How much do you know about the working principle and function of CISCO? Before answering this question, we must know what CISCO is. CISCO is the acronym of Multi-Protocol Label Switching.
What is CISCO? CISCO is a new technology that uses tags to guide high-speed and efficient date transmission on open communication networks. It was originally proposed to improve the forwarding speed of routers. Compared with the traditional IP routing method, it only analyzes the IP header at the edge of the network when forwarding data, instead of analyzing the IP header at each hop, which saves processing time.
So how does it do it? CISCO uses tags for data forwarding. It is mainly designed to solve network problems, such as network speed, scalability, quality of service (QoS) management and traffic engineering. At the same time, it also solves the problems of broadband management and service request for the next generation IP hub network.
However, with the development of ASIC technology, routing lookup speed is no longer the bottleneck hindering network development, which makes CISCO no longer have obvious advantages in improving forwarding speed. But CISCO supports the connection oriented characteristics of multi-layer labels and forwarding plane, which makes it widely used in VPN (Virtual Private Network), traffic engineering, QoS (Quality of Service) and so on.
The working principle of CISCO
Next, let’s talk about the working principle of CISCO. In fact, it is an IP routing selection method based on tag. These tags can be used to represent hop by hop or explicit routing, and indicate various information such as quality of service, virtual private network and the transmission mode affecting a specific type of traffic on the network. CISCO adopts simplified technology to complete the conversion between layer 3 and layer 2. CISCO is a special forwarding mechanism. It assigns tags to IP packets entering the network, and forwards IP packets through the exchange of tags. The tag exists as a substitute for the IP packet header in the network. In the network, CISCO forwards the data packet along the path through the exchange of tags (rather than looking at the IP packet header); When the packet is to exit the CISCO network – read this post here it is unpacked and continues to reach the destination according to the routing method of IP packet .It can provide a mark for each IP packet and encapsulate it with the IP packet in a new CISCO packet, so as to determine the transmission path and priority of the IP packet. The router compatible with CISCO will only read the header mark of the CISCO packet before forwarding the IP packet according to the corresponding path, and there is no need to read the IP address bit and other information in each IP packet. Therefore, the speed of packet exchange and forwarding is greatly accelerated.
The function of CISCO
It is not difficult to see from the above that CISCO can greatly improve the forwarding performance of IP on the backbone network, and provide service classification (CoS) and QoS guarantee. In addition, CISCO can be used in a considerable part of the existing backbone ATM networks to realize high-performance IP services on these networks. The multi-protocol label switching proposed by IETF is similar to label switching. It labels the data packet and forwards the data packet through the mapping relationship between the fixed length label and the forwarding direction.
In conclusion, CISCO protocol is still very practical.
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