I have a customer that has approximately 450 locations that currently only have Dial Up (POTS) access. They would like to use the MX67C to provided a faster connection back for credit card transactions. There is no ability at these locations to get an any other type of data connection.
Question 1 - Can the MX67C but configured to only use the built-in Cellular back up as a primary link?
Question 2- If the answer to question 1 is yes, can SD-WAN be configured in this configuration? Or would I need an external cellular modem to plug into WAN 1 for SD-WAN to work?
From my experience the answer would be yes. I have not tested this with a 67C with cellular only though.
1- You can use a cellular modem at the very least to be a primary uplink, but it won't be marked as primary. It should actually work with the sim in the device so you shouldn't need the usb modem, but that would be worst case.
2- SD-WAN has worked for me when using a usb modem, so I would say yes it will work with the internal sim
Keep in mind my answers with this are with running for less than 30 days in these types of configurations, so I may not be aware of using this method long term. I have tested on a 64/65W/67 models with a cellular modem only. I don't believe you can mark cellular as primary, but while it is in use SD-WAN works.
Also to note if you are going to go this route of cellular to ethernet the 67C is probably not the best fit or most economic. I would recommend MX64 or possibly even Z3/Z3C depending on the device count behind the MX. Both are drastically cheaper and will most likely handle the needs depending on features and services needed.