How to configure telephony in conjunction with Catalyst 3560 + CISCO CP-7940 + TP-Link TL-WR740N (openwrt)?

Question

linux

What is given:

• 10 CISCO CP-7940 telephones
  
• 1 CISCO 3560 switch
  
• 1 TP-Link TL-WR740N (OpenWRT 15.05) with Internet via DHCP
  
• Zadarma.com account with 10 internal trunks
  

A TFTP server was also launched (OpenTFTP on a laptop with Windows 10 in the router network) with firmware for phones/switch and phone configuration sketches in xml.
What you need:
So that the phones receive the Internet from the router, and the address of the TFTP server on the laptop to update the firmware and configurations.
I am a complete layman in networks, and I saw the console of a tsiska until today five years ago in a nightmare, so any help is greatly welcomed.
ZY: If someone has examples of a combat configuration for 7940, I strongly ask for a link to pastebin indicating the firmware version under which the configuration was written.
Thanks in advance, comrades.

Answer 1

I think it's worth looking towards dhcp options. In the option, specify on which ip the tftp server is sitting. Then reboot the phone and see what files the phone asks for via tftp (run the snif on the laptop). Most likely, a file with a MAC address in the title will be requested, and, well, software.