Routers are found everywhere on all levels of the Internet. Access networks allow homes and small businesses to connect to an Internet service provider; routers on a corporate network connect thousands of computers on a campus or enterprise; routers on backbone Connect ISPs and corporate networks on long-distance backbones.
1. Type of routers
The rapid development of the Internet has brought different challenges to the backbone network, enterprise network and access network. The backbone network requires that routers can perform high-speed routing and forwarding for a few links. Enterprise-class routers not only require a large number of ports and low prices, but also require simple and convenient configuration and provide QoS.
1.1 Type of routers - Access the router
Access routers connect small business customers within a home or ISP. Access routers have begun to not only provide SLIP or PPP connections, but also support virtual private network protocols such as PPTP and IPSec. These protocols need to be able to run on every port. Technologies such as ADSL will soon increase the bandwidth available to households, which will further increase the burden on access routers. Because of these trends, access routers will support many heterogeneous and high-speed ports in the future, and be able to run multiple protocols on each port, while avoiding the switched telephone network.
1.2 Type of routers - Enterprise-class routers
Enterprise or campus-level routers connect many end systems with the primary goal of interconnecting as many endpoints as possible in the cheapest way possible, and further requiring support for different qualities of service. Many existing enterprise networks are Ethernet segments connected by hubs or bridges. Although these devices are inexpensive, easy to install, and require no configuration, they do not support service levels. Conversely, a network involving routers can divide machines into collision domains and thus control the size of a network. In addition, routers also support a certain level of service, at least allowing for multiple priority levels. But routers are more expensive per port and require a lot of configuration work before they can be used. Therefore, the success or failure of an enterprise router depends on whether it provides a large number of ports with low cost per port, whether it is easy to configure, and whether it supports QoS. In addition, enterprise-class routers are required to efficiently support broadcast and multicast. Enterprise networks also deal with legacy LAN technologies, supporting multiple protocols, including IP, IPX, and Vine. They also support firewalls, packet filtering, and a host of management and security policies and VLANs.
1.3 Type of routers - Backbone routers
Backbone-level routers realize the interconnection of enterprise-level networks. The requirements for it are speed and reliability, and the cost is secondary. Hardware reliability can be achieved using technologies used in switched telephone networks, such as hot backup, dual power supplies, and dual data paths. These techniques are more or less standard for all backbone routers. The main performance bottleneck of backbone IP routers is the time it takes to find a route in the forwarding table. When a packet is received, the input port looks up the destination address of the packet in the forwarding table to determine its destination port. When the packet is shorter or the packet is destined to many destination ports, the cost of routing search is bound to increase. Therefore, putting some frequently accessed destination ports in the cache can improve the efficiency of route lookup. Whether it is an input buffer or an output buffer router, there is a bottleneck problem of route lookup. In addition to the performance bottleneck problem, the stability of the router is also a problem that is often overlooked.
1.4 Type of routers - Terabit routers
Of the three main technologies used in the future core Internet, fiber optics and DWDM are well established and readily available. If there is no router corresponding to the original bandwidth provided by the existing fiber optic technology and DWDM technology, the new network infrastructure will not be able to fundamentally improve the performance, so the development of high-performance backbone switches/routers (terabit routers) has become a an urgent request. Terabit router technology is still mainly in the experimental stage of development.
1.5 Type of routers - Multi-WAN routers
As early as 2000, when an engineer from Beijing Xin Omnidirectional was researching a Multi-Homing solution, he found that there is a huge market demand in China for multi-WAN port devices with all Ethernet protocols. With the successful research and development of Xinquanxiang products, the country's first dual-WAN router was born in 2002, and China's first dual-WAN broadband router was named NuR8021.
The dual WAN router has two physical WAN ports as external network access, so that the internal network computer can use two external network access lines at the same time through the load balancing function of the dual WAN router, which greatly improves the network bandwidth. The current dual-WAN routers mainly have the application advantages of "bandwidth aggregation" and "one network with two lines", which cannot be achieved by traditional single-WAN routers.
