Filed under General by Oscar Boykin | 3 comments
I have canceled my analog telephone service and moved to SIP based voice-over-ip. I am using a Linksys PAP2 device with the Gizmo Project/Sipphone (both owned by the same company).
The reason I went with Gizmo/Sipphone is that they have an open SIP network: I can use any device/software with my account. Many other providers do not let you use your own hardware or connect your own software to their network. Secondly, sipphone is very cheap. I don’t make many calls, but those I do cost 1 cent/minute (in the US). I pay 3 USD/month to get my phone number (904-224-1548). At this time, there are no other fees/taxes with Sipphone. This is substantially cheaper than my local phone company, but I also get more.
Other SIP users (using IP SIP phones or many open sip networks) can call me without either of us paying anything. In this case, the call is routed directly between their device/software and my device/software. Additionally, using a SIP softphone (like Twinkle which is included in Debian GNU/Linux), I can receive phone calls to my home number on my laptop. This means when I am traveling to a conference, anyone can reach me at my same home number at no extra cost to them or me assuming the conference has a good Internet connection.
Finally, one reason I wanted to move to voice-over-ip is the fact that it appeals to me to use an open, Internet-based protocol for all of my communications. I would hope for the same with cable television, but I know that copyright maximalists are going to DRM-ify TV-over-IP to the point that it will only be legally usable in closed proprietary systems. But the problems of DRM are another story (see Cory Doctorow’s talk [txt,pdf] and Defective By Design).
Update 6/14/06: I posted a review of my experiences with Sipphone.
Filed under Software by Oscar Boykin | 0 comments
I run Debian GNU/Linux on all my computers including my laptop. One problem I have had is that battery power is not as long as I would like on my laptop. One reason for this is that I have not been using the laptop-mode-tools package on my laptop. Now I am, and here is what I needed to do.
- apt-get install laptop-mode-tools
- edit /etc/laptop-mode/laptop-mode.conf to make: CONTROL_CPU_FREQUENCY=1
- edit /etc/modules to include “speedstep-centrino” and “cpufreq-ondemand”, and use modprobe to go ahead and load both of these modules
- Restart acpid (which was already installed): /etc/init.d/acpid restart
After the above, I am all set. When I am on battery power the “cpufreq-ondemand” governor will turn down my CPU clockrate when I am not using the processor much (which is quite often for most of us). When demand goes up, the clockrate goes back to the maximum to get the job done as fast as possible.
In addition to controlling the CPU frequency, the disk buffers are increased so hopefully the hard disk can be spun down more frequently and stay off for a while. There are more tricks you can use (such as changing the syslog so it won’t sync on each write). If you are not using your wireless, it is a good idea to have that off. So far, the only way I seem to be able to control that is to unload the module on my IBM T42. Also, dimming the screen as much as possible does seem to make some difference.
I have yet to do serious testing, but previously I was lucky to get an hour of battery life (using wifi), now it seems I can around 1.5 hours with the above. Of course, one problem could be that my battery is two years old and no longer holds a good charge:
bash# grep capacity /proc/acpi/battery/BAT0/info
design capacity: 47520 mWh
last full capacity: 25950 mWh
I am optimistic that something like Gnome Power Manager will make all this transparant to the user.
Note that Gentoo’s Power Management Guide is a useful resource.