Monday, May 8, 2006

Zarlink Expands Ethernet Switch Chip with QoS Features for IP-DSLAMs, PON

Zarlink Semiconductor expanded its ClassSwitch Ethernet switch family with two new devices designed for network access equipment that aggregates, inspects and modifies real-time traffic in triple play and carrier-grade Ethernet VLAN applications. Targeted platforms include IP-DSLAMs, MTU/MDU (multi-tenant/multi-dwelling unit) switch systems, PON units, and micro-MSPPs (multi-service provisioning platforms) carrying Ethernet services over SONET/SDH networks.

Zarlink's new ZL33032 and ZL33050 chips are Ethernet switches integrating embedded memory with protection switching and enhanced per-flow QoS features -- key elements in the delivery of advanced services including IPTV and end-to-end private VLAN. The ZL33032 embedded memory switch is a fully featured device with 24 FE (Fast Ethernet) + 4 GE (Gigabit Ethernet) ports. The ZL33050 delivers the same features and port configurations, with the option to add external memory to support applications requiring additional traffic burstiness, more complex congestion control and advanced traffic shaping.

The devices also offer rapid failure detection and protection switching features to identify network errors and minimize frame loss. Zarlink said that unlike common "link" based failure detection mechanisms, the ClassSwitch devices feature integrated "protocol" based protection, enabling the user to detect failures at the far-end of the network. The devices incorporate an algorithm capable of periodically sending programmable packet beacons (for example, ping packets) across the network using specialized built-in hardware, without requiring CPU intervention. If a failure occurs in the far-end system all packets belonging to the session can be rapidly diverted to a backup path.

Programmable rate control can be applied to every 10/100 port independently for incoming and outgoing traffic to ensure customers receive only their subscribed bandwidth. The average traffic rate is reduced to below full wire-speed, and port rate can be flexibly configured in 64 Kbps increments. On the input side, flow control will be applied on the traffic's source port until the arriving traffic conforms to the configured rate. On the output side, data will continue to be buffered inside the ClassSwitch device until it can be transmitted to the destination at the requested rate.

Integrated flow-based QoS features allow service providers to maintain secure connections for their customers and control access by detecting unique traffic streams and limiting data rates for specific applications. Packets entering the device are classified to a flow based on user-defined rules, using information such as frame source and destination addresses or applications using the Layer 2 to Layer 7 fields of incoming packets. Up to 1,024 distinct flows can be created per device. The architecture supports per-flow two rate, three-color metering and policing. Scheduling algorithms, such as SP (strict priority) and WFQ (weighted fair queuing), manage packets and prioritize traffic.

Flow metering also enhances network security by detecting and discarding illegal or harmful traffic. To further protect against viruses and malicious attacks, ClassSwitch devices integrate a hardware-based DoS (denial of service) attack-flow engine.

Both new devices are available now, priced at US$74.00 and US$80.91 respectively at 10 K volumes. Other port configuration such as 16 FE+4 GE and 8 FE+4 GE will be available soon.