Method and device capable of transversing NAT equipment in monitoring network

Abstract

A method capable of transversing NAT (Network Address Translation) equipment in a monitoring network comprises the following steps: receiving a reply message sent by a management server through the NAT equipment, analyzing a Tag in the reply message, and adding the Tag information in a corresponding NAT session table entry so as to form a Tag forwarding table; finding the Tag forwarding table according to the Tag when the NAT equipment receives the message which is sent to an internal network by an external network, and then judging whether the protocol type, the global IP address and the port number in the found table entry are in one-to-one correspondence with those of the current message, if yes, translating a destination IP address and a destination port number of the current message into the internal network IP address and the port number in the table entry so as to forward out form an internal network interface; otherwise, translating the destination IP address of the message into the internal network IP address in the table entry so as to forward out from the internal network interface. With the method and the device which fully combine the characteristic of monitoring business, the technology of safely and conveniently transversing the NAT is realized.

Description

technical field [0001] The invention relates to the field of designing video monitoring, in particular to a method and a device for traversing NAT equipment in a monitoring network. Background technique [0002] NAT (Network Address Translation, Network Address Translation) is the process of converting the IP address in the IP datagram header to another IP address. In practical applications, NAT is mainly used to enable private networks to access public networks. This way of using a small number of public IP addresses to represent more private IP addresses will help slow down the depletion of available IP address space. Its original design purpose is to realize the function of private network accessing the public network, and later expanded to realize the application of address translation when accessing between any two networks. This application document refers to these two networks as internal network (intranet) ) and external network (external network), usually the priv...

AI Technical Summary

Problems solved by technology

The problem with the traffic drainage solution is that it is necessary to trigger the sending of data packets from the internal network device to the external network in advance, so as to establish a NAT SESSION entry on the NAT device. This is cumbersome in the process of monitoring business, and sometimes it is not allowed

In addition, there are also deficiencies in security. The more port numbers are opened to send data packets from the internal network to the external network, the worse the security of the entire system will be.

The problem with the tunnel solution is that it consumes a certain amount of equipment and network transmission

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