Technical Description of
TANDBERG Gateway
with software version G2
D13192 Rev. 02
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which packets to send first and which to throw away. Some information/traffic is time
critical while other is not, and classification is used to differentiate this traffic.
One may set separate IP precedence for Signalling, Audio, Video and Data (values 1 – 7)
as well as turn IP precedence off.
The
auto
setting uses the following values for IP precedence:
Signalling=6
Audio/Video=4
Data=3 (e.g. FECC commands)
This means that in
auto,
IP precedence has the value 6 (i.e. signalling value) while both
audio and video value is 4; data value is 3. Setting the IP precedence value in system’s
menu is actually setting the signalling value. The audio/video and data values are
changed accordingly in respect to the signalling value (i.e. audio/video value = - 2; data
value = - 3).
4.1.5.1.2
Diffserv
Diffserv is an extension of IP precedence, where values from 0 to 63 (63=Highest
priority) can be set.
4.1.5.1.3
IP type of service (TOS)
TOS helps a router select a routing path when multiple paths are available.
Delay-
tells router to minimize delay
Throughput-
tells router to maximize throughput
Reliability-
tells router to maximize reliability
Cost-
tells router to minimized cost
Off-
Turns TOS off
4.1.5.1.4
Resource-Reservation Protocol (RSVP)
RSVP is a protocol that allows the TANDBERG Gateway to request the network to
reserve the bandwidth needed for the IP meeting.
4.1.5.2
IP adaptive bandwidth management
•
The TANDBERG Gateway never produces more traffic than needed for better
utilization of network resources. Most of the data sent in a videoconference is video
data. Thus, by incorporating smart video algorithms, the codec sends no more video
data than necessary. Little movement in the picture gives low bit rate; while a lot of
movement gives higher bit rate.
•
The TANDBERG Gateway regulates outgoing and incoming media bit rates by
means of flow control signalling.
