ZXUN iMG, as a media gateway in ZTE mobile soft-switch solution, is located at access layer of GSM/UMTS/TD-SCDMA/CDMA2000. It provides media processing functions for voice service or circuit switch (CS) domain data service, including voice stream format conversion, bearer conversion, and inter-network interworking, etc. ZXUN iMG supports service-bearing functions of VMSC, TMSC, and GMSC in GSM/UMTS/TD-SCDMA/CDMA2000 network, and realizes networking flexibly. ZXUN iMG could be smoothly evolved to IM-MGW/MRFP in IMS network and protects operators' investment.