[OKCon-Programme] SIP calls & OKCon
wouter at freeknowledge.eu
Fri Mar 18 09:09:46 GMT 2011
as suggested at the last Programme Committee it would be preferred to
use SIP for internet calls over Skype. Below follows an introductory
explanation and some pointers.
We can use a conference room from the Free Knowledge Institute, which
can be reached by using SIP calling to: 880 at voip.freeknowledge.eu
The system will ask for this password: 1234.
Please test it before so you'll be sure you can reach it for the next
I hope it works out well for you! And be welcome at the telecom
*Call using the internet SIP standard*
*Why not Skype?*
Skype is a non-free piece of software that uses a secret and proprietary
protocol for making phone calls between its users. The phone network is
therefore owned and controlled by one company.
SIP (Session Initiation Protocol) is an open standard protocol for
establish phone conversations over the internet, and can be compared to
the SMTP protocol and is also defined by the IETF.
Thus a dynamic ecosystem of developers, users and phone companies is
emerging that bases on this open standard protocol.
*How do I use SIP?*
Many developers have made available software applications that implement
SIP. either published as Free Software or as non-free.
Several forms exist:
A. install a client similar to skype, set up an account and call for
free between all other SIP users, from that account provider and others
that use SIP.
B. like A but purchase some credit from a SIP enabled phone company that
let's you call to plan old telephone numbers.
C. install (or rent) a server with a software PBX (cf. phone central).
Asterisk is one of the most famous Free Software applications that does
this for you. Once you have such server installed, you can create your
own accounts, set up conference rooms and/or gateways to the plain old
D. buy a hardware phone that implements the SIP protocol and add your
personal SIP account(s) into it and use it with A, B and/or C.
See for example:
Blink is a useful app: http://icanblink.com/ but you can find many others.
FreeCall is one of those companies that let's you purchase credit
(mainly for calling mobiles) and (after buying initial credit) let you
call for free to most landlines in the world. http://FreeCall.com
The nice thing is to combine various forms. But maybe you want to start
Free Knowledge Institute /Unlocking the knowledge society/
Free Technology Academy /Online education about Free Software/
More information about the OKCon-Programme