1. Login as user root;
2. Download file tzdata<year>l.tar.gz from ftp://elsie.nci.nih.gov/pub/ or some other tzdata provider:

#wget ftp://elsie.nci.nih.gov/pub/tzdata2010k.tar.gz

3. Extract timezone info file “africa” from the tarball using following command:

#tar -zxf tzdata2010k.tar.gz

#cd tzdata2010k

4. Modify file “africa” or some other zone by using your favorite text editor (vi, nano or something else):

#vi africa

(I have changed it to reflect my needs / EEST will change to EET on Aug 11, 5.00 AM)

5. Depending on your operating system, place file in one of the following directories:

/usr/share/lib/zoneinfo/src – Solaris
/usr/share/zoneinfo/src     – Linux

#mv africa /usr/share/lib/zoneinfo/src

#mv africa /usr/share/zoneinfo/src

6. Navigate to “src” directory and compile a new timezone data file using command “zic”

#cd /usr/share/zoneinfo/src

#zic africa

7. Copy newly generated file

 #cd .. && cp Africa/Cairo Egypt

8. Last step would be to test DST settings with following command:

#zdump -v Egypt | grep 2010

You should be able output similar to this, depending on what you have configured:

#zdump -v Egypt | grep 2010
Egypt Wed Aug 11 09:34:23 2010 UTC = Wed Aug 11 11:34:23 2010 EET isdst=0
Egypt Thu Apr 29 21:59:59 2010 UTC = Thu Apr 29 23:59:59 2010 EET isdst=0
Egypt Thu Apr 29 22:00:00 2010 UTC = Fri Apr 30 01:00:00 2010 EEST isdst=1
Egypt Wed Aug 11 01:59:59 2010 UTC = Wed Aug 11 04:59:59 2010 EEST isdst=1
Egypt Wed Aug 11 02:00:00 2010 UTC = Wed Aug 11 04:00:00 2010 EET isdst=0
Egypt Wed Sep 8 21:59:59 2010 UTC = Wed Sep 8 23:59:59 2010 EET isdst=0
Egypt Wed Sep 8 22:00:00 2010 UTC = Thu Sep 9 01:00:00 2010 EEST isdst=1
Egypt Thu Sep 30 20:59:59 2010 UTC = Thu Sep 30 23:59:59 2010 EEST isdst=1
Egypt Thu Sep 30 21:00:00 2010 UTC = Thu Sep 30 23:00:00 2010 EET isdst=0

That it is it! As you can se from above output time will automatically change on 5.00AM EEST and it will go one hour back to 4.00AM EET. I hope that this blog post clarify this procedure.

1. zic
2. zdump

Few days ago I moved my Ubuntu on laptop to version 10.04 and so far I am very satisfied with how does it work. That was a clear sign to refresh some software installs that I have and that fact included VMware server. Basically, I found VMware to suit my needs when it comes to personal virtualization. I am using virtualized CallManager (it is only supported with VMware) and also my appliance Linux environment is virtualized as well. There are other virtualisation solutions that I like but I will leave that for some other blog post.

So, I installed VMware Server 2.0.2 and it is working really nice. There are plenty of instruction manuals on VMware installation on Linux and Ubuntu, but I found this one to work like a charm. Under Ubuntu, I am using current version of Firefox, which is 3.6.3 and it seems to have a problem with VMware Remote Console Plug-in. It is not working at all. There is lot of discussion about this but I didn’t find that much solutions. Some are saying that some Firefox add-on for flash blocking is causing this to happen, but using Firefox without .mozilla didn’t help.

So, here is solution that actually works: Open Terminal and navigate to directory:

root@gomez-laptop:/# cd /usr/lib/vmware/webAccess/tomcat/apache-tomcat-6.0.16/webapps/ui/plugin/

once there, execute list command and you should be able to see vmware-vmrc-linux-x86.xpi file which is required:

root@gomez-laptop:/usr/lib/vmware/webAccess/tomcat/apache-tomcat-6.0.16/webapps/ui/plugin# ls
build_doNotErase.txt  vmware-vmrc-linux-x64.xpi  vmware-vmrc-linux-x86.xpi vmware-vmrc-win32-x86.exe  vmware-vmrc-win32-x86.xpi

Once, there, we need to unzip that file by issuing following command:

root@gomez-laptop:# unzip vmware-vmrc-linux-x86.xpi

and then, navigate to plugins directory and list the content:

root@gomez-laptop:/usr/lib/vmware/webAccess/tomcat/apache-tomcat-6.0.16/webapps/ui/plugin# cd plugins/
root@gomez-laptop:/usr/lib/vmware/webAccess/tomcat/apache-tomcat-6.0.16/webapps/ui/plugin/plugins# ls
bin  libconf                         open_source_licenses.txt  vmware-desktop-entry-creator  vmware-vmrc-daemon  xkeymap
lib  np-vmware-vmrc-2.5.0-122581.so  share                     vmware-vmrc vmware-vmrc-legacy
root@gomez-laptop:/usr/lib/vmware/webAccess/tomcat/apache-tomcat-6.0.16/webapps/ui/plugin/plugins#

