Rolling Review: Alcatel-Lucent OmniSwitch

Alcatel-Lucent has the experience on the carrier side in technologies that TacDoh, the fictional company in our switch infrastructure Rolling Review, will implement, such as a PBX-to-VoIP migration and, in the future, carrier Ethernet.

But while Alcatel-Lucent's proposed design, based on a chassis core and stacked switches at the edge, meets our needs, we're concerned by the lack of redundancy in the network redesign and in the Power-over-Ethernet implementations. These are two critical areas for our fictional company.

Alcatel-Lucent's design uses a chassis-based OmniSwitch 9700 (OS9700) core switch/router combined with OmniSwitch 6850 (OS6850) stackable switches for the departments and data center. The OS6850 switches for all departments except the warehouse are interconnected over 10-Gbps fiber.

Although we didn't require the access switches to be interconnected over 1000Base-TX in the RFP, Alcatel-Lucent's design would require us to run fiber from the wiring closets to the OS9700. We were planning to do this in the future, so deploying this scheme would just accelerate those plans.

Switches are managed using Alcatel-Lucent's OmniVista network manager. OmniVista is a modular application that can be extended to support other Alcatel-Lucent products, such as its VoIP and NAC systems. OmniVista supports bulk configuration of the network for rapid provisioning. The switch is accessible over SSH, HTTP/HTTPS, and FTP for management functions.

Using a chassis at the core and stackable switches at the edge makes sense for a growing company like TacDoh. The OS9700 is a 10-slot chassis populated with two management blades and three power supplies for redundancy. Five slots are occupied with four blades of dual 10-GB interfaces and one slot for a blade containing 20 10/100-Mbps interfaces and two 1-Gbps slot interfaces. The 10/100 interfaces can be gigabit-enabled for an additional fee. The remaining three slots can be used for future expansion.

Departmental OS6850 switches that support PoE are connected to the OS9700 core switch over 10-Gbps links. The first-floor conference room is connected via a 1-Gbps uplink. We could shave off a little under $12,000 by dropping the 10-Gbps uplinks between the access switches and the core. The OS6850s in the data center are redundant, and the OS9700 core switch is interconnected to both. The access switches don't have redundant uplinks to the core, leaving a single point of failure. This concerns us because a resilient network will be vital when TacDoh rolls out VoIP.

Eight OS6850 switches can be stacked using two 10-Gbps interfaces, one going up and one down, for 20 Gbps total. Switches can be inserted or removed from the stack without disrupting connectivity, providing an easy way to add capacity or replace hardware. The uplinks to the core are through a single interface, making that particular switch a single point of failure as well. We would rather increase reliability using redundant links in separate switches.

The design lacks power coverage for all ports in the switch. The OS6850's 360-watt power supplies have a PoE power budget of 240 watts available. At 15.4 watts per port, a switch could only power 15 ports. At 8 watts, the OS6850 could power 30 VoIP phones, but without power backup. The optional 510-watt power supply can power as many as 48 ports.

Alcatel-Lucent's OS6850, like other modern switches, comes with quite a few security features, including DHCP and ARP snooping, which detects network traffic; IP lockdown to restrict which hosts connect to the network; and Etherbreaker, Alcatel-Lucent's frame-based anomaly detection.