Using MAX (single or multi cellular) can i PPTP(vpn) to a WAN port but go out of the Cellular/3g/lte port?


I have a requirement where i need to access the Cellular Data network.
So if i enable the PPTP server(assuming MAX has a PPTP server) on a WAN port and connect to it using a PPTP Client.
I then want the client’s traffic to be routed via the Cellular Network. i.e. when the client goes to whatismyipaddress it should show him the Cellular’s public ip.?

Is this possible using Max? and since it has a failover/redundant sim slot:- can i configure it to be able to access the two cellulars using different VPN Client profiles…(i do not need to access them simultaneously…).

also does MAX support USSD…so that i can check the balance of the SIMs.

NOTE:- given the Cellular Network doesnt provide me a public(or natted) ip …i cannot PPTP to it from anywhere… thus i would connect a public IP to the WAN port and be able to connect from anywhere.




Our MAX series do support PPTP/L2TP for client VPN connections. The clients will route through whatever connection that they are connecting via L2TP/PPTP provided that the client has “Use Remote Gateway” checked under there L2TP/PPTP settings. So in your case, should they need to be routed out of the cellular connection, the cells would need to have Public IP’s. Otherwise if connecting to a WAN with a public, whatsmyip will show that WAN as the IP routing them out to the internet.

We do support USSD:


Hmm… well currently i am using a small-router(microtix- hosting the PPTP server and doing ip-masquerading) in between a dlink3g/4g(DWR-921) … and thus i am able to go out of the cellular network. Diagram as below.

I was hoping that your device would eliminate my need of having 2 physical boxes. (its much more convenient for me to roll out around the world).

Also as for the USSD:- is it possible to send a external CURL command(with authentication) to send a USSD string (and the http response should contain the ussd response?)


You can configure DDNS settings on our MAX router for that particular cellular connection (with comes with active+backup sim card slot), and it’ll reflect the IP of the active sim card. Does that work for your scenario?

P.S. I’m checking with my engineering team on your USSD enquiries.
Update: Can you elaborate more on what you want to achieve with this external CURL command?


Not clear what you mean by DDNS(is it something similar to‎) … however i dont think this would work. I have a very specific need to land on the WAN(isp) and then goout of the cellularNetwork.

The external CURL command for USSD is to be able to check the balance/usage of the SIM. As you can see in my diagram that the origin handset(establishing the PPTP connection) would use this CURL command(using an app) to be able to check the balance/usage of the SIM. (its not convenient to be able to give users the access to a router to check ussd balance).


Yes it is something similar to dyndns, in which you create fixed hostname, which will get updated periodically with the currently in used IP, which is dynamic.

As for your requirement I don’t think it’s feasible, as the destination IP (WAN ISP) and the return IP (Cellular) is different. Perhaps you can share more on the specific need you’ve mentioned?
If it’s just to have a fixed IP you can connect to, DDNS should be able to resolve that.

I must apologize in advance, as I haven’t got a lot of experience on USSD, so I don’t really catch what you meant there.
Basically you’re looking for a similar function on the router that can perform what your app is doing right now?