Data Services Newsletter

Volume 5 : No 2 : April 2003

AppareNet network analysis tool being evaluated by the IRIS DMC

AppareNet Logo

The IRIS-DMC has acquired for evaluation, a network analysis product from jaalaM Technologies AppNeta called AppareNet. The product is described as “a network intelligence system that measures the performance of network infrastructure”.

Here at the DMC we occasionally hear about network performance issues from users who are uploading or downloading data to our ftp servers, or browsing our Website. Determining what or where these problems are has been challenging, if not impossible.

The AppareNet software appears to be just the kind of tool needed to make these kinds of determinations. AppareNet uses network-sampling techniques to send precisely timed test packets along the same network path that an application uses. The packets are small enough to traverse the network without causing impact on the existing network traffic. As these packets travel through the network, they are affected by delays, restrictions and limitations. As the packets return, AppareNet uses proprietary analysis and mathematical modeling to report performance measurements that intelligently describe the network. The following performance points are reported for each hop:

  • MTU (Maximum Transmission Unit)
  • Bandwidth (maximum achievable bandwidth on a link)
  • Propagation Delay (delay caused by the length and type of medium used)
  • Utilization (percentage of bandwidth being used)
  • Jitter (stability or variation in packet delay)

AppareNet also analyses the returned test packets and looks for patterns of behavior using proprietary analysis techniques. These patterns often result in telltale problem “signatures”. Together with the performance measurements the signatures provide the ability to find network configuration problems that are typically quite difficult and time-consuming to diagnose. The following faults are possible to be uncovered:

  • Bottlenecks & congestion points
  • Full/half duplex mismatches
  • NIC performance problems
  • MTU discrepancies
  • Rate-limiting queues
  • Media errors
  • Overlong half-duplex links
  • Out of sequence packets
  • Black-Hole / Gray-Hole hops

IRIS has high hopes that the AppareNet product will help us provide the best possible network to users, and to help uncover where problems may exist between the DMC and user machines.

by Rick Braman (IRIS Data Management Center)

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