MPLS application description

As a developing technology, with the gradual maturity of standards, MPLS applications are constantly expanding to solve the existing problems of IP networks and improve the existing environment. From the current perspective, MPLS applications are mainly concentrated on the integration of IP and ATM, IP traffic engineering management, ip vpn, and the convergence of IP and light in the future.
Because different manufacturers implement different MPLS methods, some adopt ATM switches and some adopt routers, which leads to different solutions with different focuses, and the main direction and environment suitable for applications are different. However, these applications belong to the scope of MPLS theory. In practical application, we need to make a balance between the focus of different solutions and the specific application environment. We need to know that no medicine can cure all diseases.
MPLS applications must give full play to their technical characteristics. MPLS is a technology between Layer 2 and Layer 3. It closely integrates Layer 2 and Layer 3, it gives full play to the advantages of layer-2 exchange and traffic management. At the same time, it also takes into account the advantages of layer-3 routing and flexible routing. Therefore, at present, the two main applications of MPLS are implemented around these two features: one is to use MPLS to implement traffic design TE ), the other is to use MPLS to implement an IP-based VPN.
Integration of IP and ATM

How to carry the IP Service on an ATM is a problem that has plagued people for a long time. From the early multi-protocol encapsulation, to LAN simulation, from Classical IP to MPOA, we have explored the IP service carried by the ATM from different directions and perspectives, and achieved some results.
Although the "multi-protocol encapsulation" solution is simple, it does allow IP addresses and even LAN protocols such as IPX to be transmitted over the ATM over the wide area network. LAN simulation makes it unnecessary for Traditional Ethernet users to change their existing facilities, by starting the "simulation" through the lan atm edge device, we can enjoy the high-speed switch of the ATM, although it is found that the ATM is not the fastest backbone technology of the LAN. Compared with LAN simulation, Classical IP does not establish a ing from IP address to ATM address through a series of complex server interaction processes. Instead, Classical IP is directly and concisely adopted, although theoretically not gorgeous, however, the very practical ARP Server method solves this problem and makes edge ing more efficient.
MPOA can be said to be the theoretical "peak" for carrying IP services through an ATM in a LAN. Although it was found later that this peak was at least not fully realized at present.
MPLS appears. MPLS can certainly be used in LAN to solve the problem of convergence between ATM and IP addresses. However, with the popularization of Gigabit Ethernet technology in LAN backbone networks, ATM is rarely used in backbone networks.
Therefore, MPLS is more applied to the WAN environment than the LAN, and the bandwidth resources of the Wan are much more precious than that of the LAN. MPLS absorbs the advantages of the preceding ATM bearer IP solutions, as shown in the following table.
In addition to absorbing the advantages of several technologies, MPLS also overcomes the common low-efficiency problems of several solutions and achieves the goal of carrying IP addresses in ATM simply and efficiently. At present, MPLS has been gradually applied to the operator's network and is playing an increasingly important role.
IP Traffic Management
IP traffic management is a top priority among the main applications of MPLS. As we all know, IP traffic lacks predictability and manageability. It is crucial to control and manage a business flow that occupies more than 80% of the network of an operator. The Application of MPLS solves this problem. It is particularly important that MPLS can solve this problem on the existing infrastructure.
IP VPN

Ip vpn is another main application of MPLS. MPLS labeling not only improves the efficiency of IP packet forwarding on intermediate nodes, but also serves as a part of the security role. Therefore, IETF proposed RFC 2547. RFC 2547 creatively uses BGP to transmit member information and establish Member relationships. At the same time, the route tables of each enterprise are separated by routing indexes at the edge of the MPLS domain to increase their security; at the core of the network, the router identifies the location of the next node by marking. Therefore, even if data packets are intercepted by tracking or other methods, more information about the network cannot be learned by marking. All of the above measures ensure network security to some extent.
Fusion of IP and light
In recent years, the development of optical communication has been another wave in the IT field following computers and networks. The development of data services provides the market and sufficient reasons for the rapid development of optical communication. It cannot be ignored that data services have occupied the absolute advantage of the operator's network as early as a few years ago, and are still increasing at an astonishing rate every year. On the contrary, traditional voice services are basically saturated. Therefore, the obvious conclusion is that the main driving force of optical communication will not come from traditional services such as voice, but from data services.
On the other hand, major breakthroughs in optical communication technology also provide a powerful guarantee for the development of data services. In the past, we could only transfer 622 Mbps, 2.5 Gbps, or even 10 Gbps bandwidth to a pair of optical fibers, and now we can run Gbps services. This is a miracle and a pioneering work. It provides a wide range of expansion space for data businesses. At the same time, the dense wavelength division multiplexing system is also adopted in man for data business considerations. Looking at our current man structure, this is not hard to understand. The current man takes 3 ~ Five nodes are used as the core and are connected in a mesh or part of the mesh. Generally, the POS interface of GB is used. Even if three nodes are used, each node requires two Gbps interfaces. Can existing SDH devices be provided? However, the Dense Wavelength Division System of man can easily split several Gbps waves for users without additional optical fiber cables. This is more important for emerging carriers because they do not have their own Metro transmission networks. In this way, emerging operators can directly establish a powerful Metro optical transmission network integrating voice and data.
The rapid development of data services and optical communication forces people to consider how to enable more effective and intelligent transmission of 80% of Services hosted on the optical physical layer. This initiative makes the two sides irrelevant, or the direction of independent development gradually come together.
Currently, more than 80% of data services are based on IP addresses. Especially in China, this number is not enough to indicate the importance of the IP service. About 95% of data services are developed based on IP addresses. Therefore, we need to consider how to carry the IP service on the optical physical layer, that is, the optical physical layer should be more "intelligent" on the IP ".
There have been two different opinions on this issue: one is to redevelop a set of protocols as signaling between two layers; the other is to use existing MPLS as signaling, MPLS is obviously more attractive.