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VOIP QOS - In good voice
VoIP might well be a boon to users, but it can also be a network manager's headache.
Martin Anwyll offers some pain-killing suggestions
It's been a long time coming but VoIP deployments are now a common feature across the business spectrum. It's become the network manager's responsibility to ensure performance and availability, monitor security threats, and ensure call quality.
Handling the voice service has not always been the network manager's concern. In larger enterprises, particularly, voice telephony was a separate though allied discipline. With VoIP, however, the divide between voice and data has become blurred and now all network managers are expected to deal with voice - quality, traffic and availability - plus the underlying hardware and application issues.
It's no easy task replicating the quality and reliability of a circuit switched network. As the number of users and services can only increase over time, network managers are looking at a serious challenge on every level.
How do network managers ensure they are providing the level of service required by users?
Its voice - but not as we've known it so far. Of all the technology-driven services in the workplace, voice is the one that users have come to take totally for granted. Every now and then there may be occasions when call quality may be impaired but extended downtime - or any downtime at all - is a rare occurrence.
However much money the business stands to save using VoIP, it counts for nothing if productivity is lost or the relationship with customers or suppliers is undermined. Suffice to say anything less than 99.999 per cent reliability is unacceptable.
The reality is that VoIP is a complex application. It runs on a generally complex network delivering a set of equally complex services. It is a packet-switched application, which means it is impaired by traffic congestion, traffic spikes, and all those other network events that the voice service has so far avoided.
There are a huge number of variables that can impact on VoIP service performance outside the application itself - including servers, the supporting network, system components, middleware, operating systems as well as other associated applications.
How do network managers identify problems automatically, avoiding any situation in which they're seen to be reacting to user complaints, or obvious degradations in service such as echo, delays or distortion? The answer is deceptively simple: they ask their supplier for a comprehensive VoIP management solution that covers every aspect of the VoIP infrastructure across the entire lifecycle. The solution should view and manage the VoIP network as a business service, and demonstrate a practical understanding of its interactions with other services and applications.
A solution that allows access to information on all relevant network components and applications from a single console is more efficient and makes life a lot easier.
At a very basic level, a VoIP network management solution should combine voice-specific monitoring tools that detect jitter, packet loss, delay and call quality, with network management facilities that give an insight into the devices, port configurations and network availability.
The very fluid nature of VoIP - in which conditions can change second by second - dictates that management functions should be operational constantly and in real time. An effective VoIP management solution will drill deep into the network to pinpoint the root of a problem. The best tools will monitor jitter, packet loss, throughput, volume issues, delay, and other quality issues both from within the network and external applications such as voicemail and call centres.
The ability to monitor the VoIP infrastructure in real time is, arguably, the defining factor in delivering a reliable, high audio quality VoIP service. Continuous monitoring is not only important in identifying and automatically resolving potential problems; it's the vital first stage in the planning and optimisation of this critical process.
A VoIP management solution should provide a range of monitoring facilities - coupled with automated corrective actions - including call quality, call success rates and fault and performance management.
Any thoughts of adapting existing management tools should be dismissed right away. Standard network management tools don't fit the bill as they only pinpoint faults at precise points across the network path where the links between devices were failing to complete. This approach won't work for VoIP as it is a dynamic, packet-switched application in which no two paths will ever be the same.
There is already a huge contingent of products and ‘solutions' on the market. However, there is a growing consensus that customers should opt for a comprehensive, integrated solution that encompasses the entire VoIP environment and lifecycle. A truly effective solution should seamlessly integrate the best available technologies.
Security is the one area in which most VoIP management solution providers have yet to offer a credible response. Traditional firewalls don't protect VoIP calls as voice packets must be encrypted and traverse a firewall without undue latency. Any network that ends with an IP address is vulnerable to unauthorised calls, spammers, information theft and other malicious activity by hackers and DoS (Denial of Service) attacks that can, at best, adversely impact call quality. In a worst-case scenario, the entire network can be at risk during a VoIP security breach.
Security, therefore, should be a priority in the buying equation. To be effective from a security perspective, the VoIP network management system must provide an automated security layer that monitors the entire VoIP environment in real time to increase protection levels and ensure layered defences. It should be capable of correlating security events and alert on security breaches and performing analysis and forensics - all in real time.
Our definition of a solution goes beyond excellent products seamlessly integrated into a scalable, flexible whole. The framework on which that solution is based is fundamental in enabling users to control rather than simply manage their VoIP services and environment. Once the framework is in place, network managers can add the flexible tools, management modules and customisable scripts they need - as and when they are needed - to ensure a high quality user experience (QoE).
We're all used to talking about Quality of Service (QoS), which is a term that relates to network optimisation. QoS is about ensuring network elements apply consistent treatment to traffic flows as they traverse the network.
Quality of Experience (QoE) is the crucial end result of QoS. QoE refers to the user's perception of quality, which, as we all know, is ultimately the measure by which the success of a VoIP service will be defined.
Martin Anwyll is Product Line Specialist, VoIP Solutions (EMEA), Attachmate
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