Apr 22, 2012

DTMF Issue With Asterisk - Solution.

Asterisk is nothing but a Software implementation of Private Branch Exchange. Mark Spencer of Digium  has wrote this application once he is not able to find a PBX for his company. Now this application is using by lot of people for medium , and large scale enterprises.


The signals from a DTMF system is not recognised by the Asterisk. Specifically key press from Smart phones and Mobile phones who is sending DTMF signals.


You have a working Asterisk system

Add the following line in chan-dahdi.conf file


Save and Exit.

Reload the Asterisk.

Now you will be able to receive the Signals from DTMF devices.

VLAN With Hypervisor - KVM


Some times we need a VLAN inside the Linux machine to communicate with outside network. Specifically when we are dealing with Blade Servers. KVM Hypervisor only allows outside traffic through this VLAN only OR Management IP. We are not considering management NIC here.

The traffic from BladeS erver is allowed to main switch only through this VLAN. When a packet come from the Blade , the particular port of the switch will ask challenge to the packet for VLAN information. So we need to create a separate VLAN inside the Linux machine.


cp /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-eth0.300

vi /etc/sysconfig/network-scripts/ifcfg-eth0.300

Find the Word DEVICE and change its name to eth0.300 (Normally that should be eth0)

Add the Line       VLAN=yes

Restart the Network    /etc/init.d/network restart.

Adding a new VLAN

vconfig add eth0 5

Assigning an IPAddress to the VLAN

ifconfig eth0.5 netmask broadcast up

For Shutting down a VLAN

ifdown eth0.300

For Remove a VLAN

vconfig rem eth0.300