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IDD Topology Reconfiguation Plan

Mitch Baltuch
May 23, 1995

Overview

The original topology for the IDD was put together before Unidata had much practical experience with large volume dataflows over the internet. Also, the very nature of the internet was changing due to the switch from a federally funded and run network, to a commercially run network. This change coincided with the implementation of the IDD. As a result of both increased experience and knowledge on the part of Unidata, and the changes brought about by the reorganization of the internet, It has now become necessary to reconfigure the IDD topology.

This will not be a one-time only reconfiguration. The internet is dynamic, rather than static, and this will always necessitate that we monitor the overall network state and modify the topology as needed. However, we can implement a new topology that is well thought out and valid for current conditions, such as they are. Once the new scheme is in place, future modifications should be less sweeping and easier to implement.

Implementaton Steps

The following steps need to be taken to take to accomplish the topology reconfiguration. Each of these steps will be done on a tier-by-tier basis. In other words, the topology will be implemented for tier, starting from the top. Interim lower tier changes will be done only to accomodate the upper level changes.

For Each Tier

Design preliminary target topology

This entails designing a topology based on some initial assumptions that may, or may not be valid. Testing in the next phase will confirm the assumptions, or force changes. In addition, negotiations with possible new relay sites will be done.

Run connectivity tests at all sites

Using monitoring scripts already in place at IDD sites, we will ask all of the sites to check connectivity with selected downstream sites to test the assumptions made in the preceding step. This will be an iterative process depending on what the results from the test show.

Design final topology configuration

Using the results of the testing, we will design a topology that gives up the most efficiency in data transfer.

Implement topology configuration

Implementation will be coordinated beforehand with all sites involved. During the implementation, each site will also be assigned formal failover sites and a list of all sites, their primary and failover feeds and the site administrator information will be listed and made available on the Unidata Web server.

Milestones

Mitch Baltuch <mitch@unidata.ucar.edu>
Last modified: Tue May 23 10:08:33 1995
 
 
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