Do you know what a router is?

‍ In the 19th century, with the invention of telegraph, telephone and fax, information transmission efficiency was greatly improved, but how to transmit large data information in real time was still a problem. It was not until the advent of the Internet in the 1990s that large amounts of data and information could be transmitted in real time through the network. In the Internet, there is a device silently assume the important task of data information forwarding, it is the protagonist we want to talk about today - router.

A router is a hardware device that connects two or more networks and acts as a gateway between networks. It reads the IP address in each packet to determine how to deliver it. One function of a router is to connect different networks, and another is to choose the best route for transmitting information.

Just say the concept estimate we still feel too abstract, then we start from the familiar Internet speed, to have a look at the development and change of router in the network era!

In 1994, China passed a 64K international special line, full function access to the Internet, since then was officially recognized by the international as a country with full function Internet, China's Internet era began from then on. In the beginning, the Internet was mainly used by universities and research institutes as a research tool for academic discussion. With the rise of portal websites such as Sina, Sohu and NetEase, more and more ordinary people use portal websites to access the Internet. Most Internet users at that time used modems (also known as "cats") to dial up to the Internet through telephone lines.

After a minute or two of cat squeaking, the computer finally connected to the Internet, and users began to enjoy the super-slow speed of 56 KBPS. At 6 yuan an hour, Internet access is a luxury. Smart Internet users unlock the Internet posture is like this: dial up to the Internet, quickly open all the pages to see, then disconnect from the network, and then peruse the web content.

In those days, we usually had only one computer to surf the Internet, and we didn't have a home router, so we didn't know much about routers. But in fact, there are routers in the network, just used in the carrier network, we do not feel.

Routers on carrier networks provide 10M or 100M Ethernet interfaces for PSTN access and form x. 25 or frame relay wide area networks (wans) to forward data. They use routing protocols such as OSPF and BGP to calculate the optimal path and send data packets to the destination in the longest matching and point-by-point forwarding mode.

Do you know what a router is?

After a few more years, ADSL finally appeared. ADSL is a brother of broadband access, compared with Modem dial, can achieve up to 1 Mbps, down 8 Mbps broadband access speed, not only the Internet speed improved a big cut, Internet at the same time can also call.

At that time, ADSL dial Internet but very avant-garde, the village who if use ADSL dial Internet, is absolutely leading the trend, walk on the road, will accept the envy of others at any time. After ADSL, more dial-up Internet access methods based on DSL technology appear on this basis, such as ADSL2, ADSL2+, VDSL, VDSL+ and so on, collectively known as xDSL (Digital Subscriber Line).

XDSL uses signal processing techniques to add or retrieve more digital data to an analog line to achieve high transmission rates (theoretical values up to 52 Mbps). With the development of the Internet, there is no pressure to make friends or watch a video at home. Behind the rapid forwarding of data, what improvements have been made to routers in carrier networks?

At this time, the router is also updated, the access side interface is upgraded from 10 or 100 MBIT/s Ethernet interface to gigabit Ethernet interface, so that the network bandwidth is also upgraded to gigabit Ethernet interface. At the same time, the router has been upgraded from x.25 or Frame relay only to ATM support. ATM is a packet-switching technology based on cell. It uses fixed-length labels and only needs to maintain a label table much smaller than the routing table. Compared with IP routing, the forwarding performance is greatly improved. The wide area network bandwidth has also been greatly increased, up to 622 Mbps, has been able to meet the majority of Internet users online experience.

This truly lets the netizen have the life to reach the peak feeling is the current optical fiber access (referred to as PON) era. Compared to xDSL, PON networks can achieve the highest gigabit network access speeds. High-definition video, online games, all free pressure, super high Internet speed let you cool to blast. Hot summer, air conditioning, Wi-Fi, watermelon, you can enjoy the cozy life.

When it comes to Wi-Fi, almost everyone has a wireless router. With every home having multiple devices (computers, phones, pads, etc.) connected to the Internet, the home wireless router is indispensable. In fact, for data to be transmitted over a wide area network, the carrier-grade routers used by carriers mentioned earlier are also necessary.

Wireless router is like the combination of wireless AP and broadband router. It not only has the wireless coverage function of wireless AP, but also can realize all functions of broadband router, realize Internet connection sharing in home network, and realize wireless shared access based on xDSL, PON network or cell broadband access.

Wireless router integrates router function, firewall function, bandwidth management function, integrated broadband Ethernet WAN interface, and built-in multiple 10/100/1000Mbps interface and 2.4ghz or 5GHz wireless frequency band, providing both wired access and wireless access mode, not only can be used in the home. It can also be used in offices, enterprises and other occasions.

If the wireless router is a well-known martial arts master, the telecom level router is a deep "sweeping monk", it lives in each major telecom machine room, in addition to professionals occasionally see its true features, other people rarely see. Carrier-class routers are constantly advancing with The Times in the face of the demand for rapid forwarding of massive data, and both functions and performance are greatly improved.

Functionally, routers began to support MPLS on a large scale, overcoming the expensive and limited bandwidth of ATMs in wans. MPLS is independent of Layer 2 and Layer 3 protocols. It maps IP addresses into simple labels with fixed length. During data forwarding, IP packets are analyzed only at the edge of the network rather than at each hop, saving processing time.

In terms of performance, the access side interface of the router (the interface between the router and BRAS) has been upgraded to a 10G or 40G Ethernet interface. MPLS can combine the advantages of ATM and IP technology to provide high performance similar to ATM technology while keeping IP technology simple. MPLS does not limit bandwidth. The bandwidth of a wan port has been increased to 100Gbps.

In line with the development of 5G, big video /VR/AR, mobile Internet, intelligent Internet of Things and cloud computing, routers will be constantly updated. Large-capacity, high-performance, full-service router products, cluster router, virtual router and other products emerge in an endless stream. More capacity, higher performance, more flexible operation and maintenance, router, the future can be!

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