Hi Carlos, Thank you for your comments. We provide replies to those inline below. Best, Nils -----Ursprüngliche Nachricht----- Von: Carlos Bernardos via Datatracker <noreply@xxxxxxxx> Gesendet: Montag, 18. April 2022 09:24 An: int-dir@xxxxxxxx Cc: draft-ietf-raw-ldacs.all@xxxxxxxx; last-call@xxxxxxxx; raw@xxxxxxxx Betreff: Intdir telechat review of draft-ietf-raw-ldacs-10 Reviewer: Carlos Bernardos Review result: Not Ready I am an assigned INT directorate reviewer for draft-ietf-raw-ldacs. These comments were written primarily for the benefit of the Internet Area Directors. Document editors and shepherd(s) should treat these comments just like they would treat comments from any other IETF contributors and resolve them along with any other Last Call comments that have been received. For more details on the INT Directorate, see https://datatracker.ietf.org/group/intdir/about/ <https://datatracker.ietf.org/group/intdir/about/>. Based on my review, if I was on the IESG I would ballot this document as DISCUSS. I have the following DISCUSS/ABSTAIN level issues: - As stated by the routing review, I think the point of not having an specification of IPv6 over LDACS is a bit troublesome: "There is currently no "IPv6 over LDACS" specification publicly available; however, SESAR2020 has started the testing of IPv6-based LDACS testbeds." The main value of this document to IETF, in the context of RAW, is to understand the characteristics of IPv6 over LDACS and the requirements of aeronautical trafffic using LDACS in terms of reliability and availability. - Reply: First: Aeronautical communications as a whole is currently progressing from (plain old) ACARS, over the ATN/OSI (specified in the 90s) to finally, today the Aeronautical Telecommunications Network (ATN) over Internet Protocol Suite (IPS). Now, the most important detail here is that LDACS is a network access technology in the context of the Aeronautical Telecommunications Network (ATN) over Internet Protocol Suite (IPS). As such any user-data via LDACS is essentially ATN/IPS traffic. While we will update our draft with an explanation of the characteristics of IPv6 over LDACS, we believe LDACS reliability and availability have been explained in sufficient depth. - It is mentioned that handover between LDACS cells is seamless, automatic and transparent to the user --> does this mean transparency to the IPv6 layer? how is this done, what type of service/interface (and associated link model) do provide LDACS L2 to IPv6? I think the most relevant part of the LDACS protocol stack for the IETF is the section 7.3.3 (LDACS Sub-Network Layer and Protocol Services), which basically says that this is "ongoing work". - Reply: We can update the draft now with a specific explanation on how the handover work on LDACS protocol level. - "Technically the FCI multilink concept will be realized by multi-homed mobile IPv6 networks in the aircraft." --> how is Mobile IPv6 going to be used and which specific protocol of the Mobile IPv6 family? just MIPv6 and/or PMIPv6? implications on mobility and RAW are unclear at this point (probably this is for the RAW WG to evaluate, but just wanted to point it out). - Reply: PMIPv6 seems the most likely candidate at the moment. We will update the draft. The following are other issues I found with this document that SHOULD be corrected before publication: - The objectives of the document are not clear in the abstract. Since this is a RAW WG document, it is about explaining a technology that might be used by future RAW solutions, and the goal of the document is present its characteristics with that angle in mind. I think this needs to be better explained, to set the right reader expectations. I think it should also be mentioned that LDACS standardization is not actually finished, and therefore this document is a snapshot of current status. - Reply: The objective of this document is to make the Internet community aware of the ATN/IPS transition in aeronautical communications along with informing the community about the various access technologies providing ATN/IPS traffic. We will update the draft addressing your last two suggestions. - There is a lot of very good information about LDACS and context on aeronautical communications in the document, but I wonder if part of it should be maybe moved to an annex to keep tha main body focused on the actual implications to IETF (and specifically RAW) of the use of LDACS. - Reply: We believe that providing this exact context is of essential interest to the IETF, hence we strongly suggest to leave the document structured as is. The following are minor issues (typos, misspelling, minor text improvements) with the document. Just some below (I think other directorate reviews did a very good job identifying some): - "It assumes a star- topology in each cell where Aircraft Stations (AS) belonging to aircraft within a certain volume of space (the LDACS cell) is connected to the controlling GS." --> "It assumes a star- topology in each cell where Aircraft Stations (AS) belonging to aircraft within a certain volume of space (the LDACS cell) ARE connected to the controlling GS." - Reply: We will correct these. -- last-call mailing list last-call@xxxxxxxx https://www.ietf.org/mailman/listinfo/last-call
