1. Introduction

   This document describes the specifications for the NSI Registry
   Registrar Protocol (RRP) version 1.1.0, a TCP-based, 7-bit US-ASCII
   text protocol that permits multiple registrars to provide second
   level Internet domain name registration services in the top level
   domains (TLDs) administered by a TLD registry. RRP is specified using
   Augmented Backus-Nauer Form (ABNF) as described in [ABNF]. Note that
   all ABNF string literals are case-insensitive and the examples
   provided in this document may use mixed case to improve readability.

   RRP was developed by the Network Solutions, Inc. Registry under the
   auspices of the Shared Registration System program. The protocol was
   initially deployed in April 1999 as part of a test bed implementation
   of the Shared Registration System with five registrars. Additional
   registrars began using the protocol in July 1999. The operational
   experiences of both the registry and the registrars identified
   several "lessons learned" which have been documented here as "Known
   Issues".

   This document provides both a description of a protocol and notice of
   learned operational issues that may be useful as first steps in
   developing a standards track domain registration services protocol.
   This document and the protocol it describes may be modified in the
   future based on continued operational experience and community
   reaction.

   The registry stores information about registered domain names and
   associated name servers. A domain name's data includes its name, name
   servers, registrar, registration expiration date, and status. A name
   server's data includes its server name, IP addresses, and registrar.
   A registrar MAY perform the following registration service procedures
   using RRP:

   - Determine if a domain name has been registered.
   - Register a domain name.
   - Renew the registration of a domain name.
   - Cancel the registration of a domain name.
   - Update the name servers of a domain name.
   - Transfer a domain name from another registrar.
   - Examine the status of domain names that the registrar has
     registered.
   - Modify the status of domain names that the registrar has
     registered.
   - Determine if a name server has been registered.
   - Register a name server.
   - Update the IP addresses of a name server.

   - Delete a name server.
   - Examine the status of name servers that the registrar has
     registered.

   All RRP commands include features to provide idempotency.  That is,
   the effect of each command is the same if the command is executed
   once or if the command is executed multiple times. This property is
   extremely useful in situations when a command is retried due to an
   error condition that results in a missed command response and a
   command retry is attempted. Command retries will be caught by the
   System and rejected with an appropriate error response code. Command
   parameters that do not provide idempotency will be explained fully as
   part of the appropriate command description.