Huawei SDH Transmission Equipment Optix OSN3500 Optical Transmitter Technology is highly regarded in existing metropolitan transmission networks, has been applied on a large scale, and is about to be released as an industry standard in the industry. Compared with other technologies, its technical advantages are: solving the problem of low efficiency of SDH technology in carrying data services; solving the problem of low efficiency and high cost of ATM/IP in carrying TDM services; solving the problem of low IP QoS; solving the problem of network limitation of RPR technology, realizing double protection, and improving the service security factor; enhancing the concept of network for data services, and improving the monitoring and maintenance capability of the network; and reducing the service selection and maintenance capability. Enhance the network concept of data service, improve the network monitoring and maintenance capability; reduce the risk of service selection; realize the advantages of network formation with lower investment, unified network construction and on-demand construction; and adapt to the demand of full-service competition and provide services quickly.

MSTP enables the transmission network to develop from a supporting network to a bandwidth operation network with independent operation value, utilizing its own mature technical advantages to provide high-quality and low-priced bandwidth resources to meet the demand for bandwidth in the urban area. Due to its multi-service characteristics, the metropolitan transmission network constructed with B-ADM equipment can provide a rich variety of bandwidth services according to the requirements of users. B-ADM equipment under the MSTP technology system integrates operational concepts and intelligent features into the network scheduling, equipment, and other aspects to realize the convenient and fast establishment of services, thus further guaranteeing the implementability of the bandwidth operation to meet the market demand for metro transmission network.

I. Typical Routerless Networking

Optix OSN1500_OSN2500_OSN3500 equipments support the construction of a network that carries both TDM and packet services without a router, realizing the interoperability of TDM services and packet services between base stations and RNCs.

A typical network is shown in Figure 1.

Figure 1 Typical Networking Diagram without Router

As shown in Figure 1, NE1 and NE2 are usually OptiX OSN 1500 or OptiX OSN 500/550 devices; NE3/NE4/NE5/NE6 are usually Optix OSN1500_OSN2500_OSN3500 devices; NE7/NE8 are usually OptiX OSN 7500/7500 II devices.

At the access layer, FE services from the base station are aggregated to the packet GE ring at the access layer through NE1 and NE2 respectively, and then successively aggregated to the packet ring of 10GE through NE3 and NE6, and finally the services are transmitted to the RNC.

Mixed Networking with Routers

In the packet domain, OptiX OSN equipment can be used to deploy Layer 2 network, and then connected to the RNC side through the router, which can take advantage of the strong Layer 3 processing capability of the router and improve the scalability of the network.

Service Carrier

This solution has the following two types of service bearers:

• For TDM services, SDH equipment with single homing method is used to carry them.

• For ETH+IP services, Optix OSN1500_OSN2500_OSN3500 adopts L2VPN in the network, and IP forwarding or L3VPN in the CX network.

  Optix OSN1500_OSN2500_OSN3500 networks use E-Line or E-LAN service delivery, interfacing with CX equipment through Native ETH, and CX equipment terminates Layer 3 delivery on Layer 2 VLAN.

Introduction to Networking

Mixed networking with routers is flexible, with various choices of equipment types at each level:

• The access layer equipment adopts OptiX OSN 1500, OptiX OSN 500, or OptiX OSN 550.

• OptiX OSN 580, OptiX OSN 3500, OptiX OSN 7500 or OptiX OSN 7500 II for the aggregation layer.

• Core layer devices use OptiX OSN 7500, OptiX OSN 7500 II, or CX 600.

The common types of networking are:

• Triangular Networking

  A typical triangular network is shown in Figure 1. Under this network, MPLS Tunnel/PW APS is enabled between the Optix OSN1500_OSN2500_OSN3500 access devices and aggregation devices, and the OptiX OSN devices and the CX devices use LAG and E-T runk docking to collaborate in protecting the intermediate links, respectively.

  Figure 1 Triangular Networking

  

  
  

• Zigzag Networking

  A typical zigzag network is shown in Figure 2. Under this network, the OptiX OSN equipment accessed by the base station is configured with the same-source and different-host MPLS Tunnel/PW APS, and the primary and backup Tunnel/PWs are terminated on the two OptiX OSN equipments docked with the CX equipment. The Optix OSN1500_OSN2500_OSN3500 devices connected to the CX device use E-LAN to protect the link and the device with the VRRP of the CX device. The devices at the aggregation layer realize dual homing, which can well reduce the risks caused by equipment failures at the aggregation layer and the core layer.

