Hi
After some work here, I got this log:
"%IPPHONE-6-REGISTER: ephone-1 IP:20.10.10.11 Socket:2 DeviceType:Phone has registered."
Sounds good right. The phone finally registered to the Router.
You can see the file I attached and let me explain what did I see wrong on your project.
On the Router, you did not need two interfaces. As long as you connected the L3 switch on the interface
FastEthernet0/1, you had to create the subinterface FastEthernet0/1.20, config the encapsulation dot1q on it and put the IP address 20.10.10.1 255.255.255.0.
Then, you Telephone config should looks like thiss:
telephony-service
max-ephones 4
max-dn 4
ip source-address 20.10.10.1 port 2000
auto assign 4 to 6
auto assign 1 to 5
This is it for the Router. For the L3 switch, you should put the interface with the Router in trunk mode. No need to L3 interface.
You also missed this line: "ip dhcp excluded-address 20.10.10.1 20.10.10.10". This line is important because it prevents the DHCP service to assign the IP address 20.10.10.1 or 20.10.10.2 to the Phone. This two IP address is already taken and should not be assigned to any other device.
Well, I think this is it.
