A hosted VoIP solution can benefit businesses looking for lower costs, scalability, mobility and simplified administration. For channel partners who sell hosted VoIP, making the right recommendation can increase recurring revenues and expand their customer bases. So, understanding how to ensure a successful VoIP deployment is a key part of the pre-sale process.
Quality of service (QoS) is mission-critical in the implementation of hosted VoIP because it defines how much or how little control the service provider has over the hosted platform, which in turn has a direct impact on the quality of the VoIP solution.
What is QoS? QoS is a set of techniques which helps manage network parameters – specifically delay, delay variation, packet loss and bandwidth. The integrity of real-time applications such as voice and video are especially sensitive to latency (delay), delay variation (jitter) and packet loss. This means the voice conversation or the video session can be compromised if jitter and delay are not properly managed. And, data performance, while less sensitive to delay and delay variation, can be degraded if packet loss is not minimized. QoS can help manage these resources, creating a more predictable hosted VoIP platform.
Key Considerations for QoS. In order to manage QoS, it is important to assess several key factors: traffic classification, scheduling, bandwidth and the customer LAN.
- Traffic Classification. Traffic is generally classified as “best-effort,” “important” and “critical.” These terms apply to the sensitivity to network quality, not the importance of the traffic. Voice is always designated as critical because it is real-time communication. Video frequently also is marked as critical because video images are extremely sensitive to delay. Data can have several different classifications, ranging from important to best effort. CRM traffic would be important while Internet browsing would be best effort, for example.
- Scheduling. Scheduling is the process of matching the “class” of traffic to the appropriate type of network transmission to ensure it is handled appropriately. It’s helpful to think of scheduling in terms of mail delivery from the U.S. Postal Service: all mail is delivered, but some is marked “express” and some is standard. Voice traffic, which is more sensitive to network quality, would be considered “express mail” and, thus, receive preferential scheduling treatment on a QoS-enabled network.