| 摘要 |
An instant message (IM) connection is established at an IM server in the usual manner, under the policies and security rules promulgated by the IM service provider. Using this connection to the IM server, an offline IM chat request is made at the IM server for establishing an offline connection directly between consenting IM clients. The request may be included in a message to the IM server from a client, or the request may be in the form of IM session parameter, for the client, that authorizes an offline chat as the preferred type of IM session under certain conditions, such as the IM server being unavailable, IM server loading level or other factors that are under the control of the server. The conditions may also specify the presence of other IM clients as a criterion for establishing an offline chat, whether present in an online chat session or merely available. |
