Healthy VoIP Nets�Part XVI�Network Management Architectures: Ixia

Ixia, headquartered in Calabasas, California, is a provider of performance test systems for IP-based infrastructure and services, with support for a wide range of industry-standard interfaces, including Ethernet, SONET, and ATM.

The company also has a wide range of customers—including enterprises, carriers, service providers, network and telephony system vendors, semiconductor manufacturers, and governments—that use Ixia’s test systems to validate the functionality, performance and reliability of complex IP networks, devices, and applications.

Ixia is a public company (NASDAQ: XXIA), with about 800 employees operating in over 30 countries worldwide, generating 2006 gross revenues of $180 million.

Ixia solutions address a broad range of converged networking applications, including service provider triple play (VoIP, broadcast television, and high speed Internet access); IPTV (broadcast television and video on demand); router and switch at the network core, including the emulation of millions of endpoints; carrier Ethernet; application performance; and voice, covering the technology spectrum from PSTN to VoIP to the IP Multimedia Subsystem (IMS). Ixia’s scalable solutions generate, capture, characterize, and emulate network and application traffic, establishing definitive performance and conformance metrics of network devices or systems under test. Ixia’s triple play test systems address the growing need to test voice, video, and data services and network capability under real-world conditions.

Ixia provides several voice testing solutions.

The first, IxLoad, is used to test the scalability and performance of VoIP infrastructure devices such as proxy servers, registration servers, and session border controllers. This system tests the performance of triple play devices and delivery networks by intermixing data traffic with delay and jitter-sensitive voice and video traffic on the same network. IxLoad emulates thousands of VoIP endpoints and measures the quality of the voice service at the subscriber end of the connection. The product supports both UDP and TCP transport, includes user-defined authentication and registration parameters, reports Mean Opinion Score (MOS) values on a per-call basis, and has the ability to adjust the size of jitter buffers in real time. For SIP, IxLoad supports User Agent (UA) emulation with both signaling and media transport, and with MGCP, the product emulates both endpoints and gateways.

A second product, IxVoice, is a comprehensive hardware and software test framework that provides unified VoIP and PSTN test solutions for use by equipment manufacturers, carriers and large enterprises. This system includes a number of test libraries that cover all of the key VoIP protocols, including SIP, Cisco’s SCCP (“Skinny”), H.323, MGCP, and H.248 (MEGACO). Various testing scenarios can be constructed using predefined visual blocks, which automate the testing of both devices and networks to measure the quality of voice and fax calls.

As an example, the SIP Test Library provides the functionality to test SIP-capable devices and systems by simulating SIP endpoints and User Agent actions. The library includes functions that generate SIP messages and simulate a number of call flows—and allow various media sources to be added to the call, including tones, voice, fax, and video streams, thus simulating both valid and invalid network behavior. The system’s measurement capabilities includes the number of originated, connected, received, answered, accepted, rejected, dropped, and disconnected calls; average call setup duration, maximum number of active calls, call failure rate per hour, and other key metrics.

Ixia’s recently announced RAVE (Remote Access Verification Engine) is a custom-engineered hardware and software solution that integrates with carriers’ Operational Support Systems (OSS). This system is a combined monitoring and diagnostic package, enabling Level 1 and 2 support personnel to monitor and analyze systems at a very high level, accomplishing performance and QoS monitoring using both embedded agents and probes.

The associated probe, the XR100, is a small, self-contained appliance that is colocated with carrier’s DSLAMs or other aggregating device. Using the XR100 and the carrier’s OSS systems, simulated VoIP traffic—at network stress levels—is sent over multiple network segments. Performance, QoS, and outages are measured and problems are diagnosed to the component level. RAVE Provides end-to-end service assurance for business services, allowing customers’ SLAs to be monitored minute to minute and month to month. It integrates with the carrier’s network management system, and operates with all triple play components: VoIP, video and data.

Other Ixia solutions for VoIP network management include the IxChariot, a test tool for simulating real-world applications to predict device and system performance under realistic load conditions; IxAutomate, a tool to automate the performance, scalability and functional testing of network devices; and IxANVL, an automated network validation library, which is used by developers and manufacturers to validate protocol compliance and interoperability.

Further details on the Ixia architecture and products can be found at Our next tutorial will continue our examination of vendors’ network management architectures.

Copyright Acknowledgement: © 2008 DigiNet Corporation ®, All Rights Reserved

Author’s Biography
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.

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