If you’ve installed Asterisk 1.8 from Debian repository and do not have app_meetme, install the asterisk-dahdi package.
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Asterisk 1.8, Debian package, no app_meetme.so
Thursday, May 30th, 2013Switching from analog telephony to IP
Friday, May 24th, 2013Few days ago we successfully implemented the switching from analog to IP telephony in one company, the name of which we keep in secret due to the privacy policy.
The ‘uplink’ still remains analog, consisting of 15 PSTN lines (the client’s requirement). All 40 office phones now are SIP ones.
Eltex TAU-32M.IP VoIP gateway was used in conjunction with AsteriskNOW (client’s requirement, they wanted to have some web-interface at least to look for the system, what is happening inside) on the HP ProLiant DL160 Gen8 server.
SIP phones are Fanvil C56, Gigaset C610A IP and top Digium’s model – D70.
Asterisk: contactpermit and contactdeny
Thursday, May 23rd, 2013We can control in the [general] section of the sip.conf from which IP-addresses the device can register against our Asterisk server. This could be achieved with the ‘contactpermit‘ and ‘contactdeny‘ parameters:
contactdeny=0.0.0.0/0.0.0.0
contactpermit=10.145.13.0/255.255.255.0
contactpermit=10.145.14.0/255.255.255.0
The example above denies to register from any IP address and allows registration for devices which have 10.145.13.x or 10.145.14.x address.
Note, that these are separate options, besides ‘deny=x.x.x.x/x.x.x.x’ and ‘permit=x.x.x.x/x.x.x.x’, which are set in your SIP peers sections.
Sarg on CentOS 6.3
Tuesday, April 30th, 2013I never used CentOS before. That’s why this
note may be helpful for me in future.
Add the RepoForge repository to your CentOS system: http://repoforge.org/use/
Edit ‘/etc/yum.repos.d/rpmforge.repo‘ by changing ‘enabled = 0‘ to ‘enabled = 1‘ in second and third sections – in [rpmforge-extras] and [rpmforge-testing] respectively.
Update the yum repository cache.
Install sarg.
If you’ll get an error ‘SARG: (grepday) Fontname /usr/share/sarg/fonts/DejaVuSans.ttf not found‘ and there is no file DejaVuSans.ttf on your file system at all, download it and put somewhere, and add the according line in sarg.conf.
Without this error fixed, sarg will not generate the main index.html file, even if you commented out any options concernng graphs creating (‘graph_font /usr/share/fonts/DejaVuSans.ttf‘ and ‘graphs no‘). That is why it’s so important.
Asterisk & IPtables
Tuesday, January 22nd, 2013A good starting place is a set of rules similar to this one:
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -p tcp --dport 22 -j ACCEPT
iptables -A INPUT -p udp --dport 5060 -j ACCEPT
iptables -A INPUT -p udp --dport 10000:20000 -j ACCEPT
iptables -A INPUT -i lo -j ACCEPT
iptables -P FORWARD DROP
iptables -P OUTPUT ACCEPT
iptables -P INPUT DROP
Asterisk modules
Tuesday, January 22nd, 2013My practice of manual loading of needed modules only.
Change ‘autoload=yes‘ to ‘autoload=no‘ in /etc/asterisk/modules.conf .
Restart Asterisk – Asterisk CLI> core restart now (remember that it will cancel all active calls).
Login into Asterisk console (root# asterisk -rvvvvvvv). Then load modules manually:
Asterisk CLI> module load app_dial.so
Asterisk CLI> module load app_playback.so
Asterisk CLI> module load chan_sip.so
Asterisk CLI> module load codec_alaw.so
Asterisk CLI> module load codec_gsm.so
Asterisk CLI> module load res_rtp_asterisk.so
Asterisk CLI> module load res_musiconhold.so
Asterisk CLI> module load func_dialplan.so
Asterisk CLI> module load pbx_config.so
Asterisk CLI> module load format_sln.so
Asterisk CLI> module load format_wav.so
Asterisk CLI> module load format_gsm.so
Asterisk CLI> module load app_record.so
A nice help for modules being used is ‘Asterisk CLI> module show‘ . This is mine:
Asterisk CLI> module show Module Description Use Count res_musiconhold.so Music On Hold Resource 0 app_dial.so Dialing Application 0 app_playback.so Sound File Playback Application 0 chan_sip.so Session Initiation Protocol (SIP) 0 codec_alaw.so A-law Coder/Decoder 0 codec_gsm.so GSM Coder/Decoder 0 res_rtp_asterisk.so Asterisk RTP Stack 0 func_dialplan.so Dialplan Context/Extension/Priority Chec 0 pbx_config.so Text Extension Configuration 0 format_sln.so Raw Signed Linear Audio support (SLN) 0 app_record.so Trivial Record Application 0 format_wav.so Microsoft WAV/WAV16 format (8kHz/16kHz S 0 format_gsm.so Raw GSM data 0 13 modules loaded Asterisk CLI>
If you need AEL, you have to load 2 modules (in shown sequence):
Asterisk CLI> module load res_ael_share.so
Asterisk CLI> module load pbx_ael.so
The best practice is to configure /etc/asterisk/modules.conf according to its syntax, to prevent manual loading of modules each time your Asterisk PBX starts.
