Q. I would like to have my company listed on the map. How do I go about it?
A. You have to either be a member of the Internet Service Providers' Association, or, providing upstream connectivity to an ISPA member, in order to be listed.

If you are an ISPA-member and are not listed, please email updates @

Q. How can I get my company logo displayed on the map?
A. You need to supply us your logo in PNG format, 152 x 50 pixels and make a donation towards the upkeep of the map by an amount of R3000+VAT per annum (or more if you so chose). Please email updates @ for further details or to make arrangements.

Q. How do I get de-listed?
A. Send an e-mail to updates @ ispmap . org . za.

Q. How often is the map updated? When will it next be updated?
A. At the leisure and discretion of the author!

Q. How do you determine an ISP's upstream connectivity?
A. Larger ISPs have a unique routing identifier called an autonomous system number (ASN) and/or their own IP address allocation. Using various looking glass sites world-wide, routing information is searched to determine which autonomous systems provide transit connectivity for the ISP in question. The names of the associated upstream ISP's are then looked up from the whois database of the regional internet registry that assigned the ASN.

In the case of smaller ISPs, lookups are done on the IP addresses of the ISP's web servers and MX (mail host) for their domain and traceroutes are done to these IP's to determine how they are connected.

Q. Why do you only show transit and not local peering/interconnection links?
A. Interconnection links do not follow clear hierarchical layers. Consequently, they would be extremely difficult to show on the map without excessive clutter and overlapping of lines and labels. This would reduce legibility and increase complexity.

There are also technical limitations in the software being used to generate the image that make it difficult or impossible to have both hierarchical and non-hierarchical links in the same diagram.

Q. What software do you use to generate the map?
A. The web-site is based on custom coded scripts, developed in PHP, which provide a facility to maintain a MySQL database with all the relevant ISP contact and connectivity details.

The custom scripts generate a dotfile from the database which is fed into Graphviz visualisation software, which in turn generates both the graphical map and the co-ordinates for the clickable image map.

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Copyright © Gregory Massel, 1995 to 2008.