  Figure 2 Zigzag Networking

  

III. Traversing Third-Party Layer 2 Networks

Optix OSN1500_OSN2500_OSN3500 devices support adding different VLAN tags to different MPLS Tunnel, which can realize traversing third-party Layer 2 networks in the packet domain.

The typical network configuration is shown in Figure 1.

Figure 1 Typical Networking for Traversing Third-Party Layer 2 Networks

As shown in Figure 1, NE1 and NE2 are OptiX OSN 1500 devices or OptiX OSN 500/550 devices; NE3, NE4 and NE5 are usually Optix OSN1500_OSN2500_OSN3500 devices; NE3, NE4 and NE1, NE2 form a packetized GE ring on the access side, and NE3 and NE4 interface with the third party network on the network side. network side to interface with the third-party network. On the access side, FE services from the base station are accessed to the packet GE network through NE1 and NE2, respectively. after NE3 and NE4 add different VLAN labels for different MPLS Tunnel, the service data traverses the third-party Layer 2 network to the network element NE5, which carries out the label switching according to the MPLS Tunnel label and ultimately transmits the data to the RNC. similarly, the RNC passes the service to the base station, and after NE5 adds different VLAN labels according to different MPLS Tunnel labels, the data traverses the third party's Layer 2 network to NE3 and NE4, which exchange labels according to different MPLS Tunnel labels, and ultimately transmit the data to NodeB1 and NodeB2, respectively .Optix The OSN1500_OSN2500_OSN3500 devices support end-to-end configuration and management of the entire network traversing the third-party Layer 2 network.

Dual Domain Overlay Networking

OptiX OSN devices are equipped with packet features that enable them to realize packet domain-based Ethernet service networking overlay on TDM networks.

Overlaying GE ring at access layer and 10GE at aggregation/core layer

OptiX OSN devices support overlaying packet domain-based Ethernet services on existing TDM networks.

As shown in Figure 1, packet services and traditional SDH services coexist in the same network, packet services are transmitted on the packet ring, and traditional SDH services are transmitted on the TDM ring, and the two services do not interfere with each other.

With the completion of IP, Optix OSN1500_OSN2500_OSN3500 equipment can be smoothly upgraded to pure packet domain to meet the increasing demand for packet services.

Figure 1 Stacked GE ring at access layer and 10GE at aggregation/core layer

• In the above typical network, the access layer equipment is generally used OptiX OSN 1500 or OptiX OSN 500/550; the aggregation/backbone layer equipment is generally used OptiX OSN 3500/7500/7500 II.

• At the access layer, SDH services are transmitted on STM-1/STM-4 rings; packet Ethernet services are transmitted on GE rings. At backbone/aggregation layer, SDH services are transmitted on STM-16/STM-64 ring; packet Ethernet services are transmitted on 10GE ring.

• SDH services on the traditional TDM domain and Ethernet services on the packet domain are transmitted independently.

• In the TDM domain, Optix OSN1500_OSN2500_OSN3500 devices use end-to-end TDM service protection; in the packet domain, OptiX OSN devices use end-to-end Tunnel/PW protection to meet the requirement of 50ms fast handover.

Utilizing dual-domain bridging veneers with 10GE overlay at aggregation/core layer

Optix OSN1500_OSN2500_OSN3500 devices support the EOS service diversion function, which enables the access layer to utilize the TDM ring and also realize the function of direct access to Ethernet services. As shown in Figure 2.

In the case of the increasing growth of packet services, EOS service diversion function solves the obstacle of capacity expansion of traditional SDH network.

Figure 2 Using dual-domain bridging single board, aggregation/core layer stacked 10GE

• In the above typical network, OptiX OSN1500 or OptiX OSN500/550 are generally used for access layer equipment; OptiX OSN3500/7500/7500 II are generally used for aggregation/backbone layer equipment.

• As shown in Figure 2, in the access layer where the rate is STM-1/4, there is only TDM domain and no packet domain. the OptiX OSN 1500 equipment transmits E1 and FE services accessed by the base station to the OptiX OSN 3500/7500/7500 II equipment.

• At the backbone/aggregation layer, there is a packet ring with a rate of 10GE and a TDM ring with a rate of STM-16/64. The OptiX OSN 3500/7500/7500 II utilizes the dual-domain bridging single board EDQ41 to transmit the two kinds of services accessed to the TDM domain and packet domain at the aggregation/backbone layer respectively. That is, the E1 service is transmitted on the STM-16/64 ring at the aggregation/backbone layer; the FE service is transmitted on the 10GE ring at the aggregation/backbone layer, and finally the E1 service is transmitted end-to-end to the BSC equipment and the FE service is transmitted end-to-end to the RNC equipment.