Quintum Technologies, Inc., a privately held company headquartered in Eatontown, New Jersey, has been developing VoIP solutions for both the enterprise and service provider markets since 1998. Their innovations constitute the Tenor line of products.
For the enterprise, these products address VoIP switching and gateway needs, including support for next generation IP-PBXs, unified communications, and the integration of legacy voice equipment with VoIP communication systems.
On the carrier side, Quintum solutions have been used to support services that include SIP trunking, hosted IP-PBX, IP Centrex, and hosted call centers. The Tenor systems are distributed in 67 countries around the world.
Quintum has developed several technologies, incorporated into various elements of their architecture, that optimize VoIP packet processing.
- The MultiPath Architecture allows calls to be selectively sent to the IP network based upon network management configuration settings.
- The MultiPath Call Routing process intelligently routes calls between premises switching systems, the PSTN, and the IP network, thus achieving the optimum combination of call cost and quality.
- The NATAccess firewall technology allows VoIP implementers to keep their gateways behind Network Address Translation (NAT) devices and NAT-enabled firewalls. This process performs the network address translation within packet payloads during the call setup process, thus providing the outside party’s router with the appropriate public IP addresses for internal users.
- Finally, the PacketSaver technology multiplexes voice calls traversing the network to reduce the overhead created by IP packet headers.
Quintum’s session border controller is called the Tenor Call Relay; it provides a VoIP conduit between multiple IP networks. The system is available in two different platforms: the Call Relay 60, which supports up to 60 simultaneous voice calls and 3,600 calls per hour; and the Call Relay SP (service provider), which supports up to 672 simultaneous voice calls and 18,000 calls per hour.
Both systems are compliant with H.323 version 3 and the SIP standards, and can provide signaling protocol conversion between the two for inter-networking applications. The hardware is compatible with 10/100 Mbps auto-sensing Ethernet interfaces, and also provides support for IP Type of Service (ToS) and Differentiated Service (DiffServ) quality of service standards.
The configuration and management capabilities are especially strong, with a command line interface, a Simple Network Management Protocol (SNMP) version 2 Agent, and remote Telnet support for network management console access, plus public and private dialing plans and access to call detail records.
The main feature that differentiates Quintum’s Call Relay product from other SBC vendors is its patent-pending PacketSaver technology. This is a packet assembly technique that queues up several voice and/or fax packets and then multiplexes them into one or more larger packets, without introducing unacceptable delays. Packets from one or more sampled voice conversations are combined together into one large (multiplexed) voice packet that is headed for the same destination endpoint on the other side of the network. When that packet is full, or a pre-determined packet assembly time limit has been reached, the multiplexed packet is sent to the destination end point. At that destination, the packet is de-multiplexed, allowing the original voice and/or fax information streams to be to be distributed to their intended end points.
Using a Call Relay SBC in front of a non-Quintum network or gateway enables the user to take advantage of the greatly reduced bandwidth consumption for multiple calls flowing between the two end points. For example, a Call Relay could be used in front of a Cisco gateway to reduce bandwidth consumption by up to 50 percent on the WAN link between the two endpoints. For inbound calls, the Call Relay terminates the PacketSaver-encoded packets arriving at the Call Relay and converts them to standard packets to forward to the Cisco network. For outbound calls, the Call Relay terminates the standard packets being generated by the Cisco network, and converts them to PacketSaver-encoded packets for transmission over the WAN. This reduces the bandwidth requirements for the long distance WAN link, which is likely to reduce that link’s cost. In addition, the PacketSaver process generates fewer large packets that must be transmitted over the WAN link. Since smaller packets can be handled more efficiently (less packet fragmentation), the routers in the WAN path also operate more efficiently, which reduces network congestion. This feature is particularly beneficial when used with satellite link transmissions.
In summary, the Call Relay family is differentiated from competing products in that they offer smaller, less complex devices that are optimized to meet the needs of enterprise and small service provider customers. Further details on the Quintum Technologies architecture and products can be found at www.quintum.com. Our next tutorial will continue our examination of vendors’ SBC architectures.
Copyright Acknowledgement: © 2007 DigiNet Corporation ®, All Rights Reserved
Mark A. Miller, P.E. is President of DigiNet Corporation®, a Denver-based consulting engineering firm. He is the author of many books on networking technologies, including Voice over IP Technologies, and Internet Technologies Handbook, both published by John Wiley & Sons.