subject: photo] Of Intelligent Optical Network And The Integration Of Traditional Transmission Networks [print this page] Summary This article describes the ASON and Wangjiantongxin for inter-domain interface, and made ASON network and the traditional hybrid network and the SDH transmission network to achieve interoperability solutions.
With the intelligent optical network (ASON) the gradual application of transmission network will gradually increase the intelligent network element equipment. As traditional carriers have invested heavily in SDH networks, in order to protect the original investment, to achieve the traditional optical transport networks to ASON smooth evolution of the traditional equipment, intelligent network elements and is bound to coexist for a long period of time between the two interoperability is inevitable, therefore, ASON and traditional SDH network interoperability and integration of ASON building will be a key factor in the decision.
1, ASON interface ITU-T for ASON standards that define the user network interface (UNI), Network Node Interface (NNI), Connection Control Interface (CCI), network management interface (NMI). On the impact of new and old network convergence is mainly UNI and NNI. Shown in Figure 1.
Figure 1 1.1 The User Network Interface (UNI)
UNI is the core optical network and its customers equipment (edge electronic equipment) between the optical interface is an important symbol overlapping network model is different domains, signaling interfaces between the different levels. Through this interface, you can achieve optical network connectivity and electrical devices, electrical devices can dynamically access, revoke, modify certain characteristics of the optical bandwidth. Usually in the basic message of this interface should include call control, resource discovery, connection control and connection options.
UNI does not support the routing function. Completed their main tasks are: to establish the connection, the connection removal, state information exchange, auto-discovery and realization of user services delivery. The current industry standard protocol in the most well developed and mature is 0IF the UNI protocol, which not only developed a set of practical UNI signaling protocol (RSVP or LDP), control channel to achieve (with the road signaling, with the way non- signaling and associate with the road signaling) and maintenance, and the corresponding frame packaging standard, but also provides a mechanism for service discovery and topology discovery.
1.2 Network Node Interface (NNI)
NNI for the mutual exchange of information within the control layer. In order to avoid exposure to sub-network internal information to external untrusted subnet, NNI is divided into two types, namely, the internal network node interfaces (I-NNI) and external network node interface (E-NNI). I-NNI is within the same network or the network control layer entity and credibility of the communication network interface for unified management within the Department of 0CS achieve mutual communication. E-NNI is the network and external network control layer between the two-way signaling interface, network and physical control of the external untrusted network layer communication interface. This usually occurs between networks of different operators on the Internet. E-NNI interface signal will be screened within the network topology and other information, the delivery of key information, including call control, resource discovery, connection control, connection options and connection routing. Through this interface, signaling, ASON can be divided into several sub-network management domain, E-NNI can be achieved between these fields end to end connection control.
2, ASON and traditional optical network interoperability
ASON UNI and NNI in two ways by the traditional optical network interoperability.
2.1 by UNI with the traditional optical network interoperability
Figure 2 shows the optical network through the UNI to communicate with the traditional, the figure AS1, AS2, said the traditional optical network, CMS connection management system.
Figure 2 In this way, the traditional optical network signals as ASON client access, which is characterized by: A) can take advantage of existing network resources. B) as a traditional optical network ASON clients, UNI agent network system connection requests sent to the ASON, the ASON complete the connection establishment. This model is suitable for metropolitan area and the existing relationship between the new ASON backbone. C) the current implementation is the traditional one-way UNI-C Optical Networks approach is traditional ASON optical network as a customer. D) transmission network, after the internal use of UNI, UNI can not use user-oriented. That is not directly supported by the soft client to connect (SC) operations. E) with the UNI interface feature is only focused on data equipment, has not really integrated in the transmission network (such as SDH equipment). 2.2 by NNI interoperability with traditional optical network Figure 3 shows the agent through the NNI to communicate with traditional optical network. In this way, by traditional optical network settings NNI agents, to achieve band distributed ASON. Figure 3 This approach is characterized by: A) conventional optical network through the NNI NNI Agent to function. NNI interface can provide more network information, such as routing information and protection of the recovery information. B) NNI interconnect interconnected than UNI way closer to the true meaning of ASON, to achieve more functionality. Each NNI agent may represent one or more node devices. C) NNI agent of a node or a network, can provide SC services. D) For those who can not upgrade or modification of existing networks, can be used in the transport layer directly connected way. E) ASON and existing network management and configuration, respectively, which is more than the current Internet the same way manufacturers can not achieve the unity of the whole network management and scheduling. photo] Of Intelligent Optical Network And The Integration Of Traditional Transmission NetworksBy: sisi
