JVC VN-V25U VN-V26U ユーザーズマニュアル

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Restrictions on the Number of 
Distributions for VN-V25U/26U
The maximum number of distributions for 
VN-V25U/26U is determined by the settings as 
well as requirements from the client.
When only JPEG images are distributed, the 
maximum number of distributions is determined 
based on the highest bit rate within the stream. 
When a distribution request that exceeds the 
maximum number of distributions is received, 
this request is denied. For example, if Client A 
requests for and receives data at 1 Mbps, while 
Client B requests for and receives data at 
5 Mbps, the maximum number of distributions is 
4 streams according to the table below.
Maximum number of distributions when only 
JPEG data is distributed
When only MPEG4 images are distributed, the 
maximum number of distributions is determined 
by the preset bit rate. When a distribution 
request that exceeds the maximum number of 
distributions is received, this request is denied.
When distributing only MPEG4 data
When both JPEG and MPEG4 images are 
distributed simultaneously, distribution up to two 
clients for JPEG and MPEG4 respectively is 
possible. However, distribution requests that 
exceed a total bit rate of 20 Mbps will be denied.
Insufficient network bandwidth
When there is insufficient bandwidth, the 
number of JPEG frames (frame rate) that the 
client can acquire will decrease. Delay will also 
occur in the distribution of images. In the case of 
MPEG4, noise interference may occur and 
playback may fail.
There may be a longer delay or interruption in 
the audio.
Network Delay
When the client acquires JPEG via TCP, 
VN-V25U/26U will send out data while checking 
the ACK from the client at the same time. For 
networks with considerable delay, data cannot 
be sent out until ACK is received, and therefore 
the frame rate will drop. In the case of MPEG4, 
noise interference may occur and playback may 
fail.
Audio may be interrupted.
Decrease in the frame rate due to network delays 
can be eliminated by receiving data via multicast.
Network Jitter
When there is considerable network jitter, delay 
time may be prolonged and the image frame rate 
may drop. In the case of MPEG4, noise 
interference may occur and playback may fail.
Audio may be interrupted.
Packet Loss
When acquiring images from VN-V25U/26U via 
TCP, packet loss may be recovered by TCP 
transmission. When there is considerable delay 
in the network, however, missing data may occur 
and the image frame rate may drop. In the case 
of MPEG4, noise interference may occur and 
playback may fail. 
Audio may be interrupted.
When packet loss occurs during multicast 
sending from VN-V25U/26U, the image frame 
rate may drop. In the case of MPEG4, noise 
interference may occur and playback may fail.
Audio may be interrupted.
Distribution 
at maximum 
bit rate
Maximum 
number of 
distributions
Total 
maximum bit 
rate
1 Mbps and 
below
20
20 Mbps
5 Mbps and 
below
4
20 Mbps
10 Mbps and 
below
2
20 Mbps
Larger than 
10 Mbps
1
Maximum 
configurable 
value 
(24 Mbps)
Preset bit 
rate
Maximum 
number of 
distributions
Total 
maximum bit 
rate
0.6 Mbps 
and below
20
12 Mbps
3 Mbps and 
below
4
12 Mbps
6 Mbps and 
below
2
12 Mbps
Larger than 
6 Mbps
1
Maximum 
configurable 
value (8 
Mbps)
Total bit 
rate
Maximum 
number of 
distributions 
for JPEG
Maximum 
number of 
distributions 
for MPEG4
20 Mbps and 
below
2
2
VN-V25U_26U_EN.book  Page 25  Friday, January 18, 2008  2:56 PM