By Marc Lippe, Director, Worldwide Field and Corporate Marketing, InfoVista
Everyone would agree that ensuring QoE is key to having (and keeping) happy customers. The problem is that a customer’s “quality expectations” are a bit of a moving target. For example, a residential customer may want a fast Internet connection when downloading a YouTube movie but five seconds give or take won’t make a huge difference. However that same customer will not be happy if it takes even two seconds to change the channel when watching IPTV.
So while we expect an end-user’s quality expectations to be influenced by the level of service they purchased, we can’t forget that it is also dependent upon the particular application they are using. With an ever increasing array of new services, this makes ensuring a high quality customer experience no easy task for service providers.
A major trend in QoS over the last couple years is the movement toward “hierarchical” QoS. Service providers typically design networks using a concept called over-subscription. Like an airline company that always overbooks because it knows some passengers are going to cancel at the last minute or just not show up, service providers know that not everyone is going to be using the Internet at the same moment. Because of this, the network might be designed to handle 1/8 of the capacity that has been sold.
With this level of infrastructure capacity, a further limit is needed beyond the limits put on customers based on their subscription. These additional limits are placed on how many resources can be allocated toward each type of network traffic: data, voice, and video. This is what is meant by hierarchical QoS. Each customer has their own queue with its own limits defined, but then the parent queue has another limit defined, which is an aggregate of everything. So while a packet may fall within the limit of a customer’s own queue, it may nevertheless get dropped by the parent queue because everybody in the neighborhood is watching the same Internet video, or the amount of traffic sent is more than the parent queue can handle for some other reason.
Of course, all of this makes network monitoring much more complex. With hierarchical queues, OSS systems not only have to discover these new queues, they have to discover the relationships between parent and child queues and allow network operators to navigate around, having the visibility to see these relationships. When a customer is not receiving the expected QoE, you have multiple queues to troubleshoot.
With this growing network complexity, having the right OSS system in place is critical to managing the end-user experience.
Today’s performance management systems should be capable of working with hierarchical QoS, being able to track and record—in real time—latency, jitter, and packet loss. Solutions should detect potential problems before they occur to reduce, or entirely eliminate negative impacts on end-users. This proactive approach to service management has become essential to meeting and exceeding customer expectations.
The thing to remember is that customers will be drawn to a truly reliable service, which means less customer churn and faster return on infrastructure investment—and that is good business.
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