Restrictions on the Number of Distributions for VN-V25U/26U

The maximum number of distributions for VN-V25U/26Uis 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

Distribution

Maximum

Total

at maximum

number of

maximum bit

bit rate

distributions

rate

 

 

 

1 Mbps and

20

20 Mbps

below

 

 

 

 

 

5 Mbps and

4

20 Mbps

below

 

 

 

 

 

10 Mbps and

2

20 Mbps

below

 

 

 

 

 

Larger than

1

Maximum

10 Mbps

 

configurable

 

 

value

 

 

(24 Mbps)

 

 

 

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

Preset bit

Maximum

Total

number of

maximum bit

rate

distributions

rate

 

 

 

 

0.6 Mbps

20

12 Mbps

and below

 

 

 

 

 

3 Mbps and

4

12 Mbps

below

 

 

 

 

 

6 Mbps and

2

12 Mbps

below

 

 

 

 

 

Larger than

1

Maximum

6 Mbps

 

configurable

 

 

value (8

 

 

Mbps)

 

 

 

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.

 

Maximum

Maximum

Total bit

number of

number of

rate

distributions

distributions

 

for JPEG

for MPEG4

 

 

 

20 Mbps and

2

2

below

 

 

 

 

 

 

 

 

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/26Uwill 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/26Uvia 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.

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