- H.450
H.450 refers to a set of standards created by the International Telecommunications Union (ITU) to define several Supplementary Services of the packet based telecommunication protocol known as
H.323 . It parallels another set of standards known asQSIG which define similar services for ISDN based networks.* H.450.1, Supplementary Services FrameworkThe general mechanism for delivering supplementary services is explained in this paper. Supplementary services messages are exchanged by means of ROSE (Remote Operations Service Extension).
* H.450.2, Call Transfer Supplementary ServiceE.g. explains how a party-B can turn an active call between party-A and party-B into a call between party-A and a new party-C.
* H.450.3, Call Diversion Supplementary ServiceE.g. explains how an IP phone can activate a diversion to e.g. a cell phone.E.g. explains how an IP phone can interrogate whether it has any active diversion.
* H.450.4, Call Hold Supplementary Service E.g. explains how a call can be put on hold and be fed with a music on hold.
* H.450.5, Call Park and Pickup Supplementary ServiceThink of big warehouse, where a call is coming in at the front-desk for Mrs. Smith.The front-desk parks the call and broadcasts via the intercom: "Mrs. Smith, please 223".Mrs. Smith proceeds soon after to the next wall phone, dials 223 and gets the call.
* H.450.6, Call Waiting Supplementary Service Explains how to signal a second call to an IP phone already engaged in an active call.
* H.450.7, Message Waiting Indication Supplementary Service Explains elements related to voicebox systems and how these can be implemented by means of H.323.
* H.450.8, Name Identification Supplementary Service Explains how names are displayed or how to intentionally call incognito.
* H.450.9, Call Completion Supplementary Service Explains how to schedule an automatic call-back request in case of a remote party being busy in a call or being absent for a while and becoming available later on.
* H.450.10, Call Offer Supplementary Service A variation of Call Waiting. Also known as "Camp-On".
* H.450.11, Call Intrusion Supplementary ServiceExplains how e.g. the secretary of a CEO can intentionally and legally intrude into a call of her boss, in order to communicate urgent information.
* H.450.12, Common Information Additional Network Feature for H.323A means to communicate additional miscellaneous information between endpoints. E.g. whether certain features are available, and/or allowed.
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