S2500 Series supports the carrier-level Ethernet ring protection protocol with less than 50ms recovery time, STP/RSTP/MSTP, backup uplink ports, and LACP link aggregation to cater to the requirements of high reliability of carriers; S2500 Series has powerful ACL functions to access and control L2-L7 data based on physical port, providing carriers flexible and various policy control methods; S2500 Series supports In-Service Software Upgrade (ISSU) to ensure the unremitting data forwarding during system upgrade; S2500 Series supports various L2 multicast functions such as IGMP-snooping, fast-leave and MVR to fully meet the operation requirements of carrier’s IPTV. Easy Management and Maintenance S2500 Series supports many management modes such as the CLI, Telnet, SSH, SSL and SNMP. S2500 Series supports the WEB management mode, which is easy and efficient for installing and debugging the device. S2500 Series supports FTP, TFTP, and SFTP. S2500 Series supports ISSU (In-Service Software Upgrade). S2500 Series supports SNMP and BDCOM NMS smart network management platform. The combination realizes automatic equipment discovery, network topology management, equipment configuration management, performance data statistics and analysis and trouble management. S2500 Series supports Zero Touch Provisioning (ZTP) function to minimize manual operator intervention and helps reduce customers’ initial deployment costs. Enhanced QoS S2500 Series supports priority retagging and complicated flow classification based on VLAN, MAC, source address, destination address, IP or priority, better streamlining carrier’s services. S2500 Series provides flexible bandwidth control policies, supporting port-/flow-based flow limit, ensuring the line speed forwarding of each port. S2500 Series supports multiple queue schedule algorithms such as SP, WRR and “SP + WRR”. Security+ Equipment-level security: The advanced hardware infrastructure design realizes the level based packet schedule and packet protection, prevents DoS-/TCP- related SYN Flood, UDP Flood, Broadcast Storm or large traffic attacks, and supports level-based command line protection, endowing different levels of users with different management permissions. Perfect security authentication mechanisms: IEEE 802.1x, Radius and BDTacacs+. S2500 Series supports storm/multicast/unicast limit, ensuring the normal running of equipment in harsh network conditions. S2500 Series supports perfect ring detection mechanism, ensuring the long-term stable running of network. S2500 Series supports port isolation within the same VLAN, DHCP-Snooping, and IP + MAC + Port binding.