The ZyXEL IES-612-51A/IES-612-51 is a 12-port ADSL2/2+ mini DSLAM. It has 2 Fast Ethernet (100Base-Tx) WAN ports that can be configured as uplinks or cascading ports. In order to support more than 12 subscribers, three network topologies can be constructed for different circumstances: Daisy Chain is the one with the minimum number of uplink connections; Loop structure is the topology where the single point failure issue can be avoided in the uplink connections with RSTP (IEEE 802.1w) protocol; Tree structure is the most robust one where each IES-612-51A/IES-612-51 has its own uplink connections.

The IES-612-51A/IES-612-51 is equipped with ATM-based multi-paired bonding feature. Two physical ports can be bonded together as a group, while all upper-layer traffics of a group can be segmented and transmitted over the member ports. If one of the member ports fails, the conveyed traffic will be moved to the other port. When the failed port recovers, it will seamlessly return to the group and share the transmission of the upper-layer traffics.

 

Within a bonded group, the underlying bit rates of the individual ports can be freely and independently changed by their respective PHY layer. The port-bonding feature not only provides higher bandwidth to subscribers, but also offers more reliable pipes for business applications.

 

The IES-612-51A/IES-612-51 can be powered thorough either AC or DC inputs; and the design of power modules allows replacement to be performed manually in the field. As a result, Telco operators can inventory the necessary PWBA first and order the correct power modules later for different requirements.

 

The IES-612-51A/IES-612-51 comes with complete ATM and Ethernet QoS, as well as various IP QoS features (Packet classification/Rate Limitation/Queue Scheduling). The seamless QoS-mapping not only allows consistent and appropriate traffic treatment of packets, but also enables fulfillment of triple-play services.

 

The number of supported multicast groups is 256, while each group can have 13 members. At least 30 multicast IGMP join/leave requests can be processed in one second and the maximum channel processing time is less than 250 ms. For security, anti MAC address spoofing, broadcast storm prevention, MAC count limiting and packet filtering features are provided. Triple-play services like high-speed Internet access, VoIP, Near VOD, Broadcast TV and TV on Demand can be easily provided as well.