Use the change ip-codec-set<codec set number> command to create a codec set.
Procedure
Ensure that G.711A,
G.711MU, G.729, G.729A, G.723, or G.726A are the only codecs administered.
Note that the G.723 and G.726A codecs can only be used for DMCC applications,
which use Client Media mode.
Verify that the Silence Suppression field is set to n.
It is recommended that
you accept the default packet size.