Table 14.1 SIP Conference Models
CONFERENCE MODELS HOW IT WORKS- Endpoint mixing
Small conferences with three to nine
participants. One endpoint handles
signaling and also acts as media mixer,
and is required to stay until the end of
the conference. Endpoint bandwidth is
often the limiting factor. - SIP Server and distributed media
The central SIP server establishes a full
mesh of point-to-point RTP streams
between all participants. Each
participant mixes all the media it
receives and plays out its own media
to every participant. Media latency is
minimized and end-to-end security
maximized. However, media
synchronization can be difficult. - Conference Bridge – as in PSTN conferences
Medium-sized conferences. Users dial
in for the conference or the bridge can
dial out to bring a participant into the
conference. The bridge mixes media
from other directions for each
participant. The conference server also
houses the conference applications.
The bridge could support PSTN, SIP,
and H.323, for example. - Ad hoc centralized conference
Two users may transition to a multiparty
conference by having one user making
the transition using SIP call control. - Large multicast conference
Very large-scale conferences, up to
millions of users. Users join a multicast
address announced on the Web, by
e-mail, or Session Announcement
Protocol (SAP), or are invited to join
using SIP.
MULTICAST NETWORKGATEWAYCONFERENCEBRIDGE- MULTIPOINT
- INITIAL POINT-TO-POINT PSTN
GATEWAYCONFERENCEBRIDGEPSTNGATEWAYDISTRIBUTED MEDIASIP ServerPSTNCONFERENCE AND ACTSENDPOINT INITIATES
AS MEDIA MIXERGATEWAY
PSTNSIP Conferencing 247