An object of the invention is to associate a DID/public or non-DID/private telephone number and/or reachable location information with a SIP Enabled Device. More specifically, an embodiment of the invention is directed to providing an additional data parameter comprising alphanumeric data, as a "Display_ID" parameter. The parameter includes information including a DID/public telephone number non-DID/private number and/or location information that is specific to the SIP user endpoint and is different from the SIP URI host address/user information (terminal name and/or terminal number). In another embodiment, a first SIP Enabled Device accesses the local Display_ID and includes the Display_ID in a communication request. A second SIP Enabled Device is capable of processing the incoming communication request, extracting the Display_ID parameter, and displaying the Display_ID associated with the first SIP Enabled Device on the text display of the second SIP Enabled Device.