Setting

Network Requirements

Ensure that there is sufficient network bandwidth for the data volume to be sent out by VN-C215V4U.

Data volume to be sent by VN-C215V4U varies with the settings and number of distributions.

The maximum bit rate from VN-C215V4U is about 9 Mbps.

Estimation of total bit rate

The JPEG file size per frame varies with the encoding settings as well as input video signals. The following table may be used as a reference. When VFS is selected, the quantization table during JPEG encoding will be maintained and the file size will increase/decrease according to the input signals. When AFS is selected, encoding will be performed such that the average size of multiple JPEG images is the target file size.

Picture Quality

VGA File

QVGA

Control Method

Size

File Size

 

 

 

 

VFS

1 (High)

80 KB

27 KB

(Variable

 

 

 

2

60 KB

20 KB

File Size)

 

 

 

 

3

40 KB

13 KB

 

 

 

 

 

4 (Medium)

30 KB

10 KB

 

 

 

 

 

5

25 KB

8 KB

 

 

 

 

 

6

20 KB

7 KB

 

 

 

 

 

7 (Low)

15 KB

5 KB

 

 

 

 

AFS

 

Selection

Selection

(Average File Size)

may be

may be

 

 

made from

made from

 

 

the range

the range

 

 

between 10

between 3

 

 

and 100 KB

and 33 KB

 

 

 

 

VN-C215V4U accepts requests from up to a maximum of 5 clients. In addition, it also allows transmission of 1 multicast stream. The total frame rate refers to the sum of these frame rates. For example, when 10 fps is requested by 2 clients, and in addition multicast is transmitted at a rate of 10 fps, the total frame rate will be:

10 + 10 + 10 = 30 fps

If the JPEG file size per frame is 30 KB, then the total bit rate will be:

30 KB x 30 fps = 900 KB/s = Approx. 7.2 Mbps

Insufficient network bandwidth

When there is insufficient bandwidth, the number of JPEG frames (frame rate) that the client can acquire will decrease.

Network Delay

When the client acquires JPEG via TCP, VN- C215V4U 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.

Drop of frame rate due to network delay can be eliminated by sending data via multicast.

Network Jitter

When there is considerable network jitter, delay time may be prolonged and the image frame rate may drop.

Packet Loss

When acquiring images from VN-C215V4U via TCP, packet loss may be recovered by resending by TCP. When there is considerable delay during resending, however, missing data may occur and the image frame rate may drop. When packet loss occurs during multicast sending from VN-C215V4U, the image frame rate may drop.

List of protocols and port numbers used by VN-C215V4U

VN-C215V4U uses the protocols and port numbers listed below. Ensure that these ports are allowed through the firewall when a firewall is to be installed.

Protocol/Port No.

Purpose of Use

 

 

TCP/80

JPEG acquisition,

 

Web Settings page,

 

API

 

 

TCP/20, 21

FTP

 

 

TCP/25

Mail delivery

 

 

TCP/User Setting No.

Alarm sending

 

 

UDP/User Setting No.

Alarm sending

 

 

UDP/User Setting No.

Multicast sending

 

 

UDP /123

SNTP

 

 

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JVC VN-C215V4U manual Network Requirements