Hello guys, I'm going to introduce you the segment routing in this post, hope you like it.
The development of cloud computing poses new challenges to the WAN, requiring changes in the traditional WAN. SD-WAN, as the core technology for reconstructing the WAN, accelerates network delivery and optimizes applications through automatic deployment, centralized control, intelligent scheduling, and visualization, improve bandwidth utilization, simplify network operation and maintenance, and meet the needs of cloud computing for WANs.
Intelligent scheduling is a key capability of the new-generation WAN. It is very important to guarantee application quality and optimize bandwidth resources. Existing traffic engineering technologies such as MPLS and RSVP-TE can meet the application's differentiated guarantee requirements for bandwidth, but there are problems such as multiple types of protocols, complex deployment, difficult management, and poor scalability, which cannot meet the dynamic requirements of the new generation of WAN Requirements for deployment, flexible scheduling, fast, and scalability. Therefore, a new protocol, Segment Routing, has emerged, which not only inherits the advantages of MPLS technology, but also can adapt to the future development of IPv6, SDN and other technologies. SD-WAN network provides a flexible and efficient control method. It has the characteristics of simple use and easy expansion. It can better implement traffic scheduling and path optimization, provide application-driven network services, guarantee the quality of key services, balance traffic distribution, and improve. Leased line utilization, reducing line costs.
Segment Routing is a source routing protocol, also known as segment routing protocol. The source node specifies the path for the application message, and converts the path into an ordered segment list and encapsulates it into the packet header. The intermediate nodes of the path only need to forward according to the path specified in the packet header. Segment is any instruction that guides the device to process messages, such as forwarding the message to the destination according to the shortest path, forwarding the message through the specified interface, and forwarding the message to the specified application / service instance.
Segment Routing has many incomparable advantages due to its simple, efficient, and easily expandable characteristics:
1. The protocol designed for the SDN architecture combines the advantages of autonomous device forwarding and centralized programming control to better implement application-driven networks. At the same time, it can naturally support traditional networks and SDN networks and is compatible with existing equipment to ensure smooth network evolution.
2. Simplify the device control plane, reduce the number of routing protocols, simplify operation and maintenance management, and reduce operating costs; label forwarding tables are simple, easy to expand, and small in size. The number of forwarding tables maintained on a device is N (the number of node labels, Generally the number of nodes in the entire network) + A (adjacent label data, generally the number of device interfaces), while the traditional MPLS network is N ^ 2.
3. Support a wide range of deployment scenarios, including backbone networks, DCI networks, and DC networks, and support both MPLS and IPv6 networks.
4. Can implement TE, FRR, OAM and other functions in a simpler way, thereby simplifying network design and management, quickly obtaining network services, and optimizing the performance of the entire network.
Also, you can find the video version at (video) New IP Technology Series MOOC-Segment Routing
In the next chapter, we'll introduce you the segment routing briefly forwarding process.
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