Introduction of public and private network crossing technology SNP

Hi, all.

I'll introduce how to implement traversal between public and private networks through Huawei's SNP (Super Network Passport) technology.

With the rapid development of multimedia public video applications and broadband networks, an increasingly important issue is mentioned on the agenda: Most carriers and enterprises encounter networks where public and private addresses are mixed. How to implement traversal between public and private networks is a big problem. Generally, common services are accessed through the firewall on the private network. However, the structure of the H.323 IP package of the videoconferencing application is different from that of other applications. In the H.323 packet, the packet header contains not only the IP address but also the IP address in the packet. If the firewall is used to implement this function, the firewall must support the NAT function. In addition, a public IP address must be configured for each port on the private network that requires video communication externally. In practice, the operability is poor. In addition, the user needs to increase the cost. Huawei provides two solutions: The multimedia multi-service gateway is used to implement standard traversal between public and private networks. The advantage of this mode is that it is compatible with all standard H.323 terminals. The disadvantage is that additional network devices need to be purchased, which imposes cost pressure on users. The other solution is to implement the traversal between public and private networks without adding network devices through Huawei's SNP (Super Network Passport) technology.

Implementation Principle

The following figure shows the conceptual diagram.

The basic implementation principles are as follows:

Terminals between public and private networks communicate with each other according to the protocol requirements. When a private network terminal does not receive RTP streams from the peer end within a period of time after a call is set up, the private network requests the private communication process from the network through a private protocol. The network device processes the request and redirects the stream establishment process, in this way, a media communication process between the public network and the private network is established.

Networking Application

The following figure shows point-to-point networking without a GK.

Solution: Through the Super Network Passport (SNP) technology, the terminal A directly calls the terminal C through the IP address. The terminal and network do not need to be modified. (If the security level of the firewall is very high, the communication ports specified in the protocol must be opened.)

The following figure shows the networking of a point-to-point GK.

Solution: The SNP technology enables terminals on the private network and public network terminals to register with the GK. In this way, private network terminals can register with the public network gatekeeper (GK), and the terminals A and C can make calls to each other. The terminal and network do not need to be modified. 

The following figure shows the networking of the private network, public network, and public network.

Solution: The SNP technology can implement point-to-point interworking between terminals (A, B, C, D, and C) between the public network and private network. A conference that consists of multiple public networks and multiple private networks can be held by using the MCU. This networking mode is applicable to the operator network. 

The following figure shows the private network, public network, and private network.

Solution: Due to the direct route restriction between the private network and the private network, the SNP technology still cannot implement the direct point-to-point call of the private network (through the MCU). In this case, the Eudemon device can be added as the standard IP operation solution in the networking diagram. The Eudemon1 may be used as a candidate device. If the terminal D communicates with the terminal A and the B, the Eudemon is not required. However, if the terminal D communicates with other terminals inside the private network and the Eudemon is not installed on the private network egress, the Eudemon1 is mandatory.

With this solution, terminals can communicate with each other, and multipoint conferences can be initiated by the MCU. If the firewall is not deployed, you can use the Eudemon to implement the firewall. In this way, the networking will be more concise and economical.