Network bandwidth capacity planning is all about balancing user performance expectations against capital budgets.

Organizations try to control costs by investing in the minimum amount of bandwidth necessary to handle user needs. However, in many cases this could lead to congestion or poor application performance. Moreover, when bandwidth capacity peaks several times in a single day, network performance issues occur, user productivity is reduced, and overall negative effects to day-to-day business are felt.

Challenges to Network Bandwidth Capacity Planning

  • Obtaining accurate information on bandwidth consumption in the network
  • Increasing WAN bandwidth utilization affecting application and user performance
  • Understanding how voice and video application bandwidth is being shared with normal business applications
  • Inability to measure service levels and obtain information on bandwidth consumption needs per application
  • High bandwidth costs falling heavy on budgets

Categorizing Network Traffic

  • Legitimate traffic: Typical business or work related traffic is termed as legitimate traffic. Companies build networks and invest in bandwidth to accommodate business related traffic. If existing bandwidth is currently exceeding capacity and all traffic is genuine, then an upgrade may be necessary. Then again, genuine traffic like backups, file transfers, and VoD replication can be scheduled outside of working hours. By scheduling such traffic to occur outside of working hours, you'll be able to better manager bandwidth consumption and postpone the need for an immediate bandwidth upgrade.


  • Illegitimate traffic: This includes traffic that is generated due to employee activities like video streaming, social networking, downloads, and so on. Most organizations don’t impose restrictions on access to these applications but when bandwidth consumption for such activities affect bandwidth availability, something should to be done.


  • Unwise traffic: This traffic consumes bandwidth from applications like backup tasks and data sync operations performed during working hours. Traffic that is legitimate but instead scheduled to run during working hours is ‘unwise’ traffic. Safely moving or scheduling this traffic to operate outside of working hours will help ensure that it does not consume significant bandwidth during peak work time.

The network engineer in charge of planning for network capacity determines what traffic falls into what category. Information on volume and content of traffic helps size the network accurately to forecast and budget bandwidth capacity needs.

NetFlow Can Help:

Cisco NetFlow helps extract granular information on traffic in the network. This detailed traffic information is useful to characterize and analyze traffic. With Cisco NetFlow you can:

  • Establish a structured and proactive approach to bandwidth capacity planning
  • Better manage deployments in the network, e.g.: MPLS
  • Increase employee satisfaction
  • Save money on bandwidth costs


Are you taking advantage of Cisco® NetFlow for network capacity planning? If Yes, do share with us your comments below.