And one last step is to start vmware-vmrc with following command:

root@gomez-laptop:/usr/lib/vmware/webAccess/tomcat/apache-tomcat-6.0.16/webapps/ui/plugin/plugins# ./vmware-vmrc -h localhost:8333

Please note that you can replace localhost with IP address of your working VMware server. Once above command is executed you need to authenticate and you should be able to select virtualized hosts. Please give a check to following screenshots:

As shown on above screenshot, we need to authenticate and one last step is to select one of the virtualized machines that we want to work with:

If there are some questions, please let me know. I hope that this workaround will save some time for you and that you will have working solution.

1. VMware server
2. VMware server installation on Ubuntu

Few days ago I had interesting request to tweak Linux on Samsung LCD TV. At first, I was kind of surprised that Linux is supported on TV, but it is normal. Linux is very strong competitor on the appliance based market and it was just about time to face those kind of installations. The main goal was to enable telnet on firmware in order to be able to connect to TV, and after that to load Common Internet File System to be able to use network mounts. Since I didn’t know anything about Samsung TV series and belonging firmware versions I needed to read something about that. Basically, there are differences in versions based on producing years and processors that are supported. This text is about to cover Samsung LCD TV LE40A756 and A856 with firmware T-RBYDEU. I need to mention that it is kind of easier to work with other models of Samsung LCD TVs since they seam to open more possibilities (this is just my opinion) for firmware hacking but this version was very interesting to play with as well. Since this firmware (as much as all other appliance based firmware versions) is using squash file system, to be able to add something on filesystem we would need to unsquash file system (unsquash is viable thru squashfs-tools) and then perform necessary changes. Since I am using Ubuntu which is providing newer version of squashfs-tools package than it is required (Ubuntu is providing squashfs-tools version 3.1 and it is required to have version 2.0) I didn’t follow that procedure. However, for those that would like to give it a try you can follow this procedure. We will follow other procedure.

Downloads

Navigate to Samsung web site > Support > Downloads > TV Audio Video > Choose a product type>: Television > Choose a product subtype: LCD TV > Select your TV model and then click on Select. You will be provided with the link to download your firmware version. In our case firmware is called T-RBYDEU.exe.

Firmware work

Using some of the decompression tools like 7zip, WinRAR or some other program that you use on the daily basis, we need to extract .exe file that we have downloaded. I will describe procedure under Linux operating system using 7zip:

7z x T-RBYDEU.exe

Once done, you will be able to see extracted files in directory T-RBYDEU. Please note that you will be able to see those files:

gomez@gomez-laptop:/media/Data_/T-RBYDEU$ ls -la
total 40
drwx—— 1 gomez gomez     0 2009-05-11 23:38 .
drwx—— 1 gomez gomez  4096 2010-04-01 16:22 ..
-rwxrwxrwx 1 gomez gomez 18929 2009-04-17 16:16 crc
drwx—— 1 gomez gomez  4096 2009-05-11 23:38 image
-rwxrwxrwx 2 gomez gomez  8676 2009-04-17 16:16 MicomCtrl
gomez@gomez-laptop:/media/Data_/T-RBYDEU$ cd image/
gomez@gomez-laptop:/media/Data_/T-RBYDEU/image$ ls -la
total 58166
drwx—— 1 gomez gomez     4096 2009-05-11 23:38 .
drwx—— 1 gomez gomez        0 2009-05-11 23:38 ..
-rwxrwxrwx 1 gomez gomez  8155136 2009-04-17 16:16 appdata.img
-rwxrwxrwx 1 gomez gomez   602112 2009-04-17 16:16 boot.img
-rwxrwxrwx 1 gomez gomez 37646336 2009-04-17 16:16 exe.img
-rwxrwxrwx 1 gomez gomez   177920 2009-04-17 16:16 fnw.bin
-rwxrwxrwx 1 gomez gomez       17 2009-04-17 16:16 info.txt
-rwxrwxrwx 1 gomez gomez    99680 2009-04-17 16:16 oneboot.bin
-rwxrwxrwx 1 gomez gomez  3424256 2009-04-17 16:16 rootfs.img
-rwxrwxrwx 2 gomez gomez  3172612 2009-04-17 16:16 T-RBYDAUM
-rwxrwxrwx 2 gomez gomez  3172612 2009-04-17 16:16 T-RBYDEUM
-rwxrwxrwx 1 gomez gomez   228296 2009-04-17 16:16 u-boot.bin
-rwxrwxrwx 2 gomez gomez       47 2009-04-17 16:16 validinfo.txt
-rwxrwxrwx 2 gomez gomez       43 2009-04-17 16:16 version_info.txt
-rwxrwxrwx 1 gomez gomez  2864533 2009-04-17 16:16 vmlinux.ub
gomez@gomez-laptop:/media/Data_/T-RBYDEU/image$

As per above output, please note that we have directory called image, and from the interesting files we have exe.img and validinfo.txt which will be used in following text.

