Date Added: May 2010
Relationships between application layer protocols in softswitch are explored in this paper. Two notions, i.e. protocol relationship and protocol grouping, are proposed, which are not clearly defined and even not paid much attention to before. On the basis of a well known protocol relationship named protocol conversion, three novel protocol relationships including protocol collaboration relationship, protocol cooperation relationship and protocol independent relationship are presented, so that protocol relationships are classified into four types. According to the functionality and purpose of each protocol, main protocols related to softswitch are divided into five groups. As to protocol conversion in softswitch, Information Flow Trail (IFT) is utilized to facilitate problem solving.