Looking at the dozen most recently posted threads on this board, I see 1794 posts about Google Voice and only 30 on other topics. Something is very wrong with this picture. End users endure tremendous hassle for what, to save a few dollars each month? Though some of the main participants have business interests in this endeavor, most hope in that area seems to have faded.
A majority of home users and many very small businesses are mobile only. Though partly cost driven, IMO the primary reason is that fixed and mobile phones don't play well together. Mobile integration in Asterisk- and FreeSWITCH-based systems is awful. Larger businesses (where having a PBX is a given) often choose 3CX, RingCentral or other commercial products over open systems, because of better operation with mobiles. IMO none of these work well; they are just a little less bad.
What's needed is a system that makes 'mobile extensions' work well. Presently, an incoming call can be forwarded to a mobile SIP app, or as a normal voice call. Most SIP apps suffer from lost registrations, limited battery life, poor voice quality under less-than-ideal network conditions, dropped calls (IP address changes, etc.), non-operation behind many firewalls, security weaknesses and other issues. Though commercial apps have solved many of these problems, there is still a risk that when a call comes in, the recipient is in a location with poor data coverage and voice quality will be terrible. So, most users choose to forward over the cellular voice path, but that also has serious issues. If the caller ID is that of the original caller, you don't know it's a business call and may answer inappropriately. If the business number is sent, you don't know who's calling. To ensure that business calls don't go to mobile voicemail and the caller doesn't hear announcements in a language he may not speak, call confirmation (press 1 to accept) is needed, unsafe to do while driving. The added delay may result in the call being abandoned or going to voicemail. There is also significant quality loss, especially if the caller is also mobile, from cascaded compression codecs and from increased latency. Combined with e.g. caller in noisy bar, you on crappy car Bluetooth, one or both not speaking his native language, communication can become impossible. Outbound calls have additional DISA reliability and usability issues.
Though certainly not easy, it's IMO feasible to build a robust mobile integration system. It would consist of Android and iOS mobile apps and a matching back-end (server side) process. Simplified description: On an incoming call, server sends push notification, waking the app. During handshaking, server classifies internet connection as decent, poor or none. If decent, a VoIP connection is established with Opus codec, dynamically adjusting sample rate, data rate and FEC according to network conditions. On a 'poor' connection, a voice call is established only for the audio. Metadata such as 'Call for sales from John Doe' is sent over mobile data for display and controls such as Transfer, Conference and BLF keys continue to work normally. If there's no data connection, when the mobile call is answered, the server 'listens' for a key (such as one second of ringback tone) that the user recorded at the beginning of his mobile voicemail greeting, while simultaneously announcing metadata to the user. If the key is heard, the call is routed to PBX voicemail (or an assistant, etc.) Otherwise, the caller and callee are connected. If network conditions degrade during conversation from decent to poor or none, an announcement notifies the parties to wait a moment while the call is reconnected.
Would such a project interest Bill, Ward, naf or other members? I don't know how it should be organized from a business perspective. If purely open source, perhaps parties who stand to benefit such as Sangoma or Digium would provide funding. Of course, the apps could be for purchase or subscription and the server side could be a commercial FreePBX module. Or, the system with free or paid apps could be supported by a paid cloud service that could be used with any PBX or directly with a VoIP provider. A freemium model might work well here, similar to Sangoma's Zulu offering. You'd get up to two 'lines' free; larger organizations or families would pay.
Ironically, I'm using Google Voice right now, traveling where regulations limit me to a 'data only' SIM. Calls are forwarded to my Hangouts app -- it doesn't run the battery down, and quality is pretty good under most network conditions.
Finally, for the guys and gals who get their jollies from reverse engineering, how about a bridge between T-Mobile DIGITS and standard SIP? This would be an alternate (and in some ways better) solution to integration issues, albeit only for those with T-Mobile cell service.
Any comments or ideas welcome.
↧