User's Manual

SME VoIP System Guide, Version 1.5
Proprietary and Confidential
Chapter: Operation Setup – Bases/Handsets/SIP Sever
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16.3 Call Operations
In this section we describe call procedures in the SME VoIP system. We will narrow our description to call
transfer and call conference. Please view accompanied document for detail description of Handset
operations [3].
Some Definitions
There are three actors in a given transfer event, each playing one of the following roles:
Transferee: the party being transferred to the Transfer Target.
Transferor: the party initiating the transfer
Transfer Target: the new party being introduced into a call with the Transferee.
The following roles are used to describe transfer requirements and scenarios:
1. Originator - wishes to place a call to the Recipient. This actor is the source of the first INVITE in a
session, to a Facilitator or a Screener.
2. Facilitator - receives a call or out-of-band request from the Originator, establishes a call to the
Recipient through the Screener, and connects the Originator to the Recipient.
3. Screener - receives a call ultimately intended for the Recipient and transfers the calling party to the
Recipient if appropriate.
4. Recipient - the party the Originator is ultimately connected to.
Call Transfer - Requirements
Any party in a call session is able to transfer any other party in that session at any point in that session.
The Transferor and the Transferee are not removed from a session as part of a transfer transaction. This
requirement is needed so e.g. ring-back on transfer failure will not be lost.
The Transferor is aware of whether or not the transfer was successful
16.3.1 Initiating Calls
Enter Number
Press Green Button to start dialling
Originating Party