TKO TANDBERG 8000, Техническое описание

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Technical Description of TANDBERG 8000 with software version E3/B8
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one would first ping the default gateway, then the gatekeeper, and then the other
endpoint.
Traceroute
Traceroute does exactly that; it traces the route an IP-packet takes to reach its
destination and displays all router hops. Traceroute is very useful for seeing
exactly where there is a routing-problem in the IP-network, and for checking
where transport-delay is introduced.
4.1.3.12 NAT support
Network Address Translation is implemented to support small/home office applications
requiring a single endpoint behind a NAT router. NAT also supports the use of a
gatekeeper outside the NAT router.
4.1.3.13 Latency & Jitter
Latency is defined as the time between a node sending a message and receipt of the
message by another node. The TANDBERG systems can handle any value of latency-
however, the higher the latency, the longer the delay in video and audio. This may lead
to conferences with undesirable delays causing participants to interrupt and speak over
each other.
Jitter is defined as the difference in latency. Where constant latency simply produces
delays in audio and video, jitter can have a more adverse effect (e.g. the video may be
‘blocky’). Jitter causes packets to arrive out of order or at the wrong times, which again
leads to packet loss. TANDBERG can manage packets with jitter up to 100ms. If
excessive packet loss is detected, the TANDBERG systems will downspeed the
connection until acceptable packet loss is achieved.
4.1.3.14 Layer 4 Ports used in H.323 calls
The layer 4 ports used by the system in a H.323 call can be defined as follows:
•
Dynamic: The ports are allocated at random from 2048 to 65535.
•
Static: Will use the predefinded layer 4 ports listed in the tables below.
Point-to-point + Duo Video
Function Port Type
Gatekeeper Discovery (RAS) 1719 UDP
Q.931 Call Setup 1720 TCP
H.245 Range 5555—5556 TCP
Video Range 2326—2333 UDP
Audio Range 2326—2333 UDP
Data/FECC Range 2326—2333 UDP
Mul Duo Video
Function Port Type
Gatekeeper Discovery (RAS) 1719 UDP
Q.931 Call Setup 1720 TCP
H.245* Range 5555—5560 TCP
Video Range 2326—2365 UDP
Audio Range 2326—2365 UDP
Data/FECC Range 2326—2365 UDP