By Mark Langanki, Chief Operating Ofﬁcer at Spanlink Communications
Cisco clients can leverage capacity management tools to determine if the appropriate number of trunks and ports are in use for their environments. This offers clients an opportunity to optimize their network usage and minimizes the risk of purchasing too few or too many of these critical, but expensive resources.
But if you’re in the market for a tool that can help you utilize your capacity more efﬁciently, be wary of products that fall short of ITIL’s best practices. There are a number of Cisco partners that lack the understanding and the capability of providing clients with “true” capacity management tools. As a result, clients are unable to accurately measure needed metrics, such as average handle time, busy hour call attempts and calls per second.
To access these key metrics and properly evaluate each offering, you must ﬁrst understand the full capabilities of a capacity management system. ITIL deﬁnes it in three distinct levels: component, service and business.
This is the most rudimentary level of capacity management, which measures a single device, circuit or element of a structure. Many capacity tools stop here, neglecting to deliver information that can truly enhance service. Complex Cisco environments don’t use just one component, and measuring each item individually fails to explain how they work collectively.
The service level of capacity management goes beyond measurements of individual components and delivers metrics based on multiple resources that deﬁne one service.
Business capacity, or “true capacity”, takes a look at the entire system. It starts with data captured at a component level, but then deﬁnes how the components act together to deliver a service. Once the service can be measured in total, the correct metrics and key performance indicators (KPIs), such as busy hour call attempts, average handle time and calls per second, can be calculated for reporting and monitoring.
This is often where capacity management tools fall short. Traditional capacity management tools, originally developed for TDM or PSTN environments, poll for data once every ﬁve minutes. In a VoIP environment, however, this method doesn't allow for the granularity of data needed to calculate these KPIs. Take voice trunks as an example: in TDM or PSTN environments, we talk about trunk groups, not necessarily circuits or ports, as a trunk is deﬁned to go beyond a single component. In VoIP, the thought of trunks and trunk capacity is lost due to the nature of the technology. Trying to calculate it the same way is impossible.
True capacity management in VoIP environments requires continuous data polling to dynamically construct the view for the data as a component, a service, as well as the KPIs needed from the business level.
When shopping for a capacity management solution for a Cisco environment, ask vendors how their tools map to the ITIL-deﬁned levels of capacity management. After all, there’s a huge difference between measuring the capacity usage of one port, and being able to strategically plan for your system-wide network needs.