However, it should also be possible to build a simple server that meets the minimum requirement for devices by delivering nearly static configuration content. These functional groups are intended only to provide a means to think about and organize the requirements. They are not required to be discrete steps, and they do not dictate a specific model. Once the network configuration has been resolved using either DHCP or some static method, the first problem for a new SIP user agent to solve is where to get its configuration. There are a number of well- defined ways to resolve this configuration service discovery problem.
Most existing solutions are trivial to implement, although each has pros and cons.
It is likely that a number of the existing solutions should be supported to perform this function as either the network environment or administration may dictate which solutions will work or be allowed. A device MUST be able to determine where to retrieve its configuration without manual provisioning. The next operation that a new device in the network must perform is to register with the configuration server. The server may require notification of a device s presence in order to create a new set of configuration data values, allocate resources, etc. A device that is new to the configuration domain MUST make the configuration server aware of its presence before it can retrieve configuration data for the first time.