Hi Dominik,
I am glad that you find Californium to be of help for your work
J
Regarding your question: you are right in assuming that the direction Californium -> Device over a CGN does not work easily out-of-the-box. In
particular, it is hard to initiate communication with a device from the back-end. I am afraid, though, that there also is no silver bullet for solving these issues. I think it mainly depends on your use case at hand. Many IoT scenarios only require the periodic
transmission of sensor readings from the device to a (cloud) back end. These cases should work out-of-the-box as you already realized.
In order to be able to talk to a device from the back end side, one approach to keeping the CGN’s routers “open” is to periodically send a “heart
beat” message from the device to the back end. When using LWM2M this could either be done “explicitly” by frequent “update registration” messages sent by the device (LWM2M client) or “implicitly” by periodic “notifications” sent by the device for a resource
observed by the back end (LWM2M server). Using any of these approaches, you should be able to also send “requests” initiated from the back-end to a device.
BTW I think the Californium [1] or leshan [2] developer mailing lists would be a better place for continuing this discussion
J
[1] https://dev.eclipse.org/mailman/listinfo/cf-dev
[2] https://dev.eclipse.org/mailman/listinfo/leshan-dev
Mit freundlichen Grüßen/ Best regards
Kai Hudalla
Chief Software Architect
Bosch Software Innovations GmbH
Schöneberger Ufer 89
10785 Berlin
GERMANY
www.bosch-si.de
Mobile +49 (151) 54336335
Phone +49 (30) 726 112-145
kai.hudalla@xxxxxxxxxxxx
Registered office: Berlin, Register court: Amtsgericht Charlottenburg, HRB 148411 B
Executives: Dr.-Ing.
Rainer Kallenbach; Michael Hahn
From: iot-wg-bounces@xxxxxxxxxxx [mailto:iot-wg-bounces@xxxxxxxxxxx]
On Behalf Of Dominik Obermaier
Sent: Saturday, November 28, 2015 12:13 AM
To: iot-wg@xxxxxxxxxxx
Subject: [iot-wg] CoAP and CGN
First of all, congratulations to all people involved in Californium for the new release! I’m very excited about it and I took the opportunity to dig deeper into CoAP recently.
There is one thing I don’t understand about CoAP and Carrier-Grade-Networks (CGN). Let’s say there is a Californium cloud deployment, which serves mobile clients. How would
CoAP (which uses UDP by default if I’m not mistaken) work with CGNs? Would it be possible to traverse CGNs? Device -> Californium is obviously not a problem, but I can’t wrap my head around how the Californium -> Device way would work, since UDP hole punching
seems not to be a working and reliable option with CGNs.
Are there any experiences with that? My understanding is, that if CoAP is used with IPv6, there wouldn’t be a problem. I didn’t find any good resources on that topic, so
I would be glad if someone could clarify the current state with CoAP and mobile networks.
--
Dominik Obermaier
dc-square GmbH - Software Solutions
Innere Münchener Straße 30
84036 Landshut
Tel. +49 871 - 97506300
Fax. +49 871 - 97506329
Web. www.dc-square.de
Geschäftsführer Christian Götz, Dominik Obermaier
Registergericht Landshut, HRB 8906
USt.ID: DE283445184
