Is this SD-WAN over LTE? Can LTE be used as the primary uplink?
No. LTE link can be used as failover or single-uplink only.
Source:
https://documentation.meraki.com/MX/MX_Overviews_and_Specifications/Z3_and_Z3C_Overview_and_Specific...
The Z3(C) is built for home office users that need to AutoVPN into the office or very small offices. It is therefore recommended to have no more than 5 LAN clients connected to it. Have a look at this table:
| | Z3(C) | MX64 |
| Recommended Maximum LAN Clients | Up to 5 | Up to 50 |
| Max Stateful Firewall Throughput | 100 Mbps | 250Mbps |
| Max VPN Throughput | 50 Mbps | 100Mbps |
MX's can also have the Advanced Security license which gives them additional next-gen firewall features (IDS/IPS, Malware Protection, geobased firewalling, content filtering). More info about that here: https://documentation.meraki.com/MX/Other_Topics/MX_Security_Appliance_FAQ#Advanced_Security
MX's can also have 2 WAN links, even the MX64, being the smallest model can use one of its LAN links as secondary WAN. You can then do SD-WAN with them.
The built-in cellular in MX can never be used for load balancing. For that use case, the MG21 gateways can be connected to physical WAN links of MX.
