Fix lỗi không config được DAHDI of Asterisk on Centos 7

1. Lỗi :
- Khi run

make && make install && make config

Báo lỗi như sau:

make -C linux all
make[1]: Entering directory `/usr/src/dahdi-linux-complete-2.11.1+2.11.1/linux'
make -C drivers/dahdi/firmware firmware-loaders
make[2]: Entering directory `/usr/src/dahdi-linux-complete-2.11.1+2.11.1/linux/drivers/dahdi/firmware'
make[2]: Leaving directory `/usr/src/dahdi-linux-complete-2.11.1+2.11.1/linux/drivers/dahdi/firmware'
You do not appear to have the sources for the 3.10.0-862.11.6.el7.x86_64 kernel
installed.

2. Nguyên nhân:
Do kernel thiếu các gói tương ứng nên lỗi khi make.

3. Cách xử lý:
- Cài đặt update lại kernel

yum install kernel-devel

https://striker24x7.blogspot.com/2013/05/steps-to-reinstall-or-upgrade-dahdi.html