviewed by the RG Chairs. I believe this document is now ready for IRSG review.

De: Vincent Roca
Objet: RG Last Call for "Network Coding for Content-Centric Networking / Named Data Networking: Considerations and Challenges"
Date: 7 septembre 2020 à 16:16:16 UTC+2
À: nwcrg@irtf.org, icnrg@irtf.org
Cc: Vincent Roca , Marie-Jose Montpetit

Dear all,

We would like to officially start a RG Last Call for the following I-D:
"Network Coding for Content-Centric Networking / Named Data Networking: Considerations and Challenges »
https://datatracker.ietf.org/doc/draft-irtf-nwcrg-nwc-ccn-reqs/

This Last Call is managed by NWCRG but is copied to the ICNRG group as well.

The call will end on Monday Sept. 28th (3 weeks).

Please read it and provide feedback to the authors (note that it already went through several reviews). Thanks in advance.

Regards,

    Marie-Jose and Vincent