TLS/SRTP with Sangoma S500 and Cisco SPA508g

Hey guys, my first post here.

I have been trying to configure my pbx and my two lab phones to connect through tls/srtp connection but for some reason can only make it work with Zoiper.

I am using FreePBX 13, a Sangoma S500, Cisco SPA508g, and Zoiper app on my pc.

I have followed the wiki on how to set it up and only managed to get Zoiper to work with tls configuration. For some reason the phones do not want to work with it.

With Sangoma phone i tried both using an EPM and without it.

On the Cisco phone it should be pretty straight forward just change the port number and select tls instead of udp transport protocol.

What could possibly go wrong?

Thanks in advance foe your help.

Hello ,

This is an old Cisco post ,

an other key to this working , DO not change the port ( SIP ALG can help in transport issues )
DO not enable TCP , Enable TLS , force SRTP , and make sure your NAT is correct ,

Other than that i wish you good luck with your endeavor ,

Thank you in advance