[PANRG] 回复: Feedback on draft-zheng-panrg-path-properties-istn-00

[Zheng Shaowen <[e-mail]>]

Dear Spencer,



Thanks for pointing the issues out,  ATSSS_ph2 is about the procedures to support multi-access PDU session over the 3GPP and  non-3GPP accesses(e.g. satellite access), and it can be a good reference. And there are several related ongoing work item in 3GPP can be referred to as well, for example 5GSAT_ARCH.

This draft focus on the requirements and key issues on the TCP/IP and is a good complimentary of 3GPP’s work.

Thanks~

Zheng Shaowen

发件人: Spencer Dawkins at IETF<mailto:[e-mail]>
发送时间: 2021年3月12日 07:21
收件人: Theresa Enghardt<mailto:[e-mail]>
抄送: Peng Liu<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>
主题: Re: [PANRG] Feedback on draft-zheng-panrg-path-properties-istn-00

I wanted to chime in on something completely different ...

I'm glad the authors brought this work to PANRG. I think there's some overlap on these issues with 3GPP ATSSS_ph2, especially now that Rel-17 is including satellites as a way of expanding 5G coverage, and it will surprise no one that I think PANRG is well placed to look at the issues that will inevitably arise ...

Best,

Spencer

On Thu, Mar 11, 2021 at 11:12 AM Theresa Enghardt <[e-mail]<mailto:[e-mail]>> wrote:
(Sending this again because the recipients' mailbox rejected my mail to
the draft authors alias... Apologies if you get this twice.)


Dear draft authors,

Thank you for posting draft-zheng-panrg-path-properties-istn-00 and for
presenting it at the IETF 110 PANRG session!

I've read the draft and I agree that ISTN is an interesting field for
path awareness.

A few questions and comments:

1. The abstract says that the use case is "integrated space-terrestrial
networks". I think it should be more specific: Is the use case path
selection? Is it (also) something else? For path selection, does the
definition in Section 3.1 of the Path Properties draft fit your use
case, or are you missing anything from that
section? -> https://tools.ietf.org/html/draft-irtf-panrg-path-properties-02#section-3.1



2. In the introduction, the draft defines a path as a series of links
that connect a series of nodes from the source node to destination,
referring to RFC 5136. In Section 2, the draft lists path elements
corresponding to individual nodes and links. I think that's a good
starting point, but I'm wondering if a more generic definition would
work better. Then, path elements could be more abstract: Not just a
single node or link, but also an entire network, for example. This would
be useful, as the endpoint may not have insight into all path elements,
and it may be difficult to make every endpoint aware of every single
path element. So, would it be better to consider more abstract path
elements here, e.g., consider an entire network as a path element with
its own properties?


3. The draft considers properties of the entire path and properties of
each individual path element (node or link). I think it could be helpful
to consider subpaths as well, for example, the "space part" of a path or
the "terrestrial part" of a path, or the subpath traversing a specific
network. Then, a network provider could expose information about this
subpath, instead of exposing information about every individual path
element. What do you think?


4. The draft defines availability as a path property, which makes a lot
of sense to me. In contrast, the Path Properties draft defines a path as
a "sequence of adjacent path elements over which a packet can be
transmitted". Does this part of the path definition work for you? I
think the definition could be stretched to say "the path exists even
though a packet cannot be transmitted over it right now, but it will
become available again soon". Do you agree?


Thank you for the draft, and I'm looking forward to hearing more!

Best,
Theresa

_______________________________________________
Panrg mailing list
[e-mail]<mailto:[e-mail]>
https://www.irtf.org/mailman/listinfo/panrg