Internet Backbone Index

Art Houle houle at
Sat Jun 28 16:58:41 UTC 1997


  We also have a 'ping' based local monitoring program. We monitor
response from our ISPs, national NAP's and DNS of local interest. See:

And you can get the source at:

It is table configurable to meet your local needs.


On Fri, 27 Jun 1997, David P. Maynard wrote:

> Here is one alternative metric.  I have a monitor program that measures 
> single-packet ping times to name servers that are registered as 
> authorities.  I figure that people should put their name servers in a "good" 
> position on their network and that they should always be up and running.  My 
> goal is to monitor O(1000) hosts at regular intervals (currently 10 minutes), 
> but the list currently hast just over 400 sites.  I started with the web 
> access logs for a very large site with a worldwide user base, looked up the 
> registered servers, then hand-pruned the list to weed out sites 
> that block ICMP, etc.  ICMP echo obviously isn't the best metric in the world, 
> but it has low overhead and allows me to monitor a large number of sites 
> without being disruptive.  (Most people shouldn't mind a single ICMP echo 
> packet every 10 minutes.)
> It's been very interesting to watch the graphs as various backbones have 
> glitches.  For awhile I was comparing connectivity from a single-homed site to 
> a 5-way multi-homed site.  The difference in fault tolerance was dramatic.  
> The next step is to combine some policy routing with some /24 network 
> announcements that are only announced from one backbone to compare 
> connectivity via MCI, Sprint, BBN, and UUNET.  (Ie, run parallel copies of the 
> monitor in an environment that simulates single-homed connectivity from each 
> provider.)  The results should be interesting, but I wouldn't want to claim 
> that they represented anything more than a measure of connection quality from 
> the particular sites where the tests were run.
> At the moment, the tool and the data are proprietary since I wrote it for a 
> particular client, but I'm hoping to get permission to release the data once 
> there are some results that are closer to "research quality."  (We have been 
> collecting data continuously since early March.)
> -dpm
> -- 
>  David P. Maynard, Flametree Corporation
>  EMail: dpm at,  Tel: +1 512 670 4090,  Fax: +1 512 251 8308
> --

Art Houle     				e-mail:  houle at
Academic Computing & Network Services 	 Voice:  644-2592
Florida State University		   FAX:  644-8722

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