How to replace NRF52840 Zigbee gateway?

[Bosemani_Raja]

Hello Devzone,

  I'm developing a Zigbee gateway using NRF52840 and ESP chip for wifi. NRF52840 it act as an coordinator.

I'm using nrf5_sdk_for_thread_and_zigbee_v4.2.0_af27f76 and segger embedded studio.

I formed a network and added few devices. My doubt is How can I replace gateway without touching end devices?

For example;

I added 50 end devices, Some condition that gateway is failed or some defect happen. Now I want to replace that gateway with New one.

But the problem is 50 devices. I can't take it again, rest and add to network. Instead of that can we use information of old gateway and store it in new one?

Is it possible? How can we do this?

Thank you

Best Regards

Bose

[AHaug]

Hi,

In both nRF5 SDK and in nRF Connect SDK ZigBee supports what is called a "distributed security network" where there are no centralized node (such as the coordinator) that manages security in the network. In the distributed network, each router can provide the network key to the joining device. Distributed security is a certified feature in the ZBOSS stack. You can start network steering on the router to make it create a distributed network. However, I am not sure if you can convert a network that is established as a centralized network (where the coordinator is the Thrust center and the only device that can let other devices in) to a distributed central network. I recommend investigating the documentation pages for details if that is possible: infocenter.nordicsemi.com/.../sdk_thread_zigbee_latest.html

Please be aware that there are some potential security problems with the transport key in distributed network. All routers and end-devices in a distributed network must be pre-configured with a link key, used to encrypt the network key when it is passed to a new device. There has been cases where it has been exploited that the keys were hard coded on the devices.

Kind regards,
Andreas

[Bosemani_Raja]

Hai Andreas,

   Thank you for your response.

           Distributed security network may useful if we are making Routers and End devices.

But Currently , I'm developing Coordinator and integrating third party ZigBee sensors and switches.

In this scenario the Trust center is coordinator. Then how can we replace the gateway? any possible way?

 

Best Regards

Bose

[AHaug]

Allright, thank you for clarifying.

Unfortunately no. If you intend to swap the coordinator/gateway after provisioning devices to the network, you will remove the only device able to provision new devices to that network. The network itself can exist and work without the coordinator as long as there is at least one ZigBee Router Device in the network, but you won't be able to commission new devices or do Trust Center related tasks including sharing the key to a new gateway/coordinator. 

If you want to change the coordinator, you will have to re-provision the other devices to the new network created with the new coordinator for the case with centralized security.

Kind regards,
Andreas

[Bosemani_Raja]

Hai Andreas

 Thank you for your Response.