Firmware tweaks

Next thing that we need to do is to prepare exe.img for additional changes in order to be able to telnet to TV and use some networking services like CIFS. Now, navigate to image directory and create directory temp:

gomez@gomez-laptop:/media/Data_/T-RBYDEU$ cd image/
gomez@gomez-laptop:/media/Data_/T-RBYDEU/image$ mkdir temp
gomez@gomez-laptop:/media/Data_/T-RBYDEU/image$

Once done, we will mount exe.img with the type of vfat to newly created temp directory:

gomez@gomez-laptop:/media/Data_/T-RBYDEU/image$ sudo mount -t vfat -o loop exe.img temp/

With above command, we have mounted exe.img to temp directory. Please note that we have following files inside temp directory:

gomez@gomez-laptop:/media/Data_/T-RBYDEU/image$ cd temp/
gomez@gomez-laptop:/media/Data_/T-RBYDEU/image/temp$ ls -la
total 28980
drwxr-xr-x 3 root root 16384 1970-01-01 01:00 .
drwx—— 1 gomez gomez 4096 2010-04-04 19:06 ..
-rwxr-xr-x 1 root root 29487160 2009-04-17 16:16 exeDSP
drwxr-xr-x 3 root root 8192 2009-04-17 16:16 modules
-r-xr-xr-x 1 root root 131072 2009-04-17 16:16 $rfs_log.lo$
-r-xr-xr-x 1 root root 8192 2009-04-17 16:16 rfs_pool.sy$
-rwxr-xr-x 1 root root 4374 2009-04-17 16:16 run
-rwxr-xr-x 1 root root 4525 2009-04-17 16:16 start.sh
gomez@gomez-laptop:/media/Data_/T-RBYDEU/image/temp$

Please note that we have start.sh file which we will use in following text.

Scripts

Using your favourite text editor, replace current start.sh file with following:

#!/bin/sh

if [ -e /mtd_chmap/start.sh ]
then
echo “user start.sh found!”
/mtd_chmap/start.sh
else

export PATH=/sbin:/usr/sbin:/usr/bin:/bin:/usr/local/bin:/usr/local/sbin
#export LD_LIBRARY_PATH=/usr/local/lib:/usr/lib:/lib
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/mtd_cmmlib:/usr/local/lib:/usr/lib:/lib
export HOME=/tmp/root
export TERM=linux
export LOGNAME=”root”
cd /dtv/usb
PU=`cat log | grep Mount`
PU=`echo ${PU##MountDir : }`
echo $PU
$PU/usb.sh &

mount

## mount -n -t usbfs none /proc/bus/usb

ulimit -s 2048

export PS1=’\h:\w\$ ‘

## STAPI Root Device Name?## ———————-
ST_DEV_ROOT_NAME=stapi
export ST_DEV_ROOT_NAME

## STAVMEM Device Name
## ——————-
STAVMEM_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stavmem_ioctl
export STAVMEM_IOCTL_DEV_PATH

## STAUDLX Device Name
## ——————-
STAUDLX_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/staudlx_ioctl
export STAUDLX_IOCTL_DEV_PATH

## STBLAST Device Name
## ——————-
STBLAST_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stblast_ioctl
export STBLAST_IOCTL_DEV_PATH

## STBLIT Device Name
## ——————
STBLIT_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stblit_ioctl
export STBLIT_IOCTL_DEV_PATH

## STCC Device Name
## —————-
STCC_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stcc_ioctl
export STCC_IOCTL_DEV_PATH

## STCLKRV Device Name
## ——————-
STCLKRV_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stclkrv_ioctl
export STCLKRV_IOCTL_DEV_PATH

## STDENC Device Name
## ——————
STDENC_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stdenc_ioctl
export STDENC_IOCTL_DEV_PATH

## STEVT Device Name
## —————–
STEVT_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stevt_ioctl
export STEVT_IOCTL_DEV_PATH

## STFASTFILTER Device Name
## ————————
STFASTFILTER_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stfastfilter_ioctl
export STFASTFILTER_IOCTL_DEV_PATH

## STFDMA Device Name
## ——————
STFDMA_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stfdma_ioctl
export STFDMA_IOCTL_DEV_PATH

## STGFB Device Name
## —————–
STGFB_CORE_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stgfb_core
export STGFB_CORE_DEV_PATH
STGFB_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stgfb_ioctl
export STGFB_IOCTL_DEV_PATH

## STHDMI Device Name
## ——————
STHDMI_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/sthdmi_ioctl
export STHDMI_IOCTL_DEV_PATH

