I went to the host system
[root@OpenVZ zaptel-1.2.1]# /etc/rc.d/init.d/zaptel start
Loading zaptel framework: FATAL: Error inserting zaptel (/lib/modules/2.6.8-022stab050.1/extra/zaptel.ko): Invalid module format
[FAILED]
Waiting for zap to come online...Error: missing /dev/zap!
[root@OpenVZ libpri-1.2.1]# modprobe ztdummy
WARNING: Error inserting zaptel (/lib/modules/2.6.8-022stab050.1/extra/zaptel.ko): Invalid module format
WARNING: Error inserting zaptel (/lib/modules/2.6.8-022stab050.1/extra/zaptel.ko): Invalid module format
FATAL: Error inserting ztdummy (/lib/modules/2.6.8-022stab050.1/extra/ztdummy.ko): Invalid module format
FATAL: Error running install command for ztdummy