RFC 1291 (rfc1291) - Page 3 of 10
Mid-Level Networks Potential Technical Services
Alternative Format: Original Text Document
RFC 1291 Potential Technical Services December 1991 o Technical services o Experimental sites for testing and dissemination of new software and technology to end sites on the network In addition, the following services are mentioned briefly which are discussed in detail elsewhere [SSM91, ML91]: o Network Operation services and the interaction between different mid-level networks in this area o Network Information services 3. Technical Services The Internet has grown to be an essential entity because of the services that it offers to its end users. The list of services is long and growing, but some services are more widely used and deployed than others. This section attempts to list and discuss those technical services that could help a mid-level network provide robust and improved services to its end sites. 3.1 Domain Name Service According to the NSFnet traffic statistics collected for May 1991, about 7% of the packets on the NSFnet backbone were domain nameserver (DNS) packets. This is a significant amount of traffic, and since most of the other network applications depend on this service, a robust DNS service is critical to any Internet site. Proper location of secondary nameservers so that they are located on different physical networks can increase the reliability of this service to a large extent [MOC87a, MOC87b]. However, the nature of the service requires that the nameservers for the next highest level be available in order to resolve names outline-mode side of one's domain. Thus, for "foo.princeton.edu" to resolve "a.mid.net", the root nameservers which point to mid.net's nameservers have to be reachable. To make the service more reliable, the mid-level network could have at least one nameserver that is able to resolve nameserver queries for all domains directly connected to it. Thus, in the event that the entire mid-level network becomes isolated from the rest of the Internet, applications can still resolve queries for sites directly connected to the mid-level network. Without this functionality, there is no way of resolving a name if the root (or higher level) nameservers become unreachable, even if the query is for a site that is directly connected and reachable. Aggarwal
