Abstract

Tolly Group Report #202129 (May 2002) validates Avaya’s P330 Stackable Switching System, including the P332G-ML 12-port Gigabit switch, P333T-PWR PoE Fast Ethernet switch, and G700 Media Gateway with S8300 Media Server. Tests required zero-loss forwarding while measuring voice quality, QoS prioritization, PoE reliability, and stacking bandwidth.

Voice quality under congestion. Baseline PESQ scores reached 4.13 (male clip) and 4.01 (female clip), exceeding the 3.8 toll-quality threshold. With links oversubscribed at 220% and QoS disabled, PESQ dropped to 1.58. Re-enabling QoS restored PESQ to 4.00, confirming that priority queuing protects VoIP during heavy load.

QoS verification. Engineers oversubscribed a P332G-ML port two to one, tagging one stream with Layer 2 802.1p and another with Layer 3 DSCP. The switch delivered zero packet loss to the DSCP stream while progressively throttling the lower-priority VLAN traffic, proving correct hierarchy between Layer 3 and Layer 2 markings.

Stacking and throughput. Three P330 units connected via Octaplane achieved 15.2 Gbit/s, which is 95% of the 16 Gbit/s theoretical backplane, while each standalone P332G-ML forwarded 100% of line rate for 64-, 512-, and 1,518-byte frames at both Layer 2 and Layer 3.

Power over Ethernet. The P333T-PWR successfully powered Avaya 4612 IP phones, sustaining calls while phones were power-cycled from the switch.

Conclusion: Avaya’s P330 family delivers wire-speed switching, resilient stacking, accurate QoS that preserves toll-quality voice at 220% oversubscription, and dependable PoE, making it a solid choice for converged enterprise networks requiring integrated voice, data, and modular expansion without performance compromise.