ISO/IEC TR 16167:2011 discusses issues related to emergency calls from an enterprise user to a safety answering point (SAP) using the Session Initiation Protocol (SIP) within a Next Generation Corporate Network (NGCN). A SAP can be either a public safety answering point (PSAP) or a private emergency answering point (PEAP). ISO/IEC TR 16167:2011 uses terminology and concepts developed in ISO/IEC TR 12860. It identifies a number of requirements impacting Next Generation Network standardization and concerning deployment of enterprise networks. The scope of ISO/IEC TR 16167:2011 is limited to calls from a user of an enterprise network to an authority, where the authority is represented by a SAP (PSAP or PEAP). This includes the special case where a PEAP acts as an enterprise user in making an emergency call to a PSAP. Authority to authority calls, authority to enterprise user calls and enterprise user to enterprise user calls within the context of an emergency are out of scope, with the exception of return calls and verification calls as follow-up to an emergency call from the user to an authority.