Abstract: VoLTE is the goal of the program for LTE voice service, it needs IMS system to provide operational support,The single factory networking solution of VoLTE core network, satisfied ending to ending test call service in short time, but also easy to be limited by single manufacturer‘’s technical constraints, integrating wireless systems、 HSS/ HLR, packet domain and other considerations, a reasonable choice of equipment from different manufacturers VoLTE IMS network by different area, under the control of network construction investment premise, both to ensure the rapid on-line services, but also to bring security for network security. From the actual situation existing VoLTE single factory single-domain network, analyzes the feasibility of IMS core network element between different manufacturers of networking equipment programs, and a variety of analysis and recommendations networking schemes, in order for the VoLTE expand the deployment of reference and to provide guidance for the actual construction of the respective network operators.

Key words:  IP multimedia subsystem(IMS), call session control function(CSCF), voice over LTE(VoLTE), networking, policy and charging rules function(PCRF)