Abstract

3Com Corp. commissioned The Tolly Group to evaluate its SuperStack 3 Switch 4400, a 24-port Fast Ethernet desktop switch with advanced multi-layer packet identification and classification functionality, for Fast Ethernet throughput, as well as to validate the device's capability to allocate bandwidth in situations where ports experience severe congestion. 3Com also requested that The Tolly Group verify the step-by-step setup for Quality-of-Service capabilities using 3Com's Network Supervisor (3NS) software.

The 3Com SuperStack 3 Switch 4400 is presented as a Fast Ethernet desktop switch designed to combine wire-speed Layer 2 forwarding with practical Layer 4 Quality-of-Service controls for delay-sensitive and mission-critical applications. In Tolly’s evaluation, the 24-port switch was tested for bidirectional Fast Ethernet throughput, congestion handling, and ease of QoS configuration using 3Com Network Supervisor software.  

In Layer 2 performance testing, the switch delivered zero-loss throughput at 95% of wire speed with 64-byte frames, equal to 6,235,534 packets per second in a full-mesh configuration. With larger 512-byte and 1,518-byte frames, the SuperStack 3 Switch 4400 reached 100% wire speed with zero loss, totaling 1,033,834 pps and 357,607 pps respectively. These results indicate that the switch met enterprise expectations for non-blocking Fast Ethernet forwarding under steady-state full-duplex load.  

Tolly also tested the switch in an oversubscription scenario where four Fast Ethernet ingress ports fed two Fast Ethernet egress ports, creating 200% offered load. With QoS disabled, traffic types including SNMP, NBX voice-over-IP, POP3, and HTTP all experienced proportional loss as congestion increased. With QoS enabled, the switch classified and prioritized traffic by policy, preserving bandwidth for high-priority streams such as SNMP and voice while throttling or discarding lower-priority traffic such as Web and E-mail. The report describes this as effectively starving low-priority traffic so that critical services continued to flow during severe congestion.  

A further point of emphasis is manageability. Tolly verified that a QoS prioritization scheme could be configured in only six steps using 3Com’s 3NS software, underscoring that traffic prioritization did not require a complex setup. The test environment used a SuperStack 3 Switch 4400 running version B.01, connected to a Spirent SmartBits SMB-2000 with 24 Fast Ethernet links and two Gigabit uplinks. Overall, the report positions the switch as a strong fit for networks that need both dependable Fast Ethernet throughput and policy-based prioritization for voice and other time-sensitive applications.