Digital Convergence, and the creation of a Unified Communications (“UC”) platform have been embraced by many organisations. A UC is the movement of all digital communications traffic, data, VoIP for business and video, over a single physical network through a variety of software platforms.
Obviously, maintaining optimum response times for all classes of traffic is necessary, especially for VoIP for business and video. It is a vital balancing act that IT performs, usually through the creation and management of Quality of Service protocols.
Quality of Service – What is It?
Quality of Service, usually abbreviated as QoS can be defined as the measurement of the overall performance of a network-based service. It is usually measured from the end-user viewpoint as their perception of the service level they see.
Quality of Service – What is Measured?
The fundamental unit of measure is the opinion of users. If they have VoIP calls that continually break up, have gaps and generally don’t allow them to complete a satisfactory conversation, then something is wrong.
Poor VoIP performance can happen for three main reasons, packet loss, latency and jitter. They increase greatly during periods of network congestion.
Packet Loss
Packet loss is exactly as the name suggests. In VoIP, normal speech is digitised and put in normal network packets for transmission over the network connection between the speakers. If packets are lost, the receiver won’t get the complete message as intended.
Latency
Latency is the amount of time a packet takes to get from the sender to the receiver. Obviously, low latency and an equal latency for all packets is essential for a good QoS. Because the route a packet can take may vary between packets, this can be difficult to do, and many QoS devices such as switches buffer VoIP packets to maintain the order of the packets
Jitter
VoIP packets need to be sent in a steady continuous stream between sender and receiver to have an acceptable voice quality. If the network is heavily congested at any point, the steady stream can be interrupted or the gap between packets can vary. Both affect the quality of a conversation. That is Jitter.
These are the three basic measurements when assessing poor QoS performance.
What Causes Poor QoS?
Quite simply, network congestion at any point in the route between sender and receiver will cause packet loss, poor latency and jitter. It can happen in an internal network or at the network interface with the outside world.
Normally, in a VoIP business implementation passing over an internal network and the Internet, a service supplier provides the infrastructure to process and carry the VoIP traffic, and there is sometimes network congestion at the service supplier. Finally, Internet congestion can be a cause.
Bottom line, once internal problems have been resolved, and a poor QoS is still there, it is with your service supplier that QoS issues need to be addressed.
The big question is then, how do service providers deal with VoIP QoS and do they differ in their approaches?
VoIP Service Suppliers and QoS
The first thing to understand is that VoIP service suppliers are not equal. They offer different levels of services at different costs and have different approaches to dealing with customer QoS issues. The short answer to the question “Is QoS the Same in Every VoIP Provider”, is no.
The best way to assess a QoS supplier is the same way as you would with any other service supplier.
Step 1 – Document your requirements, usually in a matrix setting out the mandatory, desirable and nice-to-have elements.
Step 2 – Ask around. Check with other users, carry out Internet searches on websites like HelloPeter for recommendations or otherwise, and gather as much background information as you can, particularly on their attitude to resolving performance and QoS issues.
Step 3 – issue the matrix to selected suppliers for quotations.
Step 4 – Review the responses and identify a preferred supplier and a backup supplier.
Step 5 – Create a Service Level Agreement with the preferred supplier setting out the rules of engagement. A major part will be the identification of the key QoS measurement metrics and how any issues are to be resolved.
A good practice that should be written into the agreement with the service supplier is regular management meetings to review recent performance, identify any current or potential issues and set out steps for resolution. There will be software and hardware updates to the VoIP infrastructure from time to time and these need to be scheduled.
One last point is that not all devices are VoIP capable, and still need a connection to the prior Telco network. If not properly configured, they may cause VoIP problems.
VoIP for Business is the entry point to your organisation and is a key part of your corporate business strategy. It needs to give customers the sense of dealing with a quality organisation. Poor performance is not acceptable in that environment.