## STI2C Device Name
## —————–
STI2C_IOCTL_DEV_PATH=”/dev/${ST_DEV_ROOT_NAME}/sti2c_ioctl”
export STI2C_IOCTL_DEV_PATH

## STLAYER Device Name
## ——————-
STLAYER_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stlayer_ioctl
export STLAYER_IOCTL_DEV_PATH

## STMERGE Device Name
## ——————-
STMERGE_IOCTL_DEV_PATH=”/dev/${ST_DEV_ROOT_NAME}/stmerge_ioctl”
export STMERGE_IOCTL_DEV_PATH

## STPIO Device Name
## —————–
STPIO_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stpio_ioctl
export STPIO_IOCTL_DEV_PATH

## STPTI4 Device Name
## ——————
STPTI4_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stpti4_ioctl
export STPTI4_IOCTL_DEV_PATH

## STSMART Device Name
## ——————-
STSMART_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stsmart_ioctl
export STSMART_IOCTL_DEV_PATH

## STSYS Device Name
## —————–
STSYS_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stsys_ioctl
export STSYS_IOCTL_DEV_PATH

## STTTX Device Name
## —————–
STTTX_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stttx_ioctl
export STTTX_IOCTL_DEV_PATH

## STTUNER Device Name
## ——————-
STTUNER_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/sttuner_ioctl
export STTUNER_DEV_PATH

## STVBI Device Name
## —————–
STVBI_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stvbi_ioctl
export STVBI_IOCTL_DEV_PATH

## STVID Device Name
## —————–
STVID_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stvid_ioctl
export STVID_IOCTL_DEV_PATH

## STVIN Device Name
## —————–
STVIN_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stvin_ioctl
export STVIN_IOCTL_DEV_PATH

## STVMIX Device Name
## ——————
STVMIX_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stvmix_ioctl
export STVMIX_IOCTL_DEV_PATH

## STVOUT Device Name
## ——————
STVOUT_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stvout_ioctl
export STVOUT_IOCTL_DEV_PATH

## STVTG Device Name
## —————–
STVTG_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/stvtg_ioctl
export STVTG_IOCTL_DEV_PATH

STTKDMA_IOCTL_DEV_PATH=/dev/${ST_DEV_ROOT_NAME}/sttkdma_ioctl
export STTKDMA_IOCTL_DEV_PATH

RUN=1
/exe/exeDSP

Please note bold lines. Basically, it is the same file except that we are instructing our Linux firmware to load usb.sh script which needs to be located on USB root directory. usb.sh script will instruct Linux firmware to start busybox instance of telnet deamon so that we are able to telnet to our TV, and additionally it will load cifs.ko kernel module which will enable Common Internet File System so that we are able to mount some network devices on our Linux firmware. usb.sh script looks like:

#! /bin/sh

echo “!!!!!!!!!!!!!! USB START !!!!!!!!!!!!!!”

/bin/stty -F /dev/ttyAS0 ospeed 57600 ispeed 57600
#line before enables console for speed 57600. Put ‘debug’ to console and you see menu, put ’12′ and ENTER
echo “!!!!!!!!!!!!!! start console on 57600 !!!!!!!!!!!!!!”

#sleep 25 sec is need for wait ethernet start
sleep 25

cd /dtv/usb
PU=`cat log | grep Mount`
PU=`echo ${PU##MountDir : }`

echo “!!!!!!!!!!!!!! start telnet !!!!!!!!!!!!!!”
$PU/busybox telnetd -l /bin/sh

echo “!!!!!!!!!!!!!! start cifs.ko !!!!!!!!!!!!!!”
cd $PU
insmod cifs.ko

sleep 4

echo “!!!!!!!!!!!!!! clear old contents USB on TV !!!!!!!!!!!!!!”
rm /mtd_contents/V* -R
rm /mtd_contents/database -R

echo “!!!!!!!!!!!!!! start mount !!!!!!!!!!!!!!”
mount -t cifs //192.168.0.1/photo $PU/photo -o user=user_xp -o pass=password_xp
mount -t cifs //192.168.0.1/mp3 $PU/mp3 -o user=user_xp -o pass=password_xp
mount -t cifs //192.168.0.1/video $PU/video -o user=user_xp -o pass=password_xp

mount

echo “!!!!!!!!!!!!!! USB END !!!!!!!!!!!!!!”

Please note bold lines. Basically, we are starting telnet daemon and loading cifs.ko kernel module. After that, we are mounting some Windows XP shares from our personal computer which is working on 192.168.0.1 IP address. Once this file is loaded, and those mount locations are created you will be able to use files within above directories on your TV from the TV menus.

Please note that usb.sh, cifs.ko, busybox files and mp3, video, and photo directories needs to be located on USB root location.

