Re: [WoT IG]: Issues with bi-directional communication for CoAP and other IoT-related protocols

Hello everyone,

I have just joined the group a couple of days ago. I am working at a
university in a small island in the East Coast of Canada. This place is
called Prince Edward Island. Maybe you have not heard it before. It is very
beautiful in the summer.

The discussions are very interesting and full of insights. I have learned a
lot. Especially the discussion related to bi-directional communications, I
think it touched the core of WoT architecture. I put in a few slides trying
to contribute somehow. Also hope to learn more from you. Please correct my
mistakes and wrong understandings.

Thank you very much,

Yingwei


On 18 November 2015 at 16:16, Nilsson, Claes1 <Claes1.Nilsson@sonymobile.com
> wrote:

> Currently I do not know the details here but I may be able to find out.
> Will come back if so.
>
>
>
> BR
>
>   Claes
>
>
>
> *From:* Isomaki Markus (Nokia-TECH/Espoo) [mailto:markus.isomaki@nokia.com]
>
> *Sent:* den 18 november 2015 17:49
> *To:* Nilsson, Claes1; 'Dave Raggett'; Jason Proctor
> *Cc:* Jaime Jiménez; Hund, Johannes; public-wot-ig@w3.org
>
> *Subject:* RE: [WoT IG]: Issues with bi-directional communication for
> CoAP and other IoT-related protocols
>
>
>
> Hi,
>
>
>
> Does anyone have real experience how the LTE (or 3G) networks supporting
> IPv6 actually work in this sense? For instance, have they dropped all
> firewalling so that e.g. TCP connections could be kept open without
> timeouts or even incoming TCP/UDP would be possible without creating a
> biding by outgoing traffic?
>
>
>
> That would be nice for device-to-cloud connectivity maintenance
> perspective, but might bring additional problems. My experience with some
> earlier non-firewalled/NATed cellular networks was that there was quite a
> lot of unsolicited traffic coming in (various sort of probes I presume),
> and that was quite disasterous for the device power consumption too, as
> each incoming packet caused the radio to jump to an active/connected
> channel for a while, and there was no way to do anything about this in the
> device.
>
>
>
> The best approach woud be if the device was able to control the firewall
> bindings by itself, but protocols such as PCP made for that purpose have
> seen very little (if any?) deployment.
>
>
>
> Markus
>
>
>
> *From:* EXT Nilsson, Claes1 [mailto:Claes1.Nilsson@sonymobile.com
> <Claes1.Nilsson@sonymobile.com>]
> *Sent:* Wednesday, November 18, 2015 10:55 AM
> *To:* 'Dave Raggett' <dsr@w3.org>; Jason Proctor <jason@mono.hm>
> *Cc:* Jaime Jiménez <jaime.jimenez@ericsson.com>; Hund, Johannes <
> johannes.hund@siemens.com>; public-wot-ig@w3.org
> *Subject:* RE: [WoT IG]: Issues with bi-directional communication for
> CoAP and other IoT-related protocols
>
>
>
> Yes, this depends on the context. An example when an IoT device connects
> directly to the cloud is a device running LTE MTC, i.e. it is directly
> connected to the mobile network and has an IPv6-address.
>
>
>
> BR
>
>   Claes
>
>
>
> *From:* Dave Raggett [mailto:dsr@w3.org <dsr@w3.org>]
> *Sent:* den 17 november 2015 19:28
> *To:* Jason Proctor
> *Cc:* Nilsson, Claes1; Jaime Jiménez; Hund, Johannes; public-wot-ig@w3.org
> *Subject:* Re: [WoT IG]: Issues with bi-directional communication for
> CoAP and other IoT-related protocols
>
>
>
>
>
> On 17 Nov 2015, at 18:13, Jason Proctor <jason@mono.hm> wrote:
>
>
>
> greetings all
>
>
>
> IMHO, the assumption that the device still has the same IP address as it
> had the last time it and the cloud server communicated is problematic.
>
>
>
> in my mind, for various reasons, there will likely be a proxy server on
> the same network as the device, whose job it is to proxy stuff on behalf of
> an entity requesting access (it might also do some auth, etc).
>
>
>
> so the device communicates its abstracted address (eg
> HeartMonitor._wot._tcp.local for mDNS) to the cloud server, facilitating an
> address-neutral discovery on the way back. the proxy could also set up port
> forwarding etc for the duration of the connection.
>
>
>
> On Tue, Nov 17, 2015 at 3:39 AM, Nilsson, Claes1 <
> Claes1.Nilsson@sonymobile.com> wrote:
>
> Hi Jaime,
>
> The slides are here:
> https://lists.w3.org/Archives/Public/public-wot-ig/2015Oct/att-0104/Issues_with_bi-directional_communication_for_CoAP_and_other_IoT_related_protocols.pdf
>
>
>
> This will depend upon the context.  In some cases, having a local powered
> gateway/hub that sits between the cloud and the IoT device is the way to
> go. This makes it easier to deal with sleepy devices, strong security, and
> to preprocess/multiplex sensor data to reduce the load on the cloud server.
>
>
>
>  In other cases, the IoT device will connect directly to the cloud.
> Maintaining a “connection” through a NAT Firewall has its costs, so some
> such devices will be directly connected. A hybrid approach has the firewall
> in the cloud. With growing interest in low power wide area networks for
> sensors, that could be an increasingly popular choice.
>
>
>
> —
>
>    Dave Raggett <dsr@w3.org>
>
>
>
>
>
>
>