How does the LPN node initiate the iv update?

[Young]

Hi support team,

I have searched the forum , the infocenter and the specification, but didn't find the relevant info about how a LPN node initates the iv update if a LPN node exhausts its sequence number firstly in the mesh network. 

In the network_enable() in the LPN example, beacon isn't enabled.   So  if a LPN node exhausts its sequence number firstly in the mesh network, will the LPN nodes initiate the iv update procedure?  OR 

Do the friend nodes or other non-LPN nodes do something for the LPN nodes' initiating iv update?  I searched the relevant info in the source code, but cannot find the clue.  Could you give any clue?

nRF5 sdk for mesh 5.0, s132, SES

[Young]

We are just trying to figure out a solution for the scenario like below, I believe some other customers also meet this kind of scenario.  In the network, there are a few LPN nodes which only transmit packets  and other nodes except for the LPN nodes only recevice these packets (no ack), so the LPN nodes will exhaust the sequence number sometime. When this happens, how the LPN nodes update the iv index and let other nodes iv update?  could anybody  give any advice?