1. download the codec so file based your CPU, the linux command is for 32bit linux

wget http://asterisk.hosting.lv/bin162/codec_g729-ast16-icc-glibc-pentium4.so

for 64bit linux

http://asterisk.hosting.lv/bin162/codec_g729-ast16-icc-glibc-x86_64-pentium4.so

2. copy the .so file to asterisk lib folder for 32bit linux

mv ./codec_g729-ast16-icc-glibc-pentium4.so /usr/lib/asterisk/modules/

for 64bit linux

mv ./codec_g729-ast16-icc-glibc-x86_64-pentium4.so /usr/lib/asterisk/modules/

or

mv ./codec_g729-ast16-icc-glibc-x86_64-pentium4.so /usr/lib64/asterisk/modules/

3. load the codec

for 32bit linux

asterisk -rx "module load codec_g729-ast16-icc-glibc-pentium4.so"

for 64bit linux

asterisk -rx "module load codec_g729-ast16-icc-glibc-x86_64-pentium4.so"

system is supposed to give

Loaded codec_g729-ast16-icc-glibc-pentium4.so

or

Loaded codec_g729-ast16-icc-glibc-x86_64-pentium4.so

4. confirm

asterisk -rx "core show translation"

if you could read number under g729 column, it means your system support g729 codec now

5. auto-load

echo "load => codec_g729-ast16-icc-glibc-pentium4.so" >> /etc/asterisk/modules.conf

or

echo "load => codec_g729-ast16-icc-glibc-x86_64-pentium4.so" >> /etc/asterisk/modules.conf