Saving OPEX with Sophisticated End-to-End Service Management

Microwave transmission equipment is widely used in mobile backhaul networks because it is simple, flexible, reliable, and easy to deploy. However, end-to-end (E2E) management of microwave transmission equipment based on Ethernet, PDH and SDH is difficult. This results in low efficiency in service deployment and troubleshooting. Because there are thousands of network elements (NEs) on a mobile backhaul network, efficient service management is difficult. The main inefficiencies are in

• service deployment. Service provisioning is time-consuming and laborious. An OAM staff member needs to configure all NEs for the network, and any error in the configuration can lead to service failure.
• network maintenance. The network is maintained by a professional OAM staff member. Maintenance work involves service adjustment, performance monitoring, and network expansion. Without a special service management tool, network performance analysis is also time-consuming and laborious.
• fault location. In the event of service failure, an OAM staff member must access NEs (through which services are carried) one by one to locate the fault.

As early as 2001, the Metro Ethernet Forum (MEF) found that the existing transport network could barely support future service development. It therefore put forward the concept of carrier-class Ethernet. Carrier-class Ethernet equipment is required to provide complete service management, including network monitoring and diagnosis, and fast service provisioning. E2E service management is a prerequisite for microwave transmission equipment to meet the requirement of carrier-class operation.

ZTE NR8000 series microwave products provide hybrid TDM/packet and enhanced Ethernet-based all-IP transmission as well as professional E2E service management, troubleshooting, and QoS management tools. These products can significantly improve OAM efficiency, address carrier-class requirements, reduce opex, and maximize profits for telecom operators.

Ethernet Service Management Model

MEF6.1 defines three service types: point-to-point, multipoint-to-multipoint, and rooted multipoint Ethernet. These are important indicators for service provisioning capabilities of carrier-class Ethernet equipment. Based on MEF6.1, MEF10.2 specifies an Ethernet service management model from the user perspective and puts forward the concept of Ethernet virtual connection (EVC). EVC can be considered as a mapping of user traffic into carrier-class Ethernet flows.

MEF6.1 and MEF10.2 provide standard references for Ethernet service management. ZTE NR8000 series microwave products are based on these standards and are used to set up an Ethernet service management model and provide standard management interfaces. This makes service expansion and management easy, reduces opex, and increases profits for operators.

MEF10.2 focuses only on service access point and not on service transmission path. A QinQ link is introduced to address the issue of transmission paths on the network. A QinQ link is built on the basis of independent VLAN MAC address learning and forwarding. It is a bidirectional E2E service transmission path identified by S-VLAN ID.

The ultimate objective of suppliers and operators is to provide users with differentiated service that can effectively increase operator ARPU. ZTE NR8000 series microwave products support differentiated service, traffic-based classification mark (TCM), and per-hop behavior (PHB). They also integrate service configuration and QoS to manage and monitor networkwide QoS policies.

A hierarchical Ethernet service management model is shown in Fig. 1. The original user service is at the top layer; user service adaptation is at the middle layer; and QinQ link at the bottom layer to solve the problem of transmission paths on the network. Advantages of the hierarchical management are clear structure, well-defined responsibilities, and easy maintenance.

End-to-End Ethernet Service Management

The Ethernet service management model supports end-to-end service provisioning, modification and deletion. It also provides the guided configuration. An Ethernet service can be quickly established in four steps.

Step 1 Build a service frame and specify service source/destination and service type.

Step 2 Access user service, configure a mapping from user traffic to Ethernet service, classify traffic flow, limit access rate, and create a mapping from user priority to network priority.

Step 3 Configure a QinQ link. The path can be manually specified by the user or automatically generated by the NMS.

Step 4 Implement OAM (optional) to monitor service status.

After a service is configured, an operator can preview configuration information and select whether to activate the service. When the service configuration is applied, the operator can look over NE configuration and service running status in real time via the NMS and can modify or delete the service in an end-to-end manner.

E2E TDM Service Management

ZTE NR8000 series microwave products support the transmission of TDM services in native and simulated modes.

• native TDM service management. An operator selects timeslots at the source and destination ports and specifies an intermediate node. The NMS automatically sets up a cross connection of the intermediate node and quickly provides a TDM path.
• simulated TDM service management. TDM services at the network ingress are simulated to Ethernet frames and are regenerated and restored back to original TDM services at the network egress. The module that implements simulation and de-simulation is called the interworking function (IWF) module. Configuration of the simulated TDM services can be divided into IWF configuration and Ethernet configuration. The IWF configuration includes timeslots at the service source and destination ports, and alarm threshold. The Ethernet configuration is the same as that of E2E Ethernet service management.

E2E Network-Wide Service Management

Because of restrictions on transmission bandwidth and line-of-sight transmission, microwave transmission equipment is usually applied at the access side, and optical transmission equipment is used for convergence. Differences in equipment and technology inevitably result in difficult E2E service management. When two kinds of equipment are supplied by different vendors, service management is even more difficult. To address the issue of service management for hybrid optical and microwave networking, ZTE has developed the solution for managing E2E network services at two phases.

Phase 1 Segmented E2E management. E2E management is implemented for microwave and optical transmission. Segmented E2E management is simple because it does not consider the issue of equipment interoperation. ZTE provides complete OAM functions that can implement seamless service monitoring throughout the network.

Phase 2 E2E network-wide management. Both optical and microwave transmission equipment provides standard carrier-class Ethernet services. They are interconnected through the MEF26.1 E-NNI port. MEF26.1 defines a standard management interface E-NNI and management parameters. Any equipment that supports this standard is interoperable regardless of whether they are from the same vendor.

Conclusion

ZTE's E2E microwave service management solution integrates service configuration, management, troubleshooting, and QoS management. The solution can enhance service configuration and management efficiency while reducing the probability of errors. It can also be combined with ZTE’s optical transmission system to provide E2E network-wide service management and can significantly save opex for operators.