Re: [dnssd] Review of draft-ietf-dnssd-mdns-dns-interop-04

[Tim Chown <[e-mail]>]

Hi Ines,

Many thanks for this review.

As you’ve implictly noted, the focus of draft-ietf-dnssd-mdns-dns-interop-04 is interoperability of the labels used, primarily between unicast and multicast DNS.

You raise some very good points about the efficiency of mDNS/DNS-SD, particularly in constrained environments. This isn’t something we’ve covered in any detail as yet in the dnssd WG, aside from draft-aggarwal-dnssd-optimize-query-00 being presented a few IETFs ago, but DNS-SD in mesh networks is in our charter (https://datatracker.ietf.org/wg/dnssd/charter/ <https://datatracker.ietf.org/wg/dnssd/charter/>). To date we’ve focused on enterprise and home networks as managed and unmanaged multi-link IP environments. 

It would be useful to explore potential issues with DNS-SD in constrained environments further. Is there someone who might be at Chicago and able to raise this issue in our meeting, briefly?  We could make some time for this topic. That might then help seed further work.

Tim (dnssd co-chair)

> On 14 Mar 2017, at 19:09, Ines Robles <[e-mail]> wrote:
> 
> Reviewer: Ines Robles
> Review result: Ready
> 
> Hi,
> 
> I have read the draft. The document provides a description of the
> requirements for a profile for label interoperation.
> 
> In IoT, networks and nodes, in general, have constrained resources.
> Related to the topic of the draft in review, several aspects should be
> considered from IoT point of view, such as:
> 
> - Type of devices that have insufficient resources to run DNS-SD/mDNS
> [1] (Some running code [7]). The work in [2][3] depicts an
> autoconfiguration scheme for the global (or local) DNS names of IoT
> devices. It uses an specific DNS Name Format
> (unique_id.object_identifier.OID.domain_name).
> 
> - Resource Directory (RD): A web entity that stores information about
> web resources and implements the REST interfaces for registration and
> lookup of resources. A mapping between CoRE Link Format attributes and
> DNS-Based Service Discovery aspects (mapping ins to <Instance>,
> Mapping rt to <ServiceType> and Domain mapping) is descripted in
> version 9 of RD draft [4]. 
> 
> - Optimization of DNS-SD: A proposal for an optimization of DNS-SD
> query using TXT records is descripted in [5].
> 
> - DNS Message Compression [6], implemented in uBonjour Contiki.
> 
> Thus, new work (or updates) is needed to set the requirements for
> label interoperation in this type of environments. I understand that
> this is out of scope of dns-interop draft. So, what about to add in
> the dns-interop draft some text like:
> 
> "Related to constrained environments, work is ongoing such as
> autoconfiguration[2], optimization of DNS-SD [5] and DNS message
> compression [6] that would help to get an efficient selection of
> labels for DNS and other resolution systems."
> 
> Hope that it helps.
> 
> Cheers,
> 
> Ines.
> 
> 
> [1] https://www.ietf.org/mail-archive/web/dnssd/current/msg00589.html
> [2] https://tools.ietf.org/html/draft-jeong-its-iot-dns-autoconf-01
> [3] Lee, Sejun, Jaehoon Paul Jeong, and Jung-Soo Park. "DNSNA: DNS
> name autoconfiguration for Internet of Things devices." Advanced
> Communication Technology (ICACT), 2016 18th International Conference
> on. IEEE, 2016.
> [4] https://tools.ietf.org/html/draft-ietf-core-resource-directory-09
> [5]
> https://tools.ietf.org/html/draft-aggarwal-dnssd-optimize-query-00
> [6] Klauck, Ronny, and Michael Kirsche. "Enhanced DNS message
> compression-Optimizing mDNS/DNS-SD for the use in 6LoWPANs." Pervasive
> Computing and Communications Workshops (PERCOM Workshops), 2013 IEEE
> International Conference on. IEEE, 2013.
> [7] https://github.com/Agile-IoT/awesome-open-iot#mdns--bonjour
>