Wednesday, April 3, 2013

The state of mobile VOIP, part 1


I recently made another effort to get VOIP working on my cell phone. I had acquired a new phone with Ice Cream Sandwich, Google's latest Android software, but hadn't set-up its cell provider yet. I had many reasons for setting up VOIP but not having a provider yet gave me an extra incentive to see if I could get reliable enough service without one. The goal was to be able to make and receive calls without a cell provider. Perhaps later, if I got a cell provider, the goal would be to be able to make and receive calls over a data connection without using minutes.

My other reasons for wanting to set-up VOIP were:
  • better quality - Legacy phone networks (and even VOIP duplicating the G.711 standard) only sample 8 bits at 8kHz. This is crap compared to, for example, Speex which can sample up to 32kHz! Granted, sampling rate isn't everything but at least its an improvement.
  • video - Optimally, if the dialler realized that it was calling a VOIP peer, it could place a video call.
  • encryption - Some clients can strongly encrypt which is nice because we now know that, even in the US, the government is actively listening to phone calls.
  • price - Theoretically, calls over wifi are free, but even if you need a provider, prices of 2c a minute are common. 500 minutes a month is only $10.
What are our options ? Here is an abbreviated history of videoconferencing.
  • H.323/Netmeeting - This was the first widely used videoconferencing technology. It was created before firewalls and NAT, however, and it is fairly proprietary so it is infrequently used (outside of pure Windows houses.) I mention it for completeness' sake.
  • SIP - This was the first standards-based protocol to see widespread adoption. It is still used heavily today. However, it too was created before NAT and so needs help to slip into most networks.
  • Skype - This is probably the most used videoconferencing tool. It has good quality and security, and has NAT traversal built-in, but it is proprietary.
  • Google Talk - Google's proprietary "social instant messaging" protocol can be used as a videoconferencing or telephone tool.
  • IAX - Inter-Asterisk Exchange is a semi-open protocol that, like Skype, was designed post-NAT, however support for it is quite rare in the mobile market. I mention it for completeness' sake.
A recent addition is Republic Wireless. It is attempting to market what I am trying to do homebrew: seamlessly move between networks (and use the cheapest, highest quality choice available) without callers realizing.

I will describe my trials and tribulations trying to use most of these technologies in the following posts.

No comments:

Post a Comment