最近和国内几个同行一起探讨了基于IMS的IPTV方案和非IMS的IPTV方案的区别,为了让更多的同行和读者有机会了解它们的异同,本文专门就在这两种环境下对内容点播服务的案例作一介绍。目前,AITS-IIF组织正在制订有关内容点播服务的规范,预计不久就将正式在行业内颁布。本文根据相关的规范编写而成,重点介绍CoD服务涉及到的功能和参考点,并讨论了在IMS和非IMS环境中,CoD功能架构的共同点和差异。本文同时也是IPTV国际标准系列文章之一。 Recently, several domestic counterparts have discussed the difference between IMS-based IPTV solutions and non-IMS-based IPTV solutions. In order to allow more peers and readers the opportunity to learn about their similarities and differences, this article focuses on content-on-demand Service case for an introduction. Currently, AITS-IIF is developing specifications for content on demand services and is expected to be formally promulgated in the industry soon. This article is written in terms of the relevant specifications, highlighting the features and reference points covered by CoD services and discussing commonalities and differences in CoD functional architectures in IMS and non-IMS environments. This article is also one of the IPTV series of international standards.