Kannel error: AT2[wavecom1]: at2_device_thread: open_at2_device failed. System error 13: Permission denied

If you ever run into below error on kannel.
please note that this is due to permission to your USB or Serial Model

2013-08-02 22:50:01 [2853] [6] ERROR: System error 13: Permission denied
2013-08-02 22:50:01 [2853] [6] ERROR: AT2[wavecom1]: at2_device_thread: open_at2_device failed.
2013-08-02 22:50:01 [2853] [6] ERROR: System error 13: Permission denied
2013-08-02 22:50:01 [2853] [6] ERROR: AT2[wavecom1]: Couldn't connect (retrying in 10 seconds).
2013-08-02 22:50:01 [2853] [6] INFO: AT2[wavecom1]: opening device
2013-08-02 22:50:01 [2853] [6] ERROR: AT2[wavecom1]: open failed! ERRNO=13
2013-08-02 22:50:01 [2853] [6] ERROR: System error 13: Permission denied
2013-08-02 22:50:01 [2853] [6] ERROR: AT2[wavecom1]: at2_device_thread: open_at2_device failed.
2013-08-02 22:50:01 [2853] [6] ERROR: System error 13: Permission denied
2013-08-02 22:50:01 [2853] [6] ERROR: AT2[wavecom1]: Couldn't connect (retrying in 10 seconds).

You can run below command for serial modems:

First run the su:

[md@sms02 ~]$ su
Password:
[root@sms02 md]#

chmod 777 /dev/ttyS*

or for USB modem run below command,

[root@sms02 md]# chmod 777 /dev/ttyS*

you may want to add it to your rc.local to apply at the boot time:

[root@sms02 md]#echo 'chmod 777 /dev/ttyS*' >> /etc/rc.local