When the enterprise users use IMS-based enterprise managed unified communications service, because of involving different network, service platform and the interaction between network elements, it will face some technical problems such as authentication, firewall traversal and group file sharing. 在企业用户使用基于IMS的企业托管式融合通信服务时,涉及端到端不同网络、业务平台及网元之间的交互与传输,将面临认证、防火墙穿越和群文件共享等方面的技术问题。