Clarification needed - H245 Specification

Hi, I want a clarification about the H245 Annex I defined for AMR codec: What is the parameter "bitRate" defined for? Is it defined for AMR mode change out-of-band? I want to know how the AMR mode changes can be performed out-of-band using H245? For example, assume that we are having a voice call with 12.2kbps and during the call, how can we change it to 7.4kbps using H245? Please let me know at the earliest... Thanks Venkata