You are here: CSP Developer’s Guide: Common Channel Signaling > 4 SS7 Call Control for ISUP > Call Modification Messages
Overview
This section includes information about messages that involve requesting, rejecting, and completing call modifications.
CMR: Call Modification Request/Call Modification Reject
Message sent in either direction to indicate that the call modification request has been rejected.
CMC: Call Modification Complete
Message sent in either direction to indicate that the call modification request has been accepted
CMR from Host -- CMC from Network
MR from Host -- CMRJ from Network
MR from Network -- In-Call Modification Disabled
CMR from Host -- Local In-Call Modification Disabled
