26oct11

= 26 October 2011 LUG meeting notes =

We held our GNU/Linux User Group meeting last night 26-Oct-2011 after work (from 17:30 to 19:00).

Testing USB 3G modem with GNU/Linux
We started out by connecting my laptop at home (a Dell Studio 1537 with an Intel Core2duo P8400 cpu) to the internet via a used (and somewhat old) Huwaei K3520 3G USB modem (unlocked) that my wife purchased on ebay.de for 22 euros. My wife put a T-Mobile pay as you go sim card in it, and its use on GNU/Linux KDE is fairly simple. On openSUSE-11.3 with KDE4 one plugs in the modem to a USB port, knetworkmanager recognizes the modem, and one then selects the modem in knetworkmanger and one has Internet access. Thats all ! (I did need to install the rpm huawei_umtsmodem first, which has the UDEV rules so that the 3G USB modem is recognized when plugged in). The pay-as-you-go T-Mobile account (called 'Xtra Click' ) that my wife uses is very inexpensive, but also it is slow (it uses only a small fraction of this 3G modems speed capability). My wife paid 10 euros for the sim card, and that gives her 10 euros credit. When one connects to the Internet in Germany, one is automatically billed 0.99 euros and is given 24-hours access. The 'catch' is the download speed is only 384 kbit/sec download and 32 kbit/sec upload. If one uses over 200MBytes bandwidth in that 24 hours, then the download speed is throttled down to 64 kbit/sec and 16 kbit/sec upload. so clearly that is only good for email and surfing. But for .99 euros, pay-as-you go, we find it inexpensive. There are MUCH higher speed options available for much more money.

I'm told in France, if I use this same sim, I will be charged 1.99 euros for 24 hours. I have not confirmed that.

We used this 3G connection for most of the evening, when surfing for web sites to support our GNU/Linux discussions.

This Huwaei K3520 3G USB also will take a mini-sim card, and my wife put a 16GB mini-sim in it, such that this device now acts as a dual 3G modem and 16GB USB memory stick. Here is an image of this modem



Of interest is this device actually has an antenna that is functional, but not accessible, as it is deliberately blocked by the cover (as a Vodafone marketing decision) ... I have read that if one opens the case it looks like this:



And to put that in perspective with the case on ...



Ergo one could drill a hole in the side of the case to create an entry hole for an antenna to connect. 

The IP address using this 3G modem/sim combination was a bit bizarre, as it appears to use a local LAN designated IP address (that starts with a 10.x.x.x) although when one checks a website for their IP-address, one will see a different IP that the ISP has assigned (85.x.x.x in the case of last night).

Networking (proxy)
We also spent a LOT of time chatting a lot about networking, although most of the tunnelling and apache explanations went far over my head. ... We talked about the application 'proxytunnel' and discussed the use of two of the common PC ports.

The chat about ports and connections mentioned also the possibilities to access one external machine HTTPS and SSH protocol (for remote terminal usage) on the same port. As an alternative, the only HTTPS connection would allow also terminal usage with the software Ajaxterm Installed on the target machine.

Perhaps, the remote access mechanisms and features can be the topic of a future meeting.

Mobile Portable Wireless Router
I did note my wife and I plan to buy a mobile wireless router (possibly a Edimax 3G Wifi 6218n router which is the size of a blackberry phone, and has 2 USB ports: one normal size and one mini where the normal size is for a USB 3G modem to plug in, and the mini is for a power adaptor (and can also be plugged into a computer to get power from the computer)). That Edimax mobile router also has a battery. Why buy a mobile router ? The concept is if the family is travelling and waiting in a train station, or hotel with no internet, one can obtain Internet via this mobile router and broadcast their own very short range mini-WLAN and both husband, wife (and other family members) can all access the internet simultaneous with their separate laptops, tablets, iPod/iPad, etc .. and not need a 3G modem in each device.

Wireless Access Point
Eugenio also noted another solution would be to have one's laptop configured as a wireless access point. We did not discuss the that setup.

GNU/Linux Pulse Audio Volume Control Application
And on the old EUMETSAT GNU/Linux User Group laptop (which is running openSUSE Tumbleweed-11.4 (a rolling release with a 3.0 kernel )) we looked briefly at the pulse audio volume control application pavucontrol (which has come a long ways since the previous days where pulse audio was unstable). With this 'rolling release' there is a fairly stable version of pulse audio on this laptop. We demonstrated playing audio from smplayer and youtube at the same time, with separate volume controls for each.

I did not make screen dumps of them from last night, but below are some examples (from my PC at home) as to what this might look like. For example, on my Asus P6T Deluxe V2 motherboard, where I have a Logitech webcam attached (the webcam has a mic) I see this in the Configuration tab of the application ‘pavucontrol’ (with the motherboard device on top and webcam on the bottom):



Now on the Asus P6T Deluxe V2 motherboard configuration control in pavucontrol there are many options:



The output tab on the same PC, in pavucontrol looks like this with the various speaker controls available:



And finally here is an example of pavucontrol at work where the PC is playing back audio from smplayer (in the middle) and playing back flash audio from youtube (on the bottom) with a firefox browser plugin at the same time as smplayer playing, with separate volume controls for each. Note system sounds volume control is on top:



Now NOT shown is what this would look like if one had multiple sound devices on this PC. If one had multiple sound devices there would be a drop down menu associated with each media playback in that playback tab, and one would be able to select for each application the output device (speakers) that it sends its audio to. For example, with pulse audio one can play media-file-A with application-X and send it speaker-system-1, and play media-file-B with application-Y and send it to a different speaker-system-2, each with their own volume controls. And its easy to do because the GUI is fairly basic. ... or with an edit of a configuration file, one can mix the two, and play media-file-A with application-X and send it to both speaker-system-1 and speaker-system-2.

The same applies with recording. If one has more than one sound device mic, one can take the input of one mic (say #1) and send it to record application-A,and one can the input of another mic (say #2) and send it to record application-B, ALL at the same time.

For those of us who like to play with multimedia but we do not have the time to learn 'jack' (where ‘jack’ is more capable) this is a very easy way to obtain some flexible sound capabilities.