Internet telephony, commonly referred to as VoIP, grew in the past few years that it became a real threat to traditional telephony services where toll-bypass was the main concern. Bypassing local and international telephone toll fees was the main concern not only for enterprises but individuals as well became heavy users for national/international VoIP calls.

Internet telephony completely relies on the internet’s data infrastructure with all of its inherent delays, mesh connections, and bottlenecks. Data being delay-tolerable in nature is not greatly affected by unoptimized routes which add significant delays to network response time. Voice, being delay-sensitive, mandates not only the use of short optimized routes to final destination points, but also mandates that all communicating parties (source/destination and intermediate transit points) respect the voice being prioritized over data transmission. The earlier stages of VoIP usage were greatly focused on toll bypass only regardless of call quality. Nowadays, VoIP call quality is a main concern as it grew to be adopted by global communication carriers with a suite of services for enterprises and individual users.

As VoIP usage grew fast, granular control over VoIP parameters like quality, bandwidth, compression, routes, route failure recovery, and link status became essential to allow carriers and service providers commit themselves with service level agreements (SLA) with their customers. VoIP monitoring tools scale to perform the following tasks just to mention and not to count:

1. VoIP call quality of service (QoS) using Mean Opinion Score – MOS

2. when call quality becomes lower than a certain threshold, calls are redirected through a normal PSTN circuit switched call.

3. End-to-end calls QoS between VoIP gateways participating in a call.

4. delay and jitter monitoring

5. per-call compression ratio

6. per-call bandwidth utilization

7. DSP resource utilization

An example of telephone systems manufacturers whom adopted this track is Nortel Networks. With a heritage of 120 years in communications industry, Nortel has pioneered in IPT telephone platforms and VoIP applications. Of the many applications Nortel offers to its customers, comes a management tool on its IPT Succession and BCM systems called Quality of Service Monitor (QMON) that performs the above tasks and many more.