"It's the network." This is probably one of the most uttered phrases in companies today. Mysterious slowdowns, dropped connections and other anomalies have network administrators frustrated. To the end user, services either work or they don't work – there's no middle ground. They don't understand that something is working, but temporarily slow. If they can't get an email, or reach a Web site, or whatever their task is for the moment, then it's the network's fault. The administrator is then tasked with determining what the problems is, why it exists and finding a solution. With a full seven layers to troubleshoot, the problem can be taxing.
In an effort to assist network managers in identifying errors and bottlenecks, many vendors have created and released tools to assist network managers in identifying problems (such as HP's Openview, Microsoft's SMS, Novell's LANalyzer and ManageWise, Network General's Sniffer). But it becomes a major undertaking to understand what they are viewing.
The intention of this series is to assist network engineers and operations staff in understanding bottlenecks and traffic issues and their potential causes and cures. With that said, this is not intended to specifically diagnose any one situation. In fact, many of the causes can be compounded or reactive to another factor. It is also important to bear in mind that different switches and routers will have different buffering mechanisms and varied means of queuing packets, some of which may, in fact, compensate for other shortcomings. It is important to discuss these issues with your electronics manufacturer.
Part 1: What's in a packet?
Part 2: Transmission of the frames
Part 3: Other bandwidth issues
Part 4: Bottlenecks
Part 5: Conclusion
Carrie Higbie has been involved in the computing and networking industries for 25+ years. As the Global Network Applications Market at The Siemon Company, Carrie supports the end-user and electronics communities. She participates with the IEEE, TIA and various consortiums for standards acceptance. She has extensive background in all aspects of networking and application development as a consultant, project manager, and Fortune 500 executive and has taught at a collegiate level. She speaks at industry events and has published several articles and whitepapers globally. Carrie holds an MBA and MSBA. Carrie is an expert in TechTarget's Searchnetworking.com, SearchEnterpriseVoice.com and SearchDataCenter.com forums and is on the board of advisors. She writes a weekly column on a variety of topics. She is the President of the BladeSystems Alliance. Carrie has won the "Communication News" Editor's Choice Award for the last two years.