2. Classification introduction
2.1 Broadband Router
Broadband router is an emerging network product in recent years, which came into being with the popularization of broadband. The broadband router integrates functions such as router, firewall, bandwidth control and management in a compact box, and has the characteristics of fast forwarding capability, flexible network management and rich network status. Most broadband routers are optimized for China's broadband applications, can meet different network traffic environments, and have good grid adaptability and network compatibility. Most broadband routers adopt highly integrated design, integrate 10/100Mbps broadband Ethernet WAN interface, and built-in multi-port 10/100Mbps adaptive switch, which is convenient for multiple machines to connect to the internal network and the Internet, and can be widely used in homes, schools, offices, Internet cafes , community access, government, enterprises and other occasions.
2.2 Modular router
Modular routers mainly refer to routers whose interface types and some extended functions can be configured according to the actual needs of users. These routers generally only provide the most basic routing functions when they leave the factory. Select the corresponding module, different modules can provide different connection and management functions. For example, most modular routers can allow users to choose the type of network interface, some modular routers can provide functional modules such as VPN, some modular routers also provide firewall functions, and so on. Most routers today are modular routers.
2.3 Non-modular routers
Non-modular routers are all low-end routers, which are usually used at home. This type of router is primarily used to connect small business customers within a home or ISP. It not only provides SLIP or PPP connections, but also supports virtual private network protocols such as PPTP and IPSec. These protocols need to be able to run on every port. Technologies such as ADSL will soon increase the broadband available to households, which will further increase the burden on access routers. Because of these trends, such routers will support many heterogeneous and high-speed ports in the future, and be able to run multiple protocols on each port, while avoiding the switched telephone network.
2.4 Virtual router
Virtual routers are based on reality. Recently, some new technology breakthroughs in IP backbone network equipment have paved the way for the realization of new Internet services in the future. Virtual routers are one such new technology that enables some new Internet services. Through these new services, users will be able to control network performance, Internet addresses and routing, and network security. Israel RND Network Company is a manufacturer that provides solutions from local area network to wide area network. The company first proposed the concept of virtual routing.
2.5 Core Router
The core router, also known as the "backbone router", is the router at the center of the network. A router at the edge of a network is called an access router. Core routers and edge routers are relative concepts. They are all routers, but come in different sizes and capacities. A core router at one layer is an edge router at another layer.
2.6 Wireless router
A wireless router is a router with a wireless coverage function, which is mainly used for user Internet access and wireless coverage. The popular wireless routers on the market generally support four access modes: dedicated line xdsl/cable, dynamic xdsl, and pptp. It also has some other network management functions, such as dhcp service, nat firewall, mac address filtering and so on.
2.7 One-armed router
The concept of the one-armed router is that before the Layer 3 switch, the communication between the VLANs in the network can be implemented by ISL association. In that case, the router becomes a "one-armed router", and the data transmission between VLANs must be The router processes, and then outputs, so that most of the packets in the network will be transmitted directly between the switching devices at high speed without going through the router. The disadvantage of this routing method is that it is still a centralized routing strategy. Therefore, multiple redundant "one-armed" routers are generally set on the backbone network to share data processing tasks, thereby reducing the number of routers caused by routers. To avoid the bottleneck problem, redundant links can also be added, but if the data transmission volume between VLANs in the network is relatively large, a bottleneck will be formed at the router. One-armed routers are now largely replaced by Layer 3 switches
2.8 Wireless network router
A wireless network router is a communication device used to connect wired and wireless networks. It can send and receive wireless signals through Wi-Fi technology to communicate with devices such as personal digital assistants and notebooks. A wireless network router can easily establish a computer network without cables.
However, its speed may be affected by the weather when data is transferred over a wireless network outdoors. Other wireless networks include infrared, bluetooth and satellite microwave.
2.9 Intelligent flow control router
The intelligent flow control router can automatically adjust the bandwidth of each node, so that the network speed of each node can reach the fastest, without limiting the speed of each node, which is its biggest feature. Intelligent flow control routers are often used in On the backbone of telecommunications, such as Huawei and Cisco. Internet cafes, hotels, etc. are commonly used Netstar routers.
