To improve bandwidth management, some service providers have tried to use concealed mechanisms to minimize the impact of undesired applications, going as far as interfering with user sessions.
Other service providers tried to introduce transfer caps -- metered and/or tiered service plans that bill customers for the amount of data consumed -- that started with ridiculously low numbers clearly aimed at business problems besides solving traffic management issues. No wonder bloggers and industry press had a field day.
To avoid repeating these mistakes, try some of the following approaches to rational bandwidth use and traffic management are in order.
- Be honest with your users: Educate them about the issues, bandwidth limitations, and what you're doing to manage traffic and ensure that everyone has a good Internet experience. Some service providers are very specific in their definitions, including a real-time traffic graph of bandwidth use for users.
- Give customers realistic choices and usage plans. Some customers only want to surf the Web and read email. Others want to run P2P applications or watch streaming video. The choices aren't good or bad; they're just different. Give users a choice of usage plans and prioritize traffic based on that choice.
- Don't penalize your customers. It's usually better to downgrade the service of customers going over the monthly (or weekly) quota than to charge them automatically. Obviously, you should immediately inform them that they've exceeded the limits and give them an option to buy an additional transfer quota.
- Be as fair as possible. Networks aren't usually busy in the middle of the night. Service providers can give customers a free ride during that time frame. The knowledgeable users of peer-to-peer applications will quickly reconfigure their clients and stay off your network during peak hours.
Numerous mechanisms and technical solutions can be used to achieve these goals. Sometimes you might need dedicated boxes that can perform deep packet inspection (DPI), or it might be enough to monitor per-port utilization and interface counters, then react accordingly.
Don't forget: Whatever you do, keep your customers informed and happy.
About the author: Ivan Pepelnjak, CCIE No. 1354, is a 25-year veteran of the networking industry. He has more than 10 years of experience in designing, installing, troubleshooting and operating large service provider and enterprise WAN and LAN networks and is currently chief technology advisor at NIL Data Communications, focusing on advanced IP-based networks and Web technologies. He is the author of the Cisco IOS Hints and Tricks blog, and his books include MPLS and VPN Architectures and EIGRP Network Design.