What are the operating modes of network camera monitoring

In the working mode of the monitoring project, network camera monitoring generally runs around four modes, namely, gateway mode, bridge mode, bypass mode, and listening mode. This article will briefly introduce these four operating modes and their principles:

Gateway Mode

The principle is to use this machine as a gateway for other computers (set the video surveillance to be directed to this machine by the computer's default gateway), which can be used as a single network card mode, dual network card or even multi network card mode. The original PROXY mode is basically eliminated now. Adopted, currently commonly used is the NAT store-and-forward method; in a nutshell, it is a bit like a router working method; so the control is extremely strong, but because of the store-and-forward method, the performance is somewhat lost; but the efficiency is already better; If the gateway dies, the entire network is paralyzed;

Bridge Mode

The principle is that the dual network card is made into a transparent bridge, and the bridge works at the second layer, so it can be simply understood that the bridge is a network cable, so the function is * with almost no loss; WINFCAP itself does not support this mode; this mode can be said It is * ideal, even if the bridge is broken, as long as it is a simple jumper, because the bridge is transparent, it can be regarded as a network cable, even if the bridge is broken, it can be understood that the network cable is broken. Change it; support multiple VLANs, Almost all network conditions such as wireless, thousands of M, M, VPN, multi-export, etc., the reason is very simple, because the transparent bridge understands that it is a network cable;

Bypass mode

The principle is to use ARP technology to establish a virtual gateway, which is only suitable for small-scale network monitoring, and there can be no limited bypass mode in the environment; routing or firewall restrictions or the installation of ARP firewalls by the supervised computer will result in failure to bypass, because you It is contradictory because it is bypassing while bypassing the bypass. At the same time, if multiple bypasses at the same time will cause chaos and intermittent network; but as long as the premise is that the method is simple deployment and convenient installation settings;

Audit mode

The principle is to bypass jian listening, just as there is a parallel listening on the side of the dian dialect of two people, so the efficiency is very low. This mode requires the use of a shared HUB or switch mirror; however, the use of an old-style shared HUB will affect Network export function; if the mirror mode is adopted, on the one hand, it is necessary to invest in supporting two-way mirror switch equipment, on the other hand, it requires professional personnel to set up the mirror switch, but some switches will block the switch or reduce the network function during the blocking process; and fundamental The problem is that the function is lost; the principle defect of the listening mode makes UDP blocking unavailable, and it will severely lose the network camera bandwidth, and at the same time can not achieve good functions such as traffic limiting; generally speaking, at least 40% of the loss Network function; and WINFCAP works in this mode, precisely because of such a function, it basically determines the defects generated.