Use RPR and MPLS to improve MSTP network performance

The current MSTP device uses the point-to-point circuit connection mode to support burst data services through the introduction of the green + VC-xv + LCAS and L2 switching. The network usage efficiency is not high. Only by fully introducing the RPR and MPLS technologies can MSTP networks achieve statistical reuse of network-wide data services and provide fast end-to-end VLL/VPLS services. The gangwan network is the first MSTP device that integrates MPLS switching and RPR networking capabilities in the industry. The system cross-board has built-in large-capacity MPLS switching and RPR networking capabilities, which effectively improves the efficiency of MSTP networks, it has been recognized by the Institute of transmission and the Institute of telecommunications and other authoritative departments.
Role of RPR and MPLS 
Network Efficiency Improvement 
As a basic transmission network, MSTP needs to focus on several basic features unique to the transmission network: security, transparency, and efficiency. For the traditional MSTP, the point-to-point circuit connection mode is used to support burst data services by introducing the relationship between the green + VC-xv + LCAS and L2, it only solves the problem of Ethernet port access and port convergence, and the network usage efficiency is not high. Network efficiency can be greatly improved only by introducing MPLS-based virtual connection technology to achieve statistical reuse of data services across the network and providing transparent end-to-end VPN services. In addition, by introducing the RPR Shortest Path Selection technology, the inner ring and outer ring can simultaneously transmit data services, which can improve the loop efficiency by 100% than the traditional MSP protection.
Fast end-to-end VLL/VPLS service configuration
According to the Draft ITU-TG.etnsrv, there are four types of Ethernet business in MSTP: EPL Ethernet leased line business, EVPL Ethernet virtual leased line business, EPLn Ethernet dedicated LAN business and EVPLn Ethernet virtual dedicated LAN business. Among them, the EVPL/EVPLn service is also called the VLL/VPLS service in MEF.
According to the Draft ITU-T and the draft standard of the Ministry of Information Industry, both EVPL and EVPLn in MSTP adopt MPLS technology, so that end-to-end VLL/VPLS services can be provided together with data networks using standard MPLS technology. Of course, some manufacturers will consider using the stack vlan technology or the CID of the Green Line as the Ethernet virtual connection mark. However, these two technologies have problems in terms of standardization, fast configuration of business connections, and scalability. In contrast, the use of MPLS technology to implement VLL/VPLS has become a standard practice of the MEF forum, and the signaling technology established by the LSP connection is also very mature and already in the switch, vrouters are widely used. Therefore, using MPLS Technology in MSTP to provide fast end-to-end VLL/VPLS service configuration is an inevitable choice.
Provides network protection for the MAC and MPLS layers of RPR.

Traditional mstp msp protection can only provide physical layer network protection based on network topology changes. For MSTP supporting RPR and MPLS technology, it can provide network protection based on rpr mac layer and MPLS layer.
Because the RPR protection function can only be confined to one single ring, the MPLS layer connection protection technology must be used for complex cross-ring networks. For devices that do not support MPLS switching and scheduling, the MPLS dual-node interconnection technology can be used to achieve cross-ring network protection, as shown below:
Node failures and link failures between multiple RPR loops are achieved through mpls dni technology.
In the OpCity device of the Hong Kong Bay network, because the system cross board has built-in MPLS switching and RPR networking modules, and supports the backup function of the Board device, therefore, the RPR cross-ring service scheduling can be completed through the backup of this module. The figure is as follows:
RPR and MPLS Technical Architecture Model 
For the application of RPR and MPLS Technology in MSTP, the MSTP equipment technical specifications of the Ministry of Information Industry Provide the following functional models.
Like SDH specifications, this model does not provide how to schedule MPLS connections in MSTP. We know that for EPL or EPLn businesses, as the business connection is a VC channel, the scheduling of business connections can be achieved using the high-low-level intersection of SDH. However, for EVPL or EVPLn services, service connections are built on the MPLS label. Therefore, if only the high and low-level cross-scheduling of SDH is used, the network usage efficiency is not high.
The Opcity device of the WAN network introduces a large MPLS Switching Matrix, which greatly improves the Statistical Multiplexing capability and network efficiency of the MSTP network for Ethernet data services. The functional architecture of the device is as follows:
In the Opcity technical architecture, the MPLS switching and RPR modules are built into the cross board and support active/standby backup of the Board. This is totally different from other manufacturers in the industry that place the RPR/MPLS connection Scheduling on the branch slot. From the perspective of module functions, the RPR networking and MPLS scheduling modules are network networking functions, NNI-side functions, rather than UNI-side functions. With the built-in MPLS switching and RPR networking modules on the crosstab, The Opcity device supports flexible scheduling and networking of data services, greatly improving the efficiency and networking capabilities of the MSTP network.