Abstract

Quintum Technologies commissioned The Tolly Group to evaluate the switching and routing capabilities of its Tenor VoIP MultiPath Switch. The Tenor is a VoIP gateway with integrated gatekeeper that provides both call routing and call switching capabilities. Tests investigated bandwidth optimization, auto-switching, call routing, Cisco 2600 interoperability and voice quality.

Summary of Test Report:

Quintum Technologies commissioned The Tolly Group to evaluate the Tenor VoIP MultiPath Switch, a VoIP gateway with integrated gatekeeper functions designed for seamless integration into converged voice and data networks. The Tenor is engineered to provide intelligent call routing between PBX, PSTN, and IP networks, while ensuring reliability and preserving voice quality. The evaluation focused on Quintum’s proprietary PacketSaver™ for bandwidth optimization, SelectNet™ for automatic failover to PSTN, and the device’s interoperability with Cisco VoIP infrastructure.

Testing demonstrated that PacketSaver™ reduced bandwidth usage by up to 57% by multiplexing multiple calls into a single IP packet stream. The SelectNet™ feature ensured real-time failover to the PSTN when network conditions degraded below acceptable voice quality thresholds, maintaining call continuity transparently. The Tenor’s MultiPath architecture effectively routed calls between IP and circuit-switched networks in a variety of hop-on/hop-off scenarios, while maintaining interoperability with Cisco 2600 series VoIP Gateways and Gatekeepers across multiple H.323 registration and call routing configurations.

Voice quality assessments using MOS and PESQ scoring revealed that the Tenor maintained toll-quality voice (PESQ 4.15 / MOS 4.54) with G.711, and delivered near toll-quality results even under compression with G.723 and G.729 codecs. The combination of intelligent call routing, bandwidth savings, seamless PSTN failover, and proven interoperability underscores the Tenor VoIP MultiPath Switch as a robust solution for enterprises migrating to converged IP telephony infrastructures while needing to ensure service reliability and voice quality.

Key Performance Metrics – Quintum Tenor VoIP MultiPath Switch

• Bandwidth Optimization (PacketSaver™):

  • Achieved up to 57% reduction in bandwidth utilization by multiplexing multiple voice calls into single IP packet streams.

  • Optimized network efficiency without compromising call setup or quality.

• Auto-Switching to PSTN (SelectNet™):

  • Seamlessly switched active calls from IP network to PSTN when network conditions degraded below preset thresholds.

  • Failover was transparent to end users, maintaining call continuity.

• Call Routing (MultiPath Architecture):

  • Supported intelligent call routing between PBX, PSTN, and IP networks.

  • Enabled “Hop On” and “Hop Off” call routing between IP and circuit-switched networks.

• Interoperability with Cisco:

  • Demonstrated full H.323 interoperability with Cisco 2600 Gateways and Gatekeepers.

  • Successfully handled VoIP calls and T.38 fax transmissions in mixed Quintum-Cisco network scenarios.

• Voice Quality (MOS and PESQ Scores):

  • G.711 codec: PESQ 4.15, MOS 4.54 (toll-quality).

  • G.723 codec: PESQ 3.35, MOS 3.82 (near toll-quality).

  • G.729a codec: PESQ 3.47, MOS 3.87 (near toll-quality).