A Research on MPLS―Based Transition Technology of Next―Generation Internet

Abstract. With the continuous advancement of Internet technology， Internet is penetrating to various sectors of the society and every corner of life， which spawned a variety of needs. Therefore， the development of the Internet should always meet the needs of customers. How the next generation of the Internet will develop？ How the technology will get the breakthrough？ How to use MPLS technology to make the transition of the Internet more practical and more scientific？ And so on. These questions need network technical staff give full play of the technical expertise to promote Internet technology continues moving forward. This paper first introduces MPLS technology， and then analyzes the overall architecture of the next generation Internet and the service quality required by the next generation Internet， and at last study how to make the MPLS-based transition technology of next-generation more perfect.

Key words： Next Generation Network； Quality of Service； MPLS Technology； Integration Services； Multi-Label Protocol Switching

1. Introduction

Network technology is rapidly developing. Along with the opening of the core network of China’s Next Generation Internet （CNGI）， the MPLS-based IPv4 will eventually be gradually replaced by IPv6. IPv6 is more adaptive to the new challenges， and will reflect more efficient superiority for relatively low-level IPv4 in areas such as the operation and management， uptime， control operation， computational processing of the network. With the goal to make the transition from MPLS technology to IPv6 smoother， the understanding of MPLS technology is particularly important.

2. Introduction of the basic technology of MPLS

2.1 Basic introductions and concepts of MPLS

MPLS is short for Multiprotocol Label Switching. The technology is to improve forwarding speed at the very beginning， that its origin is IPv4 （Internet Protocol version 4）. This technique has been applied in a variety of network protocols， such as Internet Protocol version 6 （IPv6）， Internet Packet Exchange （IPX）， Connectionless Network Protocol （CLNP） and other Internet technologies. Since the network computing technology that MPLS involved in are very extensive， the new demands of the next generation network technology will be met as much as possible.

The basic concept of MPLS technology can be divided into following seven parts.

Classified forwarding technology is a technology that can put methods that forward and process in the same way into a class （FEC）.

Identification meaningful label is a fixed length short identifier that can indicate the FEC category. Tags generally have four bytes and four domains， as shown in figure 1：

Fig.1. Label structure

Label encapsulated location in the packet as shown below：

LSR （Label Switching Router） is the basic elements of the MPLS network technology， and all label switching routers support multi-protocol label switching technology.

LSP （Label Switched Path）， this path is the path forwarding equivalence class in MPLS networks.

LDP （Label Distribution Protocol）， with similar functionality to traditional network signaling protocol control protocol.

LPS tunnel is also used very widely in MPLS networks.

Multilayer label stack， as the name implies， the packet to be sent will produce more than one label in the transmission of multiple LPS tunnel， gather them to form a stack， this is called the label stack. The transfer of information which will be carried out in the pattern of stack transferring.

2.2 Architecture of MPLS

MPLS architecture can be divided into network structure and node structure. Its structural model， respectively， as shown below：

The figure shows the MPLS network structure， and the basic workflow of MPLS.

As shown above， the MPLS node structure can be divided into two parts， namely the role of co-ordinating control plane （Control Plane） and passed and forwarded the information to the next stage of the forwarding plane （Forwarding Plane）.

3. Overall framework and demand of the next generation of the internet

3.1 The overall architecture of the next-generation network Next Generation Network （NGN） is an open network architecture system to provide different services according to the needs of different users. According to the requirements of the growing network speed and quality， the next generation network uses more advanced technology， via a high-speed public transport links and routers， Softswitch as the core Softswitch service control functions and network resource control function， audio， image and data can meet user requirements for safe， high-quality transmission of the multi-service network. At this point， it is independent of the transmission network. And through these two functions， it can be all the business of the existing circuit switches available to the user. Then the next generation network provides different functions for the user according to the need.

According to the actual needs of the network technology， the next generation network will have packet role， that it is a packet network. This network is separated from the transmission network. In addition， the next-generation network will also separate the call control and service provider as well as the underlying transport. The next generation network will provide a wide variety of functions to users， giving them a quick and convenient network experience.

The high-speed routers and multi-protocol label switching （MPLS） technology are the keys to meet the next generation network. High-speed routers and multi-protocol label switching technologies complement each other， since high-speed routers can transfer large-capacity information， but the quality of communication services still relies on multi-protocol label switching technology （MPLS）. The multi-protocol label switching technology is an advanced technology. It can not only solve the problems of network technology， but also provide more new features for the next generation network （NGN） as technology advancing and maturing. It can be seen that the Multiprotocol Label Switching （MPLS） technology plays a particularly important role in the next generation network.

The next generation network has been widely developed and used. Speed broadband has been the basic requirements for the user to use of the Internet. Next generation network for broadband access by various methods， such as high-speed digital subscriber line （VDSL）， fiber to the home （FTTH， i.e. having a transmission speed， the transmission capacity and the transmission distance is long， etc. The optical fiber transmission medium has access thousands of families. Then the next generation network will naturally use optical fiber as the transmission medium）， free space optics （FSO） and wireless local area network （WLAN）. These access methods provide a more convenient transmission environment for the next generation network （NGN）.

