JVC VN-C215VP4U VFS, AFS, Size, Size, 7 (Low), VGA File, 1 (High), (Medium), QVGA File, (Variable, File Size), Packet Loss, Network Delay, Control Method, Network Jitter

Setting

Network Requirements

●Ensure that there is sufficient network bandwidth for the data volume to be sent out by VN-C215VP4U.

●Data volume to be sent by VN-C215VP4Uvaries with the settings and number of distributions.

●The maximum bit rate from VN-C215VP4U 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 File
Control Method		Size	Size
VFS	1 (High)	80 KB	27 KB
(Variable
	2	60 KB	20 KB
File Size)
	3	40 KB	13 KB
	4	30 KB	10 KB
	(Medium)
	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-C215VP4Uaccepts 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- C215VP4U 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-C215VP4Uvia 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-C215VP4U,the image frame rate may drop.

List of protocols and port numbers used by VN-C215VP4U

VN-C215VP4Uuses 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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