Once done with that, we are ready to preform final changes to our firmware. First thing that we need to do is to umount temp directory:

gomez@gomez-laptop:/media/Data_/T-RBYDEU$ sudo umount /home/gomez/Desktop/T-RBYDEU/temp

Then, we need to delete temp directory:

gomez@gomez-laptop:/media/Data_/T-RBYDEU/image$ sudo rm -rf temp/

Once done with that, we need to change CRC information, because we have changed exe.img file. We can do that as follows:

gomez@gomez-laptop:/media/Data_/T-RBYDEU/image$ crc32 exe.img
cdc8080c

Once we have CRC information, we need to enter new value to validinfo.txt file:

gomez@gomez-laptop:/media/Data_/T-RBYDEU/image$ cat validinfo.txt
*007_exe.img_663430d9*011_appdata.img_a485b538

Please note value 663430d9. We need to change that value with cdc8080c that we have got as output from crc32 command. You can do that by using your favourite text editor. Once done with that, we are done with tweaking our Linux firmware. Your USB pen content should look like this:

gomez@gomez-laptop:~/Desktop/USB$ ls -la
total 3644
drwxr-xr-x 6 gomez gomez    4096 2010-04-05 08:59 .
drwx—— 8 gomez gomez    4096 2010-04-05 09:03 ..
-rwxrwxrwx 1 gomez gomez  992084 2009-11-18 23:13 busybox
-rwxrwxrwx 1 gomez gomez 2707316 2009-11-17 20:08 cifs.ko
drwx—— 2 gomez gomez    4096 2009-12-28 09:12 mp3
drwx—— 2 gomez gomez    4096 2009-12-28 09:12 photo
drwx—— 3 gomez gomez    4096 2010-04-05 08:59 T-RBYDEU
-rwxrwxrwx 1 gomez gomez    1026 2009-12-28 09:14 usb.sh
drwx—— 2 gomez gomez    4096 2009-12-28 09:12 video

If that is the case, you can put this USB to your TV, turn it on and you will be prompted to upgrade firmware with firmware version listed on your USB pen. Once you perform this upgrade, you will be able to telnet to your TV. Check your TV IP address from TV menus, and then using Linux shell, or if you are Windows user using Putty, telnet to your TV and enjoy power of your Linux shell. Also, using TV menus and Common Internet File System – CIFS, you can play some music, video or photos on your TV (as described above).

If you are lazy to give a check to this procedure, you can download fully operational USB image on this link. You are doing that on your own risk and author of this blog post is not responsible for any damage that you might cause by some operation.

Enjoy power of Linux shell on your Samsung TV!

For more information please visit following links:

1. SamyGo wiki pages
2. How to enable Telnet on Samsung TV’s
3. Hacking T-RBYDEUC Firmware – LE40A756 and A856

Few days ago we finally got our new optical connection. It is working like a charm. Having optical connection and Cisco router from one side and Asterisk server from the other side was a clear sign that we could/should implement QoS for voice traffic. By default, Asterisk is using port range 10000 to 20000 for RTP streams (which is adjustable in /etc/asterisk/rtp.conf) so you have several solutions how to implement Low Latency Queuing – LLQ on Cisco router. You can:

1. use Network Based Application Recognition NBAR to recognize your RTP traffic by using command ‘match protocol rtp’ within required class map;
2. create access control list which would comprehend all the traffic which is working as UDP in port range 10000 to 20000 by executing command ‘access-list 101 permit udp any range 10000 20000 any’ and then call that access control list within class map by using command ‘match access-group 101′;
3. make your Asterisk mark your SIP or RTP traffic by default.

From above listed solutions to this problem, third solution was most logical to me, although all solutions would work. Since there is recommendation to mark traffic as close to source as possible third option was very logical thing to go for. If you are using Asterisk which is working on Linux as root user (in most cases it is working with asterisk user by default) you will need to edit your sip.conf and within section [general] you will need to add following:

tos_sip=cs3
tos_audio=ef

Once done with that, save your configuration, reload asterisk and you are ready to go for Cisco configuration.

As I already mentioned, in most cases Asterisk is using user asterisk for the Asterisk daemon. If that is a case, above listed solution won’t work for you because Linux as operating system won’t allow you to mark your packages as non root user. That is very logical since we would be able to mark our web or some peer to peer traffic packages as EF (expedited forwarding) and obtain priority which is not desired at all. But, there is very powerful solution by using iptables. As root, you will need to execute following:

iptables -A OUTPUT -t mangle -p udp -m udp –dport 5060 -j DSCP –set-dscp 0×28
iptables -A OUTPUT -t mangle -p udp -m udp –sport 10000:20000 -j DSCP –set-dscp 0×28

By executing above commands you will mark your SIP and RTP traffic as DSCP CS5 (IP Precedence 5). You can verify that by catching a trace using snoop/tcpdump.

