6.Multimedia Resource Function Controller (MFRC)

The Multimedia Resource Function (MRFC) is need to support bearer-related services, such as conferencing, announcement to a user or bearer transcoding. the MRFC interprets SIP signaling receive via S-CSCF and uses the Media Gateway Control Protocol (MEGACO) or H.248 instruction to control the Multimedia Resource Function Processor (MRFP). for charging purchasing, the MFRC is able to send accounting information to the CCF and OCF 

the multimedia Resource Function Processor (MRFP) allocates user-plane resource as instructed by the MFRC

7.Media Gateway Control Function (MGCF)

the Media Gateway Control Function  (MGCF) connect IMS communications to legacy CS user. all incoming CS call control signaling ex: ISDN,User Part (ISUP) or the Bearer Independent Call Control (BICC) message are converted into SIP and vice versa

for the lower signaling layer, a Signaling Gateway (SGW) convert standard SS7 MTP or IP-base SCTP (Stream control Transmission Protocol ) message into the TCP or UDP format and forwards them to MGCF

8.Breakout Gateway Control Function (BGCF)

the Breakout Gateway Control Function (BGCF) determines where signaling breakout to the CS domain occurs, if the breakout occurs in the same network, BGCF select an MGCF in the same network to convert SIP signaling into ISUP/BICC signaling to CS domain. if the breakout come in another network, BGCF select an BGCF in  an different network, then other BGCF select own MGCF to convert SIP signaling to ISUP/BICC to CS domain