Siemens M SERIES MG-2D - Manual (Page 5)

Multi Address Appearance on OpenStage 00.00.2007 I 5
Scope
This document specifies the Multiple Address Appearance (MAA) interface between an OpenStage SIP
phone and a SIP based communication server like Asterisk and describes the configuration.
A line is identified by an AoR resp. SIP URI and typically corresponds to a user. A line can appear on one
or multiple clients; in SIP terms, Multiple Line Appearance (MLA) means that each client registers as a
contact for the AoR concerned. A line that appears on multiple clients is known as a shared line. The
representation of a line on a given client is known as an appearance. The appearance at that client
which is normally used by the user associated with the line is known as the primary appearance, and
appearances at other clients are known as secondary appearances. Figure 1 shows an example of a
shared line with multiple appearances.
Line
OpenStage 2
OpenStage 1
Primary appearance
Secondary appearance
OpenStage 3
Secondary appearance
Figure 1: A shared line with multiple line appearances
A given client that is configured as a keyset can support multiple lines, also called Multiple Address
Appearance (MAA). The client will have a single appearance for each line it supports. From the client’s
point of view, a primary appearance of a line is known as a primary line and a secondary appearance of
a line is known as a secondary line. At present, the following restrictions apply for OpenStage SIP
phones:
Each client must have one and only one primary line;
A client must not have more than one appearance of the same line.
Figure 2 shows an example for an OpenStage phone with three addresses configured. Line 1 is the
primary line, all other lines are secondary lines.