The Nicname protocol (Nicname) is also known as WhoIs. While the DNS servers store the actual Domain Name translation tables; Nicname servers store the unobscured human-readable database of IANA Domain Name leasee information, including contact information and lease period, provided by the Registrar (a potential privacy issue). Servers are accessed using a TelNet client.
ICANN has given rights to specific organizations to manage TLD registration, and these organizations operate Authoritive servers (including sometimes mirrored servers) where they keep the master database for each TLD under their jurisdiction. In order to make locating data easier, a number of Universities and other organizations operate their own servers, which aggregate the databases from each of these authoritive servers together into a single database. There can however be a significant delay from when the authoritive server posts data to when the aggregating server updates its database from the authoritive server. Below are addresses to both Authoritive and Aggregating public Nicname servers.
[IANA Port assignment = 43]