In case that you would like to set different DSCP values for some traffic, please find partial list here:
Expedited Forwarding, DSCP = 0x2E
CS5, DSCP = 0×28
CS6, DSCP = 0×30
CS7, DSCP = 0×38

Now last thing that we would need to do on the Linux side is to add those iptables rules to load on boot. Edit /etc/rc.local using your favorite text editor and paste above listed iptables lines and save it. Please note that rc.local file is loaded after the network, so if you are planning to put some firewall lines beside those that mark sip and trp traffic you might end up without your firewall rules for few seconds (otherwise, you can execute ‘iptables-save >/etc/iptables.rules‘ and then you would just need to add following line ‘pre-up iptables-restore < /etc/iptables.rules‘ to ‘/etc/network/interfaces‘ by using your favorite text editor to be loaded with network).

On the Cisco router side, we will configure Low Latency Queueing – LLQ to put some priority onto our CS5 marked packages. First thing that we need to do is to create class map from the global configuration mode by executing following commands:

router>enable
router#conf t
router(config)#class-map match-any voice
router(config-cmap)#match ip dscp cs5
router(config-cmap)#exit
router(config)#

By creating class map as listed above we would select our Asterisk marked cs5 packages. Next thing that we need to do is to define what we want to do with above selected cs5 marked packages. We are doing that by creating policy map as follows:

router(config)#policy-map llq
router(config-pmap)#class voice
router(config-pmap-c)#priority percent 20
router(config-pmap-c)#exit
router(config-pmap)#class class-default
router(config-pmap-c)#fair-queue

As per above configuration we are creating policy map called llq, and within that we are specifying 20 percent of available bandwidth for class voice. Please note that we need to have correct bandwidth statement under interface which is connected to WAN. Also, please note that we have enabled fair queueing on class-default (all data which is not selected by some other class map).

Last thing to do in regards to configuration is to enable policy map on interface which is facing connection towards your Internet Service Provider (WAN interface). We can do that by navigating to interface configuration mode and applying service policy in output direction as per following example:

router(config-pmap-c)#exit
router(config-pmap)#exit
router(config)#interface fastEthernet0/1
router(config-if)#service-policy output llq

And that is all. Now, we need to check results of our work by executing following command:

router#show policy-map interface fastEthernet 0/1
FastEthernet0/1

Service-policy output: llq

queue stats for all priority classes:
Queueing
queue limit 64 packets
(queue depth/total drops/no-buffer drops) 0/0/0
(pkts output/bytes output) 947031/193919404

Class-map: voice (match-any)
856803 packets, 170900643 bytes
1 minute offered rate 22000 bps, drop rate 0 bps
Match: ip dscp cs5 (40)
856803 packets, 170900643 bytes
1 minute rate 0 bps
Priority: 20% (400 kbps), burst bytes 15000, b/w exceed drops: 0

Class-map: class-default (match-any)
5321936 packets, 1534281066 bytes
1 minute offered rate 20000 bps, drop rate 0 bps
Match: any
Queueing
queue limit 64 packets
(queue depth/total drops/no-buffer drops/flowdrops) 0/0/0/0
(pkts output/bytes output) 5322316/1531545858
Fair-queue: per-flow queue limit 16

Please note packet counts under voice class on this policy. That means that we have deployed working configuration which will improve your voip experience. Your voip traffic will get priority among other aggressive traffic flows. Please find some additional information below, and feel free to contact me in order that you have additional questions.

1. Low Latency Queueing
2. Quality of Service

One of the biggest IT conferences, and most probably biggest GNU/Linux conference, Debconf (Debian Developers Conference) will take place in Banja Luka, Bosnia and Hercegovina in 2011! Among very professional bids from Munchen (Germany) and Quito (Equator), our Banja Luka bid won. Everything was carefully prepared and well organised by local team with Adnan Hodzic as lead person. We need to mention that we have full support which include funding, venues and else from Government of Republika Srpska which signed support letter (you can find it on Banja Luka bid wiki page). As the person which participated at Debconf7 in Edinburgh I am really happy that I will have opportunity to see known people, but also that Bosnia and Hercegovina will host this since this is our second bid (Sarajevo bid for dc7). It is our pleasure to have opportunity to host Debconf11 and we hope to see you here next year!

1. Banja Luka bid wiki page
2. My dc7 summary blog page

http://www.lpi.org/verify
LPI ID: LPI000116482
Code: uuw3rpvp8v

1. What is Linux Professional Institute?
2. Linux Professional Insitute Certifications

Now, before I start describing anything I need to say that I am using Ubuntu 9.04 on my laptop. Few of the reasons for using Ubuntu would be that it is working very nice, it is fast enough, it is nice looking and very stable at the same time, and at the end of day it is Debian based, and I proudly admit that I am emotional when it is about Debian. Ok, now back to VPN clients.

