Advice

While the G.722 SIP Audio Codec is a better sounding codec, the G.711 ulaw SIP Audio Codec is more widely used in North America. 

It is recommended that the G.711 ulaw codec be enabled in the 2nd spot of the Audio Codec list in the Telephony section of Core Manager if you primarily make or receive calls to North America. 

If you primarily make or receive calls outside of North America, it is best to enable G.711 alaw as the 2nd codec being more common outside North America.