Meraki MX68CW and Z3C with build in LTE modem as primary link

[pigeons]

Hi, 

Website is stating that both MX68CW and Z3C can use only 3G/LTE as failover only

Q: Can LTE be used as the primary uplink?

A: No, LTE is currently only supported as a fail-over link and should only be primary during a temporary WAN failure event.

whereas Meraki documentation says we can use "CAT 6 LTE modem for failover or single uplink"

I'm confused, please let me understand whether we can go with Z3C or MX68CW and LTE as the primary and only link 🤔 I recon it will work, but what about support?

[DarrenOC]

Hi @pigeons , we’ve used cellular  connections as the Primary link for some sites but only as a temporary solution.

You would have to connect both devices out to the cloud first and let them register via a traditional wired method.  Then insert the SIM, let the cloud register that. Then fail the device over to its cellular connection.

You can then move the devices around wherever you wish using the cellular connections.

[KRobert · Accepted solution]

For any built-in or USB cellular failover, the cellular is always a last resort option for the appliances. These options include the MX and Z3 "C" options and the USB failover port on each appliance. This is why the MX and Z3 appliances have separate sections for cellular uplinks and firewall rules.

This is where the MG21 cellular modem gateway comes in. The MG21(E) is one of Meraki's newest products that provide 4G cellular access and converts it to Ethernet copper so you can plug it into Internet ports 1 or 2 on the MX and Z3 appliances respectively. They are great and Internet WAN ports have a lot better failover rate (near instant) compared to the USB or built-in cellular options.

https://meraki.cisco.com/product/cellular/integrated-antenna/mg21/#

[Crocker]

Throwing in my 2 cents here.

We use a mix of MX67C and Z3C appliances at several small satellite sites spread across the state, running entirely over their internal cellular. We also have several MX67/Z3 (no internal cell) appliances as well.

This works well most of the time; However, we do occasionally have issues where a handful of sites (usually within a small geographical range of eachother) will go offline early in the morning. They will not recover automatically, but we can send somebody out to reboot them and everything comes back to life.

My pet theory (which I need to check against a Meraki resource) is that the built-in cellular on both models has a limited # of retry attempts when it loses its signal. After so many attempts (or after so long without a ping from a cell tower), they just give up and don't try again until they're rebooted.

We do not experience this problem at sites that have an MX67/Z3  + MG21 setup.