Please help with setting up openwrt luci 15.05 for a sip phone to work?

Question

Telephony

Good afternoon,
this question is ancient, but on the Internet, the solutions to the issue are different and do not always work.
Please help with setting up firewall and openwrt luci for sip phone to work.
After installing additional packages, a 3g modem from a megaphone on the wan interface installed via the web. The Internet appeared, but the phones flatly refused to register with Rostelecom. After demolished all the rules and set the permissions in the web on the firewall to allow everything from lan to wan and back.
Phones registered, but when dialing 403 forbidden.
Tell me what to look at or before you need to install.

Answer 1

Phones need port forwarding. https://wiki.sipnet.ru/index.php/%D0%A2%D1%80%D0%B...