We are using IPsec. Therefore, I needed something that can support it and actually I have found two real possibilities:

1. Cisco VPN client for Linux
2. vpnc

I was working with vpnc before and I have to admit that it was my first selection. In my personal opinion it is working very nice, and it is really easy to use. network-manager-vpnc is actually just a vpnc plugin for network-manager and is nice solution because you will be able to use it from nm-applet from panel which is more friendly than connecting over console. vpnc is capable of working just over UDP and I have found it as huge limitation. I am working from the network which is reaching limits almost all the time, and UDP in those kind of networks is not that good solution. In most cases, if you are using UDP and you are working from those described networks you will see on the statistics that you are sending bytes, but you are not receiving anything. I was trying to find some vpnc clone that is working over TCP, because we obviously need some packet delivery guarantee, but I wasn’t that successful. That was reason to try Cisco VPN client.

There is really good project page for Cisco VPN client at this link. As i have heard, people were complaining that it is hard to compile it and install it, but with installations provided on the above link, it is not that hard to accomplish that. Main reason why em I actually using Cisco VPN client is ability to work over TCP. It is working really good, it is stable and I would, from my personal experience, recommend it.

I have noticed that huge disadvantage of using Cisco VPN client is using it over wireless network. After certain period of time my Ubuntu just freezes and only way to get it working is to turn it off, and start it over again. Solution is to use wired network, after that it is all work fine. It seems that Intel wireless driver is actually making this problem, but I was reading that some of the users are complaining on really bad multi core support. One of the solutions was to start it with just one core (which means to disable one core in prior to starting vpn client), which is not that user friendly. One of following posts will describe procedure how to install and to configure both vpnc and cisco vpn client, and how to resolve some of the issues that might occur while using them.

Obavještavamo sve zainteresovane da je objavljena finalna verzija Bosanskohercegovačkog Linux desktopa BHLD 2.0. Ovaj projekat je finansiralo Ministarstvo obrazovanja, nauke i kulture FBiH, a vodio ga je dr Samir Ribić sa ETFa Sarajevo. U projektu su učestvovali i mnogobrojni studenti ETFa (kojima se ovom prilikom zahvaljujemo).

Bh. Linux desktop je projekat čiji je cilj prezentovanje Linuxa u svojstvu radne stanice (desktopa) kao i aktivnosti ULK na lokalizaciji (prevođenu na naše jezike) grafičkog okruženja i aplikacija. BHLD 2.0 dolazi sa setom aplikacija posebno prilagođenim za primjenu u obrazovanju, kao i sa vrlo detaljnim priručnikom na našem jeziku u kojem su opisane sve aplikacije uključene u distribuciju. Od aplikacija ističemo OpenOffice.org 3.1 i Firefox 3.0. Pored standardnog KDE okruženja BHLD 2.0 sadrži i lagano okruženje za starije računare te bi trebao biti upotrebljiv i na računarima sa svega 128 MB RAM. BHLD je “live CD” što znači da ga možete isprobati bez instalacije, a za razliku od verzije 1.x instalacija na disk je potpuno podržana.

Verzija 2.0 bazirana je na megapopularnoj Ubuntu Linux distribuciji. Tehničke detalje (spisak paketa) možete saznati na ULK wiki stranici koja će se po potrebi dopunjavati informacijama:
http://wiki.linux.org.ba/BHLD2

BHLD 2.0 moći ćete naći u sljedećem broju magazina “Info” zajedno sa člankom i intervjuom, a ISO image možete preuzeti sa mirror servera:
ftp://mirror.bhld.com.ba/bhld/ (BH Telecom)
http://europronet.ba/bhld/ (Europronet – za korisnike cable zone: ftp://cableftp.europronet.ba/DOWNLOAD/OS/Linux/BHLD/)

Sva pitanja u vezi BHLDa i pomoć za korištenje možete dobiti na ULK forumu – sekcija BHLD koji redovno prati i sam dr Ribić (nick “megaribi”).

Pozivamo vas na promociju BHLD 2.0 koja će se održati u subotu 4. jula 2009. u 12:00 u Malom amfiteatru Elektrotehničkog fakulteta (ETF-MA):
* Mapa (koristite kontrolu sa lijeve strane da napravite zoom-in / zoom-out, ili vucite mišem mapu za skrolovanje)
Ovom prilikom ćete se moći učlaniti u Udruženje Linux korisnika, dobiti majice i kape sa logom Udruženja kao i odštampane BHLD priručnike sa CDom.

1. Udruženje Linux korisnika Bosne i Hercegovine
2. BHLD 2.0

Anketa se ne može uzeti kao definitivan pokazatelj iz mnogo razloga (čak šta više, bilo bi interesantno saznati ko ima službeno pravo da proglasi ovakve ankete realnim pokazateljima) međutim definitivno može da pokaže smjer kretanja pojedinih elemenata koji se direktno tiču FOSS community/a. Interesantno je to da je ove godine anketa zabilježila gotovo dvostruko više posjeta nego prošle godine.

