Technical Description of TANDBERG MCU with software version D3
D12925 Rev. 03
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4.1.4 Ethernet / LAN Interface (H.323)
The TANDBERG MCU have two RJ-45 jacks
5
for the Ethernet interface (manual or automatic
detection of 10/100Mb) and supports call rates from 56 kbps up to 2 Mbps. The ITU-T standard
H.323 v4 protocol is implemented in the TANDBERG MCU.
The following features are specifically relevant for this network interface:
4.1.4.1 Quality of Service features (QoS)
4.1.4.1.1 IP precedence
IP precedence is a classification of packets from 0 (low priority) to 7 (high priority). The
values 6 and 7 are typically reserved for congestion control. IP precedence helps a router
select what kind of traffic to prioritise. By means of queue mechanisms, it can select
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).
4.1.4.1.2 Diffserv
Diffserv is an extension of IP precedence, where one can set values from 0 to 63
(63=Highest priority).
5 Ethernet port no.2 is not used in software version D3.
