Would NDIS off cause session to hang and not reconnect when supplier 3G connection is lost?

Hi Guys,
Looking for some assistance with a widespread issue we have.
We use Digi Transport WR21 routers with a SIM card using the 3G Network on each router.
When our 3G supplier has an outage and the connections drop and try re-connect, what we see is a large amount of connections that do not re-connect.

We have investigated this as much as we can think of.

The Event log does not show a PPP disconnect at the time of the issue.

If we drop the PPP link and bring it back up, the connection restores.

One setting which we do change from the default Digi one is change NDIS to off.
We put this in a number of years ago due to a bug at the time.

Could NDIS being turned off cause the device to not realise its connection has dropped and turn stale?
Struggling to find info on what the NDIS/Packet Data Connection actually does.

After any help possible!

Kind Regards,


the NDIS you should be using as it is ment to provide a faster connection .

if the problem is fixed by dropping PPP and re connectionf then you should be using surelink to monitor traffic on PPP if it sees a provlem it dropps PPP and reconnects.

this can be found under the wizards menu.

there is also as part of this a reboot feature on the number of bad attempts