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Posts: 10
Registered: ‎04-17-2017

Procedure for zigbee Router rejoin

Hello,

 

I am Vinay, from Samsung. Currently I am trying to understand the rejoin behavior of router devices.

I currently have a coordinator and a router device in my zigbee network. For the router to rejoin, I switched off the router and I changed the channel of the existing router and waited for the router to rejoin for > 30 minutes. The router did not rejoin. I am not sure if this is the right behavior to see the rejoin requests from the router.

 

I read in this documentation https://www.silabs.com/documents/public/user-guides/UG105.pdf that

the rejoin behavior  if

due to a weak/missing connection between
parent and child, changed PAN ID, changed network key, or changed channel

 

Kindly enlighten me about reproducing the rejoin behavior for router zigbee devices. 

Posts: 144
Registered: ‎11-06-2014

Re: Procedure for zigbee Router rejoin

Hi Vinay,

 

Could you detail the method of how you change the channel of the current network, and how you perform the rejoin (APIs or CLI used, etc.)?

 

Thanks,

Yuping

Posts: 10
Registered: ‎04-17-2017

Re: Procedure for zigbee Router rejoin

Hi Yuping,

 

Thanks for the reply.

I can Telnet to the coordinator. Since I have information of the present channel, I can send a command to the coordinator to change the channel to a new one.

 

Here are the details steps from scratch:

 

1) Join the Router to the coordinator.

2) Power of the Router.

3) Power off the coordinator for 20 minutes.

4) Power on the coordinator.

5) Change the channel of the coordinator once it is on line .( By telnet command )

6) Start sniffing in the new channel .

7) Power on the router device .

 

Expected result :

Router device tries to search for the coordinator with the same PAN in a new channel.

 

Actual result :

Router device does not rejoin and stays in the old channel.

 

There is no control over routers as they are devices from Market. We cant do anything here.

So we wanted to understand how to rejoin the router to coordinator.

 

If these steps wont help, we need your help in providing guidance for bringing rejoin of routers.

 

 

 

Posts: 10
Registered: ‎04-17-2017

Re: Procedure for zigbee Router rejoin

Dear Admin,

 

Can anybody help us here ? This is an important step for Samsung to understand the behavior of zigbee devices.

 

Thanks,

Vinay

<a href="http://community.silabs.com/t5/Welcome-and-Announcements/Community-Ranking-System-and-Recognition-Program/m-p/140490#U140490"><font color="#000000"><font size="2">Hero</font></font> </a> YK
Posts: 107
Registered: ‎02-13-2017

Re: Procedure for zigbee Router rejoin

Zigbee router doesn't scan channel during power on if it had joined a Zigbee network. Before coordinator changes channel, it should send notification to all of devices including router in the network.

Posts: 10
Registered: ‎04-17-2017

Re: Procedure for zigbee Router rejoin

Thank for the response.

 

By looking at YK's comments we cant see the rejoin of routers by changing the channel.

So what is the method for forcing the router to rejoin.? 

 

I am basically looking for 

 

a) How the network should be formed like how many routers should be in place 

b) should the coordinator be switched off for a particular duration etc 

c) should the router be moved to a farther location etc .

 

Since the routers are from different manufacturers we need a plan / steps which would help 

us to see this rejoin behaviour. ( We are trying to see rejoin messages in the Sniffer )

 

Posts: 10
Registered: ‎04-17-2017

Re: Procedure for zigbee Router rejoin

So we need help in formulating a method for rejoin behaviour for these router devices.

We have devices from different manufacturers namely

Jasco, Osram, Sengled etc . 

<a href="http://community.silabs.com/t5/Welcome-and-Announcements/Community-Ranking-System-and-Recognition-Program/m-p/140490#U140490"><font color="#000000"><font size="2">Hero</font></font> </a> YK
Posts: 107
Registered: ‎02-13-2017

Re: Procedure for zigbee Router rejoin

I suggest you to search Mgmt_NWK_Update_notify and Mgmt_NWK_Update_req in Zigbee spec to study the channel interference and change topic.

Posts: 10
Registered: ‎04-17-2017

Re: Procedure for zigbee Router rejoin

Thank you @YK We will go through the topics.

However is there any way to make the router rejoin ?

<a href="http://community.silabs.com/t5/Welcome-and-Announcements/Community-Ranking-System-and-Recognition-Program/m-p/140490#U140490"><font color="#000000"><font size="2">Hero</font></font> </a> YK
Posts: 107
Registered: ‎02-13-2017

Re: Procedure for zigbee Router rejoin

Unless you clear network information and reset router, router won't scan channel to rejoin.
Posts: 10
Registered: ‎04-17-2017

Re: Procedure for zigbee Router rejoin

@YK: ok by resetting the router we are making sure it looses its previous link key, PAN info etc and hence it would search in all the channels. We would try this method. Thank you.

 

I have another question here

Does the router rejoin without making any of these changes to it ? Because we have been trying

different possibilities like move coordinator to a farther location , or switch off the coordinator  for a long time and switch it on again or like disconnecting the router under test for a day or two and connect it back to the network. In all these methods the router was able to talk to ZC all the time as if nothing has changed.

 

 

<a href="http://community.silabs.com/t5/Welcome-and-Announcements/Community-Ranking-System-and-Recognition-Program/m-p/140490#U140490"><font color="#000000"><font size="2">Hero</font></font> </a> YK
Posts: 107
Registered: ‎02-13-2017

Re: Procedure for zigbee Router rejoin

This is how mesh network works. Why do you expect different behavior?
Posts: 10
Registered: ‎04-17-2017

Re: Procedure for zigbee Router rejoin

What we were expecting out of this experiment is to capture rejoin request from zigbee routers not necessarily performing all-channel scan. Your method might not trigger a "Rejoin Request " from a router as resetting a router would have cleared network information and hence make as a fresh one. 

 

So could you suggest any other method ( not necessarily involving channel change ) to achieve a capture of Rejoin request from Zigbee router ?

 

<a href="http://community.silabs.com/t5/Welcome-and-Announcements/Community-Ranking-System-and-Recognition-Program/m-p/140490#U140490"><font color="#000000"><font size="2">Hero</font></font> </a> YK
Posts: 107
Registered: ‎02-13-2017

Re: Procedure for zigbee Router rejoin

There's no rejoin mechanism in Zigbee router.
Posts: 10
Registered: ‎04-17-2017

Re: Procedure for zigbee Router rejoin

@YK : Thank you for your honest feedback and answers.

Posts: 10
Registered: ‎04-17-2017

Re: Procedure for zigbee Router rejoin

@YK is there a documentation or link or any relevant material for understanding why zigbee routers have no rejoin mechanism ?

 

<a href="http://community.silabs.com/t5/Welcome-and-Announcements/Community-Ranking-System-and-Recognition-Program/m-p/140490#U140490"><font color="#000000"><font size="2">Hero</font></font> </a> YK
Posts: 107
Registered: ‎02-13-2017

Re: Procedure for zigbee Router rejoin

I don't remember where I had read about this. You can try to read Zigbee specifications to see if it has related information.