Robin Good discusses open standards and suggests practical ways users can make a difference, including a discussion of SIP/VoIP:
Standards historically benefit the public at large.
As mentioned above, examples may include TCP/IP itself, email, ethernet, Wi-Fi, and many others. They usually win on their own, as a result of their natural benefits.
However, there have been a few cases where a proprietary solution has become dominant.
In the online collaboration industry a major example of a proprietary solution becoming dominant is the world of instant messaging, where instead of interoperable standards, we have several corporate islands competing with each other, and a few companies in complete control (such as when AIM shuts down access from MSN, or some other competitor).
Skype, for the all of the good that it appears to have brought to many of you, represents also a similar threat to VoIP.
In the end, SIP has to thrive on its own merits and we will see shortly how it will score on this front.
I know I would prefer to gift my children a world in which VoIP was based on open-interoperable SIP, rather than one based on any closed proprietary Skype-like system, under the control of a single private corporation.
Good stuff Robin. The SIP/VoIP topic is just one of many covered in Robin’s nice post.
For a primer on SIP, see the SIP Wiki which has lists of free services and various SIP-compatible hardware/software products.