3.2 The main demands of the next-generation networks

The mobile network supplier is the most important part the Internet relies on in the development and application. No matter telecommunications or mobile， their ultimate purpose is to provide customers with multimedia services to fit the needs of the times， rather than the traditional single voice services. So， as the demand side expanding， the next generation network will face multiple challenges. In addition to enhance the technical level， major carriers also need to grasp how making the next generation of network technology fit users’ need to level more， which is important here includes not only technical， but also the quality of service.

The huge user needs bring broad market for network operators， providing a broad space and the possibility for the development of next-generation networks. The developed 3G networks and later 3G mobile communications system to provide temporary protection for multimedia needs of the user. More advanced 3G network mode transmits more efficient， and its high capacity and high speed and flexibility have been recognized by the majority of users. Network mode converter produces a new business model， the Internet Protocol version6 （IPv6） developed from the Internet version 4 （IPv4） became the basic guidelines of the 3G network. So how to use MPLS technology to ensure reasonably safe transition to the next generation of Internet-based the IPv6 version will be an obvious problem facing by network technicians.

In addition to the requirements of the next generation of Internet technology at the technical level， the security of the Internet is also very important. Original， such as firewalls， security filtering， access control， data encryption and other means cannot fully guarantee the safety of the existing information. New information security protection measures are urgently needed. Such as the protection of key sites and data centers， real-time and comprehensive understanding of the entire network conditions to ensure that the contents of the network are more standardized， and so on. Regardless of the source of information transfer， on the way， or ends should ensure information security.

4. research on mpls-based transition technology of next-generation internet

According to the requirements of the next generation of network technology， the Internet version 4 （IPv4） will eventually upgrade to the Internet version 6 （IPv6）， the version conversion process essential to rely on multi-protocol label switching technology （MPLS）. IPv4 is now a mainstream network. Transition from IPv4 to IPv6 is not done overnight， it is a gradual process， so this shift is a long-term process. The diversity of modern network technology allows transition to IPv6 to have a variety of ways. MPLS technology network transmission technology focused on a single platform so will reduce the complexity of conversion， and the technology can also be compatible with the existing network， so in the Transition from IPv4 to IPv6， the MPLS technology is regarded as a more reliable the transitional technology.

Transition from IPv4 to IPv6 has a variety of ways to use MPLS technology， of which the most commonly used are following four kinds. They are CE router configuration IPv6 tunnel， MPLS circuit pass-through IPv6， IPv6 on the PE router and the Native IPv6 using MPLS technology.

First of all CE routers uses MPLS transition technology to establish IPv6 tunnel is the most simple and convenient way. This technique relies on IPv4 to establish an IPv6 packet through the tunnel to get Internet interoperability， which can be composed to form a router. After encoding translation during the conversion from IPv4 to IPv6， it can be automatically created， so reduce unnecessary overhead. Thus this is simpler to do conversion of existing MPLS network.

Second is MPLS circuit transparent transmission of IPv6. IPv6 over MPLS has specialized information delivery channel dedicated connection. In this link IPv6 fully grasp various mechanisms within the system， in addition， when in the communication it does not affect the original MPLS network. But the transition is in some proprietary vendors will be achieved， so this way has some limitations.

Third is the PE router using IPv6. This way can reduce the impact of network operators， thereby reducing the impact on the data in the existing IPv4. The PE router using the IPv6 requires the PE router upgrading to IPv6 and running on the network interface to connect the core MPLS. In this method， the complex technical requirements bring great challenge to researchers.

The last one is Native IPv6 MPLS of which the core technology is to upgrade the MPLS core network of IPv4 to IPv6. This upgrading is more complicated， and requires more comprehensive technical services， and more factors need consideration in the actual conversion. This upgrade involved a comprehensive upgrade， which is based on the ultimate goal of MPLS technology IPv4 to IPv6 transition.

How to choose？ It requires constant contrasting and researching. The factors to be considered in the program selection process should have all factors fully involved， such as the size of the traffic capacity of the information， and the most important economic prospects. IPv4 to IPv6 transition based on MPLS technology is a gradual process， and each period have their own characteristics， so the method taken in different times will be different. No matter what kind of technologies we choose， the goal we are pursuing is the same.

From the four technologies difficulty degree of complexity and transition comprehensive view， we can divide transition into three steps. The first step is to configure IPv6 tunnel on CE routers and pass through IPv6 on the circuit of MPLS， the second step is to use IPv6 on PE router， and the last is to fully transit the existing network to IPv6 using the Native IPv6 MPLS technology.

All in all， there is a long way to go to achieve transition to the next generation Internet， for which technical staff will keep on going exploration and breakthrough. The next generation of Internet technology not only requires higher technic， but also the economy. The major network vendors in the market compete in the ongoing operational restructuring， using the latest operating strategy， the ultimate goal of these measures is to occupy a higher market share， and to achieve maximum benefits. The key here is to master the key technology of the next generation network upgrading. The present era is the era of technology， and mastering of science and technology is necessary for the major network vendors to keep in an invincible position.

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