U sljedećem tekstu probat ću da se osvrnem na rezultate:

Prema navedenoj statistici najveću zastupljenost kao i prošle godine ima Ubuntu Linux, što je bilo i za očekivati. Ubuntu je i na Distro watchu već dugo vremena zakovan na prvom mjestu i razvoj ovakve situacije je bio sasvim očekivan. SuSE na drugom mjestu očekivano, mada sam mislio da bi pozicija mogla biti dosta ugrožena od kategorije koja se nalazi pod ‘Other Debian’ (jer ima zaista veliki broj distribucija baziranih na istom). Ono što me iznenadilo na navedenom chart/u jeste veoma dobra pozicioniranost Gentoo Linux/a za kojeg nisam pretpostavljao da ovako visoko kotira.

Na području internet preglednika ništa se nije mijenjalo. Firefox je zadržao apsolutnu dominaciju nad Konquerorom i Operom i vjerujem da će se isti trend nastaviti duže vremena.

Ovaj me chart uvijek iznenadi pozitivno, iako su rezultati koji su navedeni sasvim očekivani. Ubuntu forsira GNOME, od verzije 10 SuSE Linux radi isto, tako da je GNOME dominacija očekivana. Bez obzira na sve, smatram da se KDE prema ovoj statistici veoma dobro drži što potvrđuje kvalitet istog.

Da kvalitetan proizvod sa jakim marketingom iza sebe može da promjeni i navike korisnika prema gore navedenom chart/u pokazuje Thunderbird. Iskreno sam se iznenadio kada sam vidio da ima prednost nad Evolution/om koji dolazi kao default emal klijent uz GNOME i Kmail/om koji je tu uz svaku instalaciju KDE/a.

Posebno interesantna mi je ova statistkika. Pored prilično kvalitetnih virtualizacijskih modela kao što je vserver, qemu ili neki drugi korisnici se okreću dobrom starom Wine/u. VMWare solidno kotira na ovoj ljestvici ali mislim da je Crossover podbacio iako se radi o dosta kvalitetnom proizvodu.

Sve u svemu, veoma interesantna godišnja statistika koja pokazuje da ukoliko se radi o kvalitetnom proizvodu sa jakim marketingom, ni lobi proizvođaća ili navike korisnika nisu prepreka u korištenju istih.

1. 2007 Desktop Linux Survey results revealed
2. Ubuntu Linux
3. Distro watch
4. SuSE Linux
5. Firefox
6. Thunderbird
7. Gentoo Linux
   
8. VMWare
9. Crossover office

Radi se o veoma dobroj mašini: Fujitsu Siemens TX200 S3. Mašina je opremljena sa dva Xeon procesora, dva gigabajta RAM/a, tri gigabitna ethernet/a, RAID kontrolorom i ostalom opremom sa kojom mašine tog tipa dolaze.

Izbor operativnog sistema sveo se na dvije moguće opcije: Gentoo i Debian. Kako sam projekat trebao da uradim u svoje slobodno vrijeme (dakle, poslije posla, a slobodnog vremena je uvijek malo), te sa obzirom na činjenicu da je kompajliranje spor i kompleksan posao Debian se učinio boljom solucijom i na mašini sve uskoro veselo vrtio Debian Etch. Dakle, Gentoo koji se veselo vrtio dvije godine (čini mi se) zamjenjen je Debianom.

40/ak gigabajta samba share/a se prebacivalo nekoliko sati sa starog servera koristeći rsync. U međuvremenu, prebacivano je desetak aktivnih domena sa svim sadržajima. To je naravno podrazumijevalo podešavanje baze, a za tu svrhu redovno koristim dobri stari mysql u posljednjoj stabilnoj verziji (iako planiram da polako sve prebacujem na PGSQL). Dok je rsync lijepo obavljao svoj dio posla, vrijeme je korišteno i za podešavanje DNS servera. Kako tu uvijek ima promjena od verzije do verzije, ovaj put bilo je problema sa MX exchangerima ali i to je relativno brzo riješeno.

Očekivano, najveći problem je predstavljala migracija mail servera. Nekoliko stotina account/a i nekoliko hiljada mailova u njima, kao i sve autentifikacijske postavke trebale su da budu prebaćene bez ikakvih problema. Radi kompatibilnosti koristio sam isti mail server, tako da sam nakon nekih manjih peripetija imamo POP3, IMAP, Spamassasin, CLAM antivirus i ostalo ureduno funkcionirajući.

Dakle, urađeno je prilicno dosta posla u relativno kratkom vremenskom periodu (nekih desetak dana posla, ali samo u slobodno vrijeme). Sa obzirom na činjenicu da tamo imaju ljude koji će održavati ovu instalaciju, moj posao na ovom projektu je završen na duge staze.

1. Fujitsu Siemens
2. Fujitsu Siemens TX200 S3
3. Univerzitet