NRF9160 Modem library

[PBT]

Looking at the architecture for NRF Modem library here:

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/2.0.0/nrfxlib/nrf_modem/doc/architecture.html

I can see that there is an interface for sockets integrated with Zephyr using the "off load" API.
Now, since boards such as NRF9160DK  also has a short-range radio i would ideally have a setup with "forwarding" between
short-range radio and the cellular modem but that is not really feasible with sockets. 

There also seems to be an AT command interface - could this be used to create a driver in zephyr native stack?

Best
Peter

[Sigurd Hellesvik]

Hi Peter,

Our nRF9160: LTE Sensor Gateway sample forwards data from a Bluetooth Low Energy connection to LTE.
Is this what you are looking for?

If not, can you explain how what you are trying to do is different from this sample, so that I can understand your goal better?

Regards,
Sigurd Hellesvik

[PBT]

I want to have a gaterway that can forward IP packets from the native zephyr stack to the modem.
I'll need to look closer at the above sample but it seems to disable network in Zephyr so probably not 
what i want.

Thanks
Peter

[Sigurd Hellesvik]

Hi Peter,

Just to clarify, can you specify what this zephyr stack is for?
Maybe with a link to docs for said stack as well?

Regards,
Sigurd Hellesvik

[PBT]

I mean the Zephyr native IP stack.

Best
Peter

[Sigurd Hellesvik]

Hi Peter,

I discussed this with one of my colleguas, and I am afraid we do not grasp what you need yet.

Can you give a more detailed explanation of your end goal?

Regards,
Sigurd Hellesvik

[PBT]

uart:~$ net iface

Interface 0x200009b4 (IEEE 802.15.4) [1]
========================================
Link addr : F4:CE:36:D7:42:B4:67:77
MTU : 125
Flags : AUTO_START,IPv6
IPv6 unicast addresses (max 3):
2001:db9::1 manual preferred infinite
IPv6 multicast addresses (max 4):
ff02::1
ff02::1:ff7e:0
ff02::1:ff00:1
IPv6 prefixes (max 2):
<none>
IPv6 hop limit : 64
IPv6 base reachable time : 30000
IPv6 reachable time : 44104
IPv6 retransmit timer : 0

Interface 0x20000a20 (Dummy) [2]
================================
Link addr : 00:00:5E:00:53:99
MTU : 576
Flags : AUTO_START,IPv6
IPv6 unicast addresses (max 3):
fd00::f823:7f11:b1ba:7736 manual preferred infinite
IPv6 multicast addresses (max 4):
ff02::1
ff02::1:ff7e:0
ff02::1:ffba:7736
IPv6 prefixes (max 2):
fd00::f823:7f11:b1ba:7736/64
IPv6 hop limit : 64
IPv6 base reachable time : 30000
IPv6 reachable time : 27019
IPv6 retransmit timer : 0
uart:~$

[PBT]

Below i made a screendump from my Zephyr shell.
As seen there is two network interfaces - one is 802.15.4 and one is SLIP to a host.
In this case, since both networks are in the "native" Zephyr IP stack it is possible to set up routing/forwarding between these interfaces.

But if i add a socket interface as on 9160 modem library i can not see how i can achieve this.
(You could possibly do something for UDP but for TCP i cannot see it possible)

Does this make things clear?

Best

Peter

[Sigurd Hellesvik]

Hi,

Just to make sure that this is not an XY-Problem:

What is the problem you want to solve using this method?

Regards,
Sigurd Hellesvik

[PBT]

Well, i want to to "X" - IP routing. 
It would allow me to do "border routing" from one network such as 802.15.4  to LTE on NRF9160 device.
I  can do "border routing" from 802.15.4 to Ethernet on Nordic HW Such as NRF52840 using USB Ethernet. 

Best
Peter

[Sigurd Hellesvik]

Hi Peter,

We offer no implementation for a Border Router for the nRF9160.
But you know that, which is why you are trying to do it yourself.

I have been looking around, and not been able to find out how you can do this using AT commands.
I can neither promise that it is possible nor impossible though.

Regards,
Sigurd Hellesvik

[PBT]

Thank you Sigurd for clarification.
I think we can conclude the current status.

Best 
Peter