Extend an eligible Infoblox maintenance term by one year where the installation already has three or more years of maintenance. IB-MAIN-1550-A-NS1-03PLUS is an add-on maintenance service code, not a standalone network appliance. Its purpose is to add a defined one-year term to the applicable existing maintenance arrangement. The three-plus-year condition is central to selection. This service is intended for an environment with an established qualifying maintenance term rather than a deployment starting maintenance from scratch. Match the code to the applicable Infoblox product or service record and verify that the current maintenance arrangement satisfies the required duration before applying the extension. Use this add-on when a one-year increase is needed beyond a qualifying three-year-or-longer maintenance term. The service duration remains clearly defined at one year, helping maintain a consistent maintenance period for the covered Infoblox environment. It is distinct from appliance hardware because it represents maintenance coverage duration rather than a physical device, interface, capacity tier, or software feature set.