Enterasys 10G switch goes its own way - fast

Attention network executives with maxed-out backbones: Enterasys Networks has a switch for you. The Matrix E1 that will be announced next week offers a 10 Gigabit/sec interface that blazed through our laboratory tests with line-rate throughput and impressively low latency.

Enterasys is marketing the $25,000 Layer 2 switch as an aggregation device that moves traffic between a single 10G bit/sec interface and 12 Gigabit Ethernet interfaces, a useful configuration for data centers and server farms.

On the downside, the 10G-bit/sec interface on the Matrix E1 is not 10G Ethernet, but a proprietary variation. The 10G-bit/sec offering uses optics the IEEE considered but rejected for 802.3ae, the 10G Ethernet standard. As a result, this interface won't talk with 10G bit/sec interfaces from other vendors.

Note that all 10G-bit/sec interfaces are proprietary now and will remain so until the IEEE ratifies the 802.3ae specification, probably between March and June 2002.

Enterasys will ship two standards-ready versions of 10G Ethernet interfaces before the IEEE ratifies 802.3ae, says John Pappas, director of technical marketing. Those include the 10GBase-LR and 10GBase-LX4 interfaces.

Upgrading to the standards-compliant versions will be simple because the modular 10G-bit/sec interface on the Matrix E1 is field-upgradable.

Setting up and managing the Matrix E1 is a snap. The device offers command-line and graphical user interface options for configuration, with the former bearing more than a passing resemblance to Cisco's IOS. While the command-line interface isn't a complete IOS clone, it's close enough so that a newcomer to Enterasys products could navigate it within minutes.

For network management, the Matrix E1 offers an integrated remote monitoring agent, a feature not always present in Layer 2 devices in general. The Matrix also supports the virtual LAN management information base..

Enterasys says it doesn't plan to add Layer 3 IP routing support to the Matrix E1.

Unlike most early adopter products, the Matrix E1 10G-bit/sec interface delivers line-rate throughput regardless of frame length or number of hosts.

To see how well the Enterasys boxes aggregated bandwidth, we set up a test bed with two Matrix E1 switches linked over a 10G-bit/sec backbone. Then we pounded the backbone with line-rate traffic from a Smartbits traffic generator/analyzer from Spirent Communications.

In the worst case, we offered 64-byte frames at line rate representing 5,000 hosts. That's the equivalent of taking an entire midsized corporation's traffic, cranking it up to 100% utilization and then feeding it all into one interface. Average usage levels on corporate production nets are typically in the 10% to 30% range, with only occasional higher spikes. Even in this scenario, the Matrix E1 didn't come close to crumpling.

We ran tests with 64-byte and 1,518-byte frames and emulated one host per interface. We offered traffic to 10 1G Ethernet interfaces on each Matrix E1, with all traffic destined across the 10G-bit/sec backbone to 10 other 1G-bit/sec interfaces on the other switch. Because we offered an aggregate of 10G bit/sec of traffic, the Matrix E1 should have been able to forward all traffic without loss.

And that's exactly what we saw. The Matrix E1 moved traffic at line rate in all cases. Even when we reconfigured the Smartbits analyzer to represent 250 logical hosts per interface, the result again was line-rate throughput.

The results with large numbers of hosts represent a big improvement for Enterasys. Earlier switches such as the Cabletron SSR suffered from a poor hashing algorithm that caused massive frame loss whenever those switches were hit with a large number of entities - be they media-access control addresses, IP addresses or port numbers. Our tests show that the Matrix E1 switches do not have this problem, at least not at Layer 2. Additionally, Enterasys has since rebranded the SSR series to be the XPedition line and has conducted some recent testing of products in this line using its own engineers and states there is no frame loss issue at this point in time.

For some applications, latency is an even more important metric than throughput. With these delay-sensitive applications such as voice-over-IP and streaming media, even small amounts of delay can seriously degrade session quality.

Our measurements suggest the Matrix E1 won't add much delay for any type of traffic. Per-frame latency was remarkably low regardless of the number of logical hosts we used.

The two Matrix switches introduced an average of about 6.5 microsec of delay with 64-byte frames and an average of about 47 microsec with 1,518-byte frames. Because we used two switches in our test bed, these measurements should be divided by two to describe single-box delay.

We also noted only negligible variation in average latency between tests with one logical host per interface and tests with 250 logical hosts. Ergo, it's possible to add hosts to the network at will without fear of performance degradation.

For network managers looking to break bandwidth bottlenecks right now, Enterasys has a full 10G-bit/sec pipe shipping next month.

Matrix E1 optical access switch 4.2 Rating Company: Enterasys Networks, (978) 684-1000, www.enterasys.com Price: $25,000 base system ($27,000 as tested). Pros: Excellent throughput and latency; simple command-line and graphical interfaces; RMON support included. Cons: Proprietary 10G-bit/sec interface; relatively expensive; no Layer 3 support.

Matrix E1 optical access switch Performance 50% 5   Features 20% 2   Management 20% 5   Price 10% 3   TOTAL SCORE 4.2

Individual category scores are based on a scale of 1 to 5. Percentages are the weight given each category in determining the total score. Scoring Key: 5: Exceptional showing in this category. Defines the standard of excellence; 4: Very good showing. Although there may be room for improvement, this product was much better than the average; 3: Average showing in this category. Product was neither especially good nor exceptionally bad; 2: Below average. Lacked some features or lower performance than other products or than expected; 1: Consistently subpar, or lacking features being reviewed.

Newman is president of Network Test, an independent benchmarking and network design consultancy in Westlake Village, Calif. He can be reached at dnewman@networktest.com.