Reinstall or Upgrade the Dahdi driver to Latest version

Uninstall all the dahdi modules installed

Login to Server via ssh  (putty)

First check the dahdi modules installed by running below command

lsmod | grep dahdi

Now  uninstall all the modules listed by above command

modprobe -r wctc4xxp wctdm24xxp wcte12xp xpp dahdi_transcode wcb4xxp

modprobe -r wctdm wcfxo wctdm24xxp wcte11xp wct1xxp wcte12xp

modprobe -r dahdi_voicebus wct4xxp wctdm24xxp dahdi

Note: if you get error “FATAL: Module dahdi is in use.”

Stop dahdi by running “/etc/init.d/dahdi stop ”  and then run the above Commands

Downloading and installing Dahdi latest version.

# wget http://downloads.asterisk.org/pub/telephony/dahdi-linux-complete/dahdi-linux-complete-current.tar.gz

 #tar -xvzf dahdi-linux-complete-current.tar.gz

#cd dahdi-linux-complete-2.6.2+2.6.2

#make clean

#make all

#make install

#make config

Dahdi installation completed , run the below command if you have any digium cards or need to load dahdi dummy driver

#dahdi_genconf

#dahdi_cfg -vvv    ;to confirm dahdi works properly