Recently switched to NBN50 via HFC with iinet, who also supplied TP-Link modem Archer VR1600v v2 in Dec 2019.
Firmware version 0.1.0.0.9.1 v5006.0 Build 190228 Rel. 72265n
We had successful install, stable NBN connection with expected speeds, excellent wifi - but intermittent failure of outgoing voip calls. Troubleshooting incl. changing phones, voip phone ports to no avail. Router phone port light is on, incoming call works, dail tone works, but on dialing any number, instead of connecting, you get a constant loud digital tone. Rebooting the router sometimes fixes the problem, but not always. It's intermittent, may take several reboots to work again, very frustrating.
When describing problem to iinet support, they're unable to help (not trained to assist on the device they supplied) and refer to manaufacturer TP Link. Support call to TP Link in early Dec advises to try firmware upgrade and if that does not work, we may have a router fault and they will replace the device. We are running the latest firmware. IT guy looked at router settings again yesterday, may have identified the issue: In router settings: Network Status - Advanced - Bandwidth Control - Telephony Bandwidth Guarantee, the 'Enable' box was unticked. Now enabled - no outgoing call issues since.
Welcome to the Community!
In as much as I would love to help with the homephone issue you've raised, but since you're on iiNet service, we don't have any way of checking the status of your VOIP service at our end. Please understand that though TPG and iiNet are under the same umbrella, we are still 2 separate entities, thus, have different databases.
I understand that you've already reached out to them previously regarding your initial concern about the intermittent outgoing calls, however, we suggest checking this with iiNet support once more. There are other possible reasons for Outgoing calls not to work (including but not limited to; account-related concern) which the iiNet team can look into first before checking the technical side of the case.
We may already have resolved this, but as it was difficult to troubleshoot - precisely because 2 different unrelated entities are involved - we posted the potential solution (check if router setting for telephony bandwidth priority is enabled). Hopefully it'll help others with the same issue.