Router Openwrt Zerotier speed

[wazah]

Hello all,
First of all, zerotier is great!
I have 2 computers in 2 different locations were connected, both with zerotier. And easy to play lan games or transfer stuff to each other with 100% speed, maximizing the internet line.

Now I have succeeded installing openwrt with Zerotier on a router. So devices behind the router can also connect without the Zerotier client software.

Only running into a problem I only have like 25% of the speed, when computer behind the router transfers to computer on a different location.

I already opened up UDP 9993 on the modem after the router. But speed still cut off.

So I was thinking about possible solutions and things to try out.
And I want to tweak the router with Zerotier to bring it back to the 100% speed, or ofcourse other solutions

1: Can I for example also open up UDP 9993 on the router with Zerotier itself? or would that not make a difference?

2: Can I disable Nat on the openwrt router, or would Zerotier not work anymore? The modem behind the router also has Nat.

3: If I also startup Zerotier on a computer, which is also connected on the Router with Zerotier, would that conflict with each other?

4: Some other solution?

Thank you for reading and possible answers

[zt-travis]

Hello,
thanks for writing. You should allow ZeroTier on the router to do outgoing UDP. I’m not sure how to go about configureing that. You should be able to ssh into the router and check zerotier-cli peers and see if it’s making direct connections.
You might want to check CPU usage while ZeroTier is processing traffic. The router might just be under-powered compared to your PCs.

2. Behind Double NAT, ZeroTier will chaotically work and not work
3. That should be fine.

[wazah]

Thanks for your answer! I tried starting up Zerotier on a computer behind the router and indeed starts without conflicts. So that would be behind double NAT, but interestingly enough I get full speed again

That is a very useful command ‘zerotier-cli peers’. Thanks for that. I can see the router with Zerotier itself is ‘DIRECT’. And the computer with Zerotier behind the router is ‘RELAY’.
I’ll try your suggestion to tweak the router and check cpu.

[wazah]

Tweaked the router a bit, optimizing it. And succeeded getting the computer having a Direct connection through the router.
Tried a big file transfer and make the router with Zerotier sweat a bit, I saw the router cpu usage go to almost 100%.
So it’s clear to me now the cpu in the router is a bottleneck.
I didn’t know yet the router cpu played such an important role for transfer speeds, but I allready want to upgrade it

Do you maybe have a suggestion what kind of minimum cpu I would need in a router for Zerotier to work effortlessly? Like minimum Mhz and amount of cores?

Thank you for your answer!