Digium IP Phone D40 Quality, Very Bad

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Hi All;

Really it is miserable.

I bring 8 Digium Phone D40 and I used them with a customer, the voice quality is bad internally (between the extension), there is no clearance at all ! We are hearing the voice like another person.

The used codec is ulaw.

The firmware version is: 1_1_0_0_48178

Even at the web based configuration at the phone it self, I am not able to do reboot (there is no reboot button) and I can do this only from the Phone it self.

From the speaker, the voice is very bad and weak.

I am really feel disappointed why I did not use Polycom.

Can someone help me or advise me what to do in this?
Regards Bilal

4 thoughts on - Digium IP Phone D40 Quality, Very Bad

  • 1. I’m curious why you went with the Digium D40 vs Polycom? I assume from your post you have already successfully implemented Polycom phones on site.

    2. Did you not test the phones before going on site? If yes, what has changed between the two sites. I get the impression when you say
    ‘Really it is miserable’ this is the first time you have set them up and are truly surprised with the quality.

    3. There are many things that can affect audio quality. What have you done to isolate the specific issue to the Digium D40?

  • Many members of this list will testify that audio quality issues can happen on *any* SIP phone. Our support department regularly troubleshoots audio quality issues with many makes and models of phone
    (for those customers of our paid Asterisk Support). You can have a variety of audio quality problems caused from various root issues such as networking misconfiguration and even bad room acoustics or cheap headsets plugged into the phone.

    If only it were as simple as “buy this phone it’s good” or “don’t buy this phone it’s bad”. Unfortunately as we all know, technology is often more complex.

    In regards to rebooting the phone it sounds like you found the method within the phones physical interface. However, there’s no “reboot”
    button in the web GUI of the phone. There are two additional ways of doing it:

    1) (I’m not using the DPMA), see –
    You’ll send it a SIP NOTIFY telling it to reconfigure.
    2) (I’m using the DPMA), see –
    You’ll do digium_phones reconfigure phone …or… digium_phones reconfigure all

    Your best next step is to call Digium, the manufacturer of the phone;
    They offer *free technical support* on the Digium phones and can best help you troubleshoot the issue. For support call +1 (256) 428-6000 , option 2 and then 2 again.


  • I have no experience with the phone in question and so will make no comment regarding the OP’s original problem, but the absence of a software reboot function in the web GUI seems to be a pretty major oversight in my view.

    I do hope that one gets added to the “we should really add this to the firmware ASAP” list 🙂

    Kind regards,


  • Real question: Why are you needing to reboot your phones?

    You should never be getting the phone into a state where the only way out is to reboot it. The correct solution is *not* to make rebooting easier, but to avoid ever getting into that state in the first place.

    By the way, we have recently acquired some D40s. How do you change the time format from AM/PM to VCR-style? (i.e. 16:41, not 4:41 pm).