Forum Discussion

DaveD-VA's avatar
DaveD-VA
Roaming Rookie
11 months ago

VOIP Stopped Working

For a year I had been successfully using VOIP on TMHI with an OBI200 and VOIP.MS. My VOIP stopped a couple of weeks ago.

After spending hours with VOIP.MS support (very helpful support, stuck with me!) and replacing the OBI device with a Grandstream HT801, I’ve still not been able to get VOIP to work.

The support team and internet searches point to TMHI as the problem., They changed something recently. TM support is no help, and denies any problems with VOIP services.  Their solution is to reboot!

I’ve tried forum suggestions about using encrypted connections, with no luck.

Before I cancel TMHI, any help?

  • smihaila's avatar
    smihaila
    Network Novice
    2 months ago

    Hi,

    I'm in the same boat as the OP.
    My VOIP-based landline is with voip.ms and Obihai Obi100 SIP ATA hardware device.

    It was working PERFECTLY with Comcast Xfinity Internet.
    I've got the T-Mobile Home Internet a day ago, and currently trying it out.

    Nothing works in terms of VOIP: neither outbound, nor inbound calls.
    The voip.ms customer support suggested enabling encrypted SIP (via the S-RTP protocol). Still doesn't work.

    It's probably something related to T-Mobile's WAN / network using a CG-NAT (Carrier-Grade NAT) and not assigning a true public IPv4 address. So SIP ATA devices may get confused about what the public IP is, thinking that the IPv4 observed from the WAN may be a public / fully-routable IP.

    It may also be that T-Mobile's internal network is actively filtering the UDP 5060 and 5061 ports, on either inbound or/and outbound. And well, we can't just ask VOIP providers such as voip.ms, to just make their SIP registrar servers and RTP media servers on other ports, just to mitigate T-Mobile's potential port filtering!

    If I cannot get my VOIP-based MAIN phone landline working, I'm so sorry, but I'll have to cancel this T-Mobile Home Internet Service.

  • tns1's avatar
    tns1
    Newbie Caller
    5 months ago

    I was planning on adding an OBI or Grandstream box to the Sagemcom gateway I just set up so I'd like to know this can work.

    What gateway are you using? Any other wired equipment you have connected besides the VOIP box?

  • pjo1966's avatar
    pjo1966
    Network Novice
    5 months ago

    Did you ever get a resolution or did you bail on TMOHI? I'm in kind of the same boat. I just signed up for VOiP.ms for our "land line". It's the number the call box uses for me to buzz people in. I can make calls using VOiP.ms but can't receive. I'm seriously thinking of moving everything to Spectrum if I can't get this figured out.