# Network watchdog vs Cellular watchdog vs Active SIM firmware switching question

**URL:** <https://forum.sierrawireless.com/t/network-watchdog-vs-cellular-watchdog-vs-active-sim-firmware-switching-question/21772>\
**Category:** AirLink routers\
**Created:** [October 12, 2020, 2:22pm UTC](https://forum.sierrawireless.com/t/network-watchdog-vs-cellular-watchdog-vs-active-sim-firmware-switching-question/21772 "2020-10-12T14:22:01Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![JayK](https://avatars.discourse-cdn.com/v4/letter/j/e47774/32.png) [@JayK](https://forum.sierrawireless.com/u/JayK)\
**Post date:** [October 12, 2020, 2:22pm UTC](https://forum.sierrawireless.com/t/network-watchdog-vs-cellular-watchdog-vs-active-sim-firmware-switching-question/21772/1 "2020-10-12T14:22:01Z")

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I am using an RV50X with AT&T SIM as Primary SIM, and Verizon SIM as secondary SIM

Reading the manual, I don’t quite understand how to properly set the Network watchdog, Cellular watchdog, and “Active SIM based firmware switching” features with my current setup.

End goal is to have the ATT SIM as being active as much as possible, and Verizon SIM to be used only when the ATT connection is not working.

To begin with, should I enable “Active Sim based firmware switching” since I have an ATT and a Verizon SIM in the device? The device seems to be able to use either SIM while using an ATT radio module firmware, so I’m not sure when this setting should be enabled.

I currently have Automatic SIM switching settings as follows:

 ![image](https://us1.discourse-cdn.com/flex025/uploads/sierrawireless/original/2X/8/881fd47f11d0d19620fe264cc6f3520316087079.png)

Is this improper? Manual seems to say “Scan timeout” should be “0” if i’m using active sim based firmware switching

what throws me off is that the manual ALSO says that Scan Timeout should NOT be zero if i want automatic sim swiching to occur. Which I do.

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**Author:** ![Donald](https://avatars.discourse-cdn.com/v4/letter/d/ac8455/32.png) [@Donald](https://forum.sierrawireless.com/u/Donald)\
**Post date:** [October 13, 2020, 1:02pm UTC](https://forum.sierrawireless.com/t/network-watchdog-vs-cellular-watchdog-vs-active-sim-firmware-switching-question/21772/3 "2020-10-13T13:02:00Z")

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Hi @JayK

> [@JayK](#):
>
> The device seems to be able to use either SIM while using an ATT radio module firmware

If the device is able to use either SIM while using an ATT radio module firmware, You don’t need to enable “Active Sim based firmware switching”.

> [@JayK](#):
>
> End goal is to have the ATT SIM as being active as much as possible, and Verizon SIM to be used only when the ATT connection is not working.

You can increase Service Loss Time out and decrease Non-primary Network Timeout.

> [@JayK](#):
>
> Is this improper?

Yes, it is.

Please refer to page 78 → 83 in AirLink RV50/RV50X Software Configuration Guide for more details.

You can get this document here [AirLink RV50/RV50X Software Configuration Guide](https://source.sierrawireless.com/resources/airlink/software_reference_docs/airlink-rv-series---configuration-guide/#sthash.R6Q7APJY.dpbs)

Please help to tick “Solution” if your question is answered.