TL;DR: In this article, a NAT information provider, NIP, allows messages sent by a NIP to reach the client, while implementing the routing unit ensures that the client is "behind" the NAT in the network sense.
Abstract: The invention relates to a network node for facilitating traversal of NATs. The node includes a NAT, a client such as e.g. a STUN client, configured for determining NAT-related information for the NAT by exchanging one or more messages with a server such as e.g. a STUN server, and a routing unit configured for routing the messages exchanged between the client and the server via the NAT. Implementing the client on such a network node allows messages sent by a NAT information provider, NIP, to reach the client, while implementing the routing unit ensures that the client is "behind" the NAT in the network sense. In this manner, the NIP may request NAT behaviour discovery and obtain NAT-related information from the client and is able to later provide appropriate NAT-related information to terminals in local networks, thereby enabling the terminals to traverse the NATs that they are behind.
TL;DR: In this article, an NAT gateway disaster recovery implementation method and a system thereof is described. But the authors do not reveal the implementation of the NAT gateway this article and the NAT device module.
Abstract: The invention discloses an NAT gateway disaster recovery implementation method and a system thereof. The system comprises a computing virtualization resource pool, a switch, an LACP convergence module, a synchronization module, an NAT device module and a public network gateway module, and the NAT device module comprises an NAT device D1 and an NAT device D2. The method comprises: calculating message flow sent and received by the virtualization resource pool, realizing message flow convergence of the NAT device D1 and the NAT device D2 by the LACP convergence module, and establishing a VxLAN tunnel between the NAT device D1 and the NAT device D2 by the synchronization module; both the NAT device D1 and the NAT device D2 forwarding the message flow of the switch to the public network gatewaymodule, or forwarding the message flow of the public network gateway module to the switch; and when each address link is connected for the first time, the NAT device D1 and the NAT device D2 newly establishing a session identifier, and redirecting and transmitting a newly connected first message between the NAT device D1 and the NAT device D2 through the VxLAN tunnel. According to the invention,all messages can be ensured to find correct sessions, the efficiency and accuracy are ensured, and the equipment deployment is simplified.
TL;DR: A solution SPNT (Shortes Path for NAT Traversal) is proposed, which can traverse all NATs in the application layer not changing the existing NAT, and avoids the pitfalls of using any of the other methods alone.
Abstract: The NATs caused the SIP end-to-end application to become extremely difficult.In this paper we analyzed several kinds of method of NAT traversal for SIP and their pitfalls, proposed a solution SPNT(Shortes Path for NAT Traversal). The basic idea is that the proxy judges the NAT type which the SIP device is behind through the information interacting between the proxy and the SIP device, It takes different methodology to traverse the NAT by the NAT type for the SIP signaling, and the shortest associated media data path between the devices are dynamic established by the connectivity checks to the media addresses. This solution can traverse all NATs in the application layer not changing the existing NAT,and avoids the pitfalls of using any of the other methods alone.