Optical fiber communication technology and Prospects
Summary Number of optical fiber communication technology hot spots, the latest trends and prospects are briefly summarized. Made the following main points: carrier-class Optical Ethernet technology has been increasingly necessary with the required public telecom network functionality and performance, as an important future direction of MAN; 40Gbit / s system technology has become mature. But the time needed large-scale application; coarse WDM metropolitan area in China has good prospects for development; the next generation ROADM metro areas of the application being extended; point to point WDM transmission will move toward dynamic networking; EPON and GPON FTTH technology will dominate. But large-scale application also needs to address the cost of supporting technologies and applications.
Experienced many years of silence foam and fiber optical communication in the first half of 2006 has shown a good momentum of development. Continued growth in mobile services, SMS services in full swing, peer communication (P2P) business growth, IP television (IPTV) business poised to take off, which makes the bandwidth demand continues to grow. Annual growth rate of world demand for network bandwidth is still as high as 50% to 100%, and our route traffic over the past few years and more than 200% annual growth rate of the bandwidth demand. The operational level of the development trend is not only based on the telecommunication network?? Optical communication raised new capacity requirements, but also in function and performance has also put forward new demands.
1, carrier-grade Optical Ethernet New Development
Recently, carrier-grade Ethernet developed rapidly, some of the latest technical solutions already have a hard QoS and carrier-grade network management capabilities, to provide 50ms protection switching time. In addition to the expansion and enhancement of traditional Ethernet technologies, such as Q inQ and enhancement technology?? Ethernet Ring Protection (Ethernet Ring ProtocolERP) technology, the standardization organizations and manufacturers to develop a number of new metro technologies such as RPR (ResilientPacket Ring, RPR), MSR (Multiple ServicesRing, multi-service ring), MAC in MAC encapsulation, PBT (Provider BackboneTransport, backbone transmission network provider) technology, VPLS (Virtual Private LANService, Virtual Private LAN Service) and so on. The following brief MAC inMAC package, PBT and three mainstream VPLS Metro Ethernet technology.
1.1 MAC in MAC encapsulation technology
MAC in MAC encapsulation technology is based on IEEE802.1ah standards, and its basic idea is the user's Ethernet frame and then package a carrier Ethernet frame header, the formation of two MAC addresses. This will bring the following benefits:
(1) can completely shield the user side of information to isolate the core network and reduce the user MAC address forwarding on the pressure of the core network, solve network security problems.
(2) has a clear hierarchical structure. In the domain of the MAC frame header carrier with 24bit business label, in theory, can support 16 million users, a fundamental solution to network expansion and expansion problems.
(3) operating network and user network isolation, avoiding the user network broadcast storms that may occur and potential forwarding loop problem, the network is robust.
(4) operators without worrying about the operating network VLAN and MAC address conflict with the user network, simplifying network planning and operations.
(5) MAC in MAC layer packaging technology used, without complex signaling mechanism.
(6) operating network Ethernet switch only to learn their MAC addresses, thereby reducing storage and processing needs, so that equipment, such as network construction and operation and maintenance costs.
1.2 PBT technology The MAC inMAC package, based on only a small amount of change, turn off some of the Ethernet, using existing Ethernet hardware forwarding can provide new features, will have no Ethernet connection connection-oriented transformation of the two-story tunnel technology to provide a hard QoS and carrier-grade performance dedicated Ethernet link, which is the so-called PBT technology. PBT technology, the main features are as follows:
(1) good scalability. Turn off the MAC learning function, can eliminate the cause flooding and MAC broadcast network size limit function. In addition, PBT with VID + MAC address as a global unique address and destination address-based forwarding, VID does not express the traditional loop-free domain, but to identify some specific channels, does not have the world's only, thus eliminating the expansion restrictions, the network has an almost unlimited number of tunnels