Industrial 4g router cellular backup internet connection in IOT

When we use point-to-point sub-interfaces to convert the NBMA network into a point-to-point link, the entire NBMA network will produce too many PVC partially interconnected or fully interconnected mesh structures, but this will have a certain negative impact and make A large amount of LSP flooding traffic is generated in the network. We all know that when an industrial router running IS-IS receives an LSP message, it will flood this LSP from all interfaces that have IS-IS protocol enabled except the receiving interface, so that other industries in the network All routers can receive this LSP. However, this flooding mechanism will produce excessive redundant LSP proliferation for a large number of partially interconnected or fully interconnected networks.

The so-called full interconnection or full mesh network topology means that all industrial routers are connected to other industrial-grade wireless routers (usually point-to-point sub-interfaces). In such a cellular backup Internet connection network, when a router receives an LSP flooded by a neighbor from an interface, it does not know whether the LSP has been received by other neighbor industrial 4g routers, so it will Other interfaces are flooded out, even if this LSP already exists in the link state database of other industrial 4g routers. If there are n network-wide routers in the network, then each industrial-grade LTE router in the network will spread n-2 redundant LSPs, so that the total flooded redundant LSPs will be (n-1)x( n-2), and the diffusion of these LSPs is redundant. If every industrial Netcom router refreshes an LSP, then this number will increase exponentially, resulting in a lot of waste of bandwidth resources.

In order to understand the redundancy phenomenon of LSP flooding in fully interconnected or highly interconnected networks, IS-IS provides a solution-IS-IS all-pass group, also known as Mesh group. The IS-IS all-pass group is defined in RFC2973. The so-called all-pass group is to assume that all industrial 3G routers are fully interconnected, and each industrial-grade full Netcom router will directly receive a copy of the original LSP flooded by other full-netcom industrial routers.

You can add the interfaces of the entire network industrial router to an all-pass group. There can be multiple all-pass groups on a full-net-com industrial router. The LSP flooding between interfaces in the all-pass group is restricted. LSP flooding is a normal operation, and it is also a normal LSP flooding operation between an industrial-grade 3G router interface that has not joined the all-pass group and the all-pass group.