YEALINK over the Internet to Asterisk

We configured 4 Yealink T46G over the internet to our Asterisk. When we receive an incoming call, in most of the time not all phones are ringing. When we pick up the call and try to forward the call to an other extension it sometimes keeps ringing and the other phone receive nothing or a wrong phone is ringing.
Nothing is blocked on my firewall.

Can somebody help me out please.

Regards

If the phones are behind a NAT and also asterisk is, you can try and use a stun server to avoid common nat issues. Just earch for a public stun server and fill the appropriate option in the Yealink web interface.

Ok thank you for your answer. In my Asterisk i have set my peer nat=yes Is that not enough?
Do you really think i need a stun server?

nat=yes, which is deprecated, in favour of more specific options, implements various hacks to get round issues with NAT, particularly when Asterisk is outside and the phones are inside. It is not necessary for a well behaved NAT configuration when Asterisk is inside and certainly not sufficient.

Define an stun server on the YeahLink phones, it is good idea if they are behind a natted network, also there are some settings on the asterisk side( sip.conf) needed, for exmaple nat=force_rport comedia

I defined a stun for all my sip phones but that didn’t work. When there is an incoming call only one Phone rings, sometimes two or three… I’m using asterisknow… it’s driving me crazy.

You said that you have nat=yes, have you configured the externip or externhost and the localnet parameters?

Yes i did. I edited my peer settings with nat=force_rport,comedia
My externip / localnet are filled in.