Merging call notifications in cross ringing systems

Multiple instances of an incoming call in an integrated system capable of communicating through multiple networks are associated such that the called party is provided a single (merged) notification along with options to select among available call types. The call is established using a selected network and end device registered to the called user. Association of the instances is accomplished by comparing caller identity derived from a variety of information associated with the calling party. Conversation or correlation IDs are used to associate the instances as being for the same call and with other related communications such as a related instant messaging session.