skip to Main Content

Digium’s New Phones: Are They Truly Open For Business?

A few days ago on Digium’s blog Malcolm Davenport posted some initial details about the companies new line of SIP phones. Malcolm’s post presents our first formal glimpse into the relationship between the phones and a new module for Asterisk called the Digium Phone Module For Asterisk (aka DPMA.)

You may recall that various folks from Digium were on a VUC call back on Feb 3rd, not long after the phones were announced and shown at IT Expo.

Friend Dave Michels had some nice coverage of the phones at point of launch. Dave also says some interesting things on his own site:

“It is actually a bit surprising that Digium is getting into branded phones directly that are proprietary even.”

…and further…

“It will be interesting to see if the open source community truly embraces proprietary phones – somewhat contrary to the creed.”

I’m not so sure I agree with his assertion that the phones are “propietary.” To my mind they are SIP phones with some extended programming capability. I would expect that to be more-or-less unique to the phones. The companies’ choice of Javascript renders them a more convenient target platform than might otherwise be the case.

So it was that I found myself a little confused about Digium’s phones when I tried to answer a question over at the DSL Reports VoIP Forum. Happily, both Malcolm and Steve Sokol jumped in to set the record straight. According to Steve:

“These phones are Digium originals. They are not OEM’d from anyone. We designed them ourselves. Our in-house design team did the plastics. Our engineering team selected the hardware components. Our software development team wrote the code. The underlying operating system is (unsurprisingly) Linux. The phones are being manufactured by a reputable contract manufacturer in China.”


“The DPMA or “Digium Phone Module for Asterisk” is an add-on module for Asterisk that adds some cool extra features including simple provisioning (they also support the old DHCP + FTP/HTTP process), and integration between apps running on the phone and core Asterisk apps. The DPMA enables visual voicemail, parking management, contacts directory, one-touch parking, etc.”


“Digium requires that users of the DPMA get a license key and accept a license agreement because the DPMA is commercial software. We do not and will not charge a fee for the DPMA.”

So DPMA is a closed source module, not unlike their G.729 codec or FAX module. The DPMA module is responsible for the provisioning of phones and handles all communication between Asterisk and the phones.

There have long been arguments comparing the merits of open APIs vs open source software. It seems that Digium has elected to keep DPMA closed source. It’s certainly a curious decision, but it is theirs to make. I do wonder if that approach will impact the level of interest/uptake from the developer community?

There will probably arise a few more points bearing clarification regarding Digium’s D Series phones and DPMA. I’m sure that Digium will provide further details once the phones are shipping in quantity.

This Post Has 6 Comments
  1. You don’t think proprietary is fair, but agree they are closed source. What’s the difference?

    Regardless though, I do like what they are doing. I don’t think proprietary is a bad word. Desktop phones need to evolve – they are always-on IP devices and should be capable of much more. My desk phone is 10 times the size of my super computer in my pocket (and hasmore power) and yet does much less. I love the idea of being able to run scrips on the phones.

    To sell these at first, Digium had to make them cheap. But I think the potential here is significant. Digium will likely be able to compete on value more than price as these evolve.

    1. The term “proprietary” carries nasty connotations…implies complete lack of interop, which simply isn’t the case.

      Polycom based their extended feature capabilities on an open standard called XHTML, but does that make the phones more “open?” I’m not so sure.

      Anyone wanting to leverage those advance features, in either case, is going to have to buy or develop something specifically for those phones. Both XHTML and Javascript are known qualities, accessible to a variety of toolsets.

      That presumes that Digium doesn’t charge for access to the API. That could be a regressive move. Yet they must be concerned about keeping their support burden manageable, which means not being distracted by hobbyists tinkering with trivial/pointless (non-revenue generating?) apps on the phones.

      All of this is about the very upper layer of special features, which may get used in frightfully few installs. Digium can do well with these phones even without the Javascript API, but that’s certainly the more interesting stuff. Beyond that, they’re just another family of SIP phones.

  2. I see the DPMA module as adding a layer of communication between open source (free) Asterisk and a physical device, and can understand the reasoning. If the module were totally open, then there would be nothing stopping other pieces of software from adopting the integration methods, and thus rendering the advantage to integrating the devices with Asterisk itself a moot point.

    From my understanding of Steve’s comment, the phones operate pretty much like every other SIP device that you would integrate with Asterisk or other SIP enabled software. Only when you use the (free, as in beer) DPMA module (which is closed) do you get some extra magic when you choose to integrate it with Asterisk.

    It seems like a winning situation to me for both the manufacturer who likely spent a not-insignificant amount of resources on developing a new product to sell, and the integrators of Asterisk to have some sort of leg-up on other integrators when bidding on jobs. The platform software is free for the integrator and incredibly flexible, letting the integrator win jobs that perhaps other integrators can’t, and the sponsor of the software is able to sell hardware into a realms where they wouldn’t otherwise be able to (mainly SIP-only environments where traditional PSTN connections are not being used).

    1. All very true. With the slow but sure demise of T-x connectivity on the horizon there needs to be a new revenue stream. End-points are a lot of the cost of any installation, so why leave those dollars for someone else. It makes perfect sense, even if it shifts the likes of Aastra, Grandstream, Polycom and snom from “partners” into “co-opetition.”

      However, DPMA as close source could be a problem from a security perspective. Provisioning end-points presents a major opportunity for evil-doers to penetrate an installation and work their evil tricks. If DPMA is not drum-tight it’s a serious problem. If it were open source it’d be more readily confirmed as secure by trusted, independent sources.

  3. I watched the demo of these phones presented on the VUC, but months later–not live.

    It’s really surprising that digum decided to make the phones with gray scale images and not have a color screen. This is likely to keep the cost down and to have a less expensive retail price, but it sets the phone back and may make others think this is something from the mid-2000s and not 2012. I had a mobile phone in the year 2000-2001 that was the first mobile phone with java and it had icons very similar to this phone.

    There’s no doubt this phone is powerful and built with asterisk and switchvox in mind; however I may be tempted for the polycom vx-500 even with its unusually large buttons because of the more modern look and (what I have been told) easy to navigate meun system.

  4. Ok, it’s ok if they make it proprietary, but I don’t think you should have to pay for it if you buy Digium phones (in case they wish to charge in the future). Asterisk is open source, and every vendor can feel free to develop their own equivalent plugin for Asterisk to do “magic” for their phones…

Comments are closed.

Back To Top
%d bloggers like this: