Can find other players with internet box but can't with internet phone sharing

[Esanqueris]

Hello there !
After a lot of try to connect with a friend, we found out what the problem is, but we can't resolve it.

We finally found online players but only one of us could because if we are on the same internet connection, the last one to connect just crash.

So i tried to connect with my phone's internet (with a classic internet share) and then ... doesn't work anymore, i can connect but it never find anyone.

I already looked for answers and found nothing (so i'm sorry if this topic already exists, but i really didn't find).

If someone can help me, that would be great !

[AdamN]

Hello there !
After a lot of try to connect with a friend, we found out what the problem is, but we can't resolve it.

We finally found online players but only one of us could because if we are on the same internet connection, the last one to connect just crash.

So i tried to connect with my phone's internet (with a classic internet share) and then ... doesn't work anymore, i can connect but it never find anyone.

I already looked for answers and found nothing (so i'm sorry if this topic already exists, but i really didn't find).

If someone can help me, that would be great !

multiple device running PPSSPP each can't play multiplayer using the same router/internet connection with external adhoc server like sushicat, because your public IP will be the same and adhoc server like sushicat can only recognize 1 Player per IP

if you're using mobile data (ie. 3G/4G connection) to play it will most-likely failed to see each other, because most mobile ISP doesn't allow port forwarding, in this case you will need to use VPN to play multiplayer so the connection can be relayed

[Esanqueris]

Thanks for the answer.

I tried using free VPNs but i can't figure how to do.
Could you explain me how?