Im currently a maxis fibre (Maxis own build infra) user which using a Huawei GPON HG8240H5 and a Tp-Link Archer c5v provided by maxis. I'm planning to replace the old tplink router, but the dect phone is connected to tel port on maxis router, and nowadays a lots of router like TP-link ax73 dont have tel port. So I'm trying to use the tel port on huawei modem, and i saw some unifi user connect their dect phone directly to modem. I'm not sure wheter can work or not, some maxis user say yes some say no.

I haved managed to logged into Huawei modem and do some configuration. But its not working, the tel port on modem blinking slowly. Anyone have tried success doing this?

This is some of my refrence:
gist.github.com/Anime4000/6bb17e4355574de8d4f01771359bfe5f

the Basic user paramiters sip password is copied from the old tplink router (revealed trough inspect)