Your installation may need other modules as well.
Show txt file without comments and empty lines
Sunday, January 20th, 2013The command is grep -vE '^#|^;|^$' /etc/openvpn/client.conf
This is the output:
client
dev tun
proto udp
remote 10.11.12.13 1194
topology subnet
nobind
persist-key
persist-tun
ca /etc/openvpn/ca.crt
cert /etc/openvpn/client3.crt
key /etc/openvpn/client3.key
comp-lzo
verb 3
Printers control from the console
Saturday, January 19th, 2013A short list of helpful commands for printers’ control.
lpq – shows the default system printer (if set) and its printing queue;
lpstat -a – shows all printers, available in the system, their ‘working since’ time and type of connection (USB/local network, etc);
lpstat -p – shows all printers, available in the system, their ‘working since’ time and type of connection (USB/local network, etc);
lpstat -v – shows all printers, available in the system, their ‘working since’ time and type of connection (USB/local network, etc);
lpadmin -d printer_name – set the printer_name as default system printer;
lpadmin -x printer_name – deletes printer_name printer from the system;
cupsenable printer_name – turns the printer_name printer on on the OS level;
cupsdisable printer_name – turns the printer_name printer off;
cupsctl --share-printers – shares all printers in the system, making them available across the network; and run the next command =>
cupsctl 'BrowseLocalProtocols="all"' – use all protocols of network printing. If you use Linux machines only (both printing server and client), it’s better to type “ipp” instead of “all”. IPP means Internet Printing Protocol.
Shaping in Slackware
Thursday, January 17th, 2013An ‘iproute2’ package (description) must be installed. Let’s imagine that we use a default kernel in which ‘everything is included but the kitchen sink’. :)
FIRST. Create /etc/rc.d/rc.shaper with the following code:
#!/bin/bash
shaper_start() {
tc qdisc add dev eth1 root handle 1:0 htb default 254
tc class add dev eth1 parent 1:0 classid 1:1 htb rate 0.5mbit
tc class add dev eth1 parent 1:0 classid 1:2 htb rate 3.3mbit
tc class add dev eth1 parent 1:0 classid 1:254 htb rate 256kbit
tc filter add dev eth1 protocol ip parent 1:0 prio 1 u32 match ip dst 192.168.0.2 flowid 1:1
tc filter add dev eth1 protocol ip parent 1:0 prio 1 u32 match ip dst 192.168.0.3 flowid 1:2
}
shaper_stop() {
tc qdisc del dev eth1 root
}
shaper_restart() {
shaper_stop
sleep 1
shaper_start
}
case "$1" in
'start')
shaper_start
;;
'stop')
shaper_stop
;;
'restart')
shaper_restart
;;
*)
echo "usage $0 start|stop|restart"
SECOND. Make it executable: chmod +x /etc/rc.d/rc.shaper
THIRD. Add to /etc/rc.d/rc.inet2 these lines:
if [ -x /etc/rc.d/rc.shaper ]; then
/etc/rc.d/rc.shaper start
fi
Now type /etc/rc.d/rc.shaper start. After that your client with 192.168.0.2 IP address will have a 0.5 mbit/s bandwidth and 192.168.0.3 one will have 3.3 mbit/s. Any other IPs will have 256 kbit/s only, as it is set in the default shaping rule.
PostgreSQL Database Backup
Wednesday, January 16th, 2013For a single database mybase located on a server dbserver.local, from a user john :
pg_dump -h dbserver.local -U john mybase > backup_db_mybase.`date +%Y.%m.%d`.sql
This simple trick may do a great deal for you.