ATIS 1000010-2006 Support of Emergency Telecommunications Service ETS in IP Network.pdf

1、 AMERICAN NATIONAL STANDARD FOR TELECOMMUNICATIONS ATIS-1000010.2006(R2011) Support of Emergency Telecommunications Service (ETS) in IP Networks ATIS is the leading technical planning and standards development organization committed to the rapid development of global, market-driven standards for the

2、 information, entertainment and communications industry. More than 250 companies actively formulate standards in ATIS 18 Committees, covering issues including: IPTV, Service Oriented Networks, Energy Efficiency, IP-Based and Wireless Technologies, Quality of Service, and Billing and Operational Supp

3、ort. In addition, numerous Incubators, Focus and Exploratory Groups address emerging industry priorities including “Green”, IP Downloadable Security, Next Generation Carrier Interconnect, IPv6 and Convergence. ATIS is the North American Organizational Partner for the 3rd Generation Partnership Proje

4、ct (3GPP), a member and major U.S. contributor to the International Telecommunication Union (ITU) Radio and Telecommunications Sectors, and a member of the Inter-American Telecommunication Commission (CITEL). For more information, please visit . AMERICAN NATIONAL STANDARD Approval of an American Nat

5、ional Standard requires review by ANSI that the requirements for due process, consensus, and other criteria for approval have been met by the standards developer. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly

6、and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made towards their resolution. The use of American National Standards is comp

7、letely voluntary; their existence does not in any respect preclude anyone, whether he has approved the standards or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standards. The American National Standards Institute does not develop

8、standards and will in no circumstances give an interpretation of any American National Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American National Standard in the name of the American National Standards Institute. Requests for interpretations sh

9、ould be addressed to the secretariat or sponsor whose name appears on the title page of this standard. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken periodically to rea

10、ffirm, revise, or withdraw this standard. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute. Notice of Disclaimer Basic (“GETS-like”) authentication mechanisms and procedures; and Security requir

11、ements. ETS is a forward-looking service that requires priority treatment in the IP network infrastructure in support of National Security/Emergency Preparedness (NS/EP) communications. ETS has capabilities to increase the probability of successful completion of calls, sessions, or other communicati

12、ons initiated by government authorized users over the public network infrastructure. ETS also includes legacy circuit-switched NS/EP services such as Government Emergency Telecommunications Service (GETS) and Wireless Priority Service (WPS)1. This document includes end-to-end ETS call flows that ill

13、ustrate calls originating and terminating on: IP access (e.g., cable or DSL); narrowband wireline access (e.g., POTS phone); and wireless access (e.g., GSM or CDMA phone); that traverse through IP and circuit-switched Core Networks. A service description of ETS is contained in the ATIS Technical Rep

14、ort (TR), Service Description of ETS ANSI-1000005. The ETS and WPS procedures previously defined for circuit-switched wireline ANSI-1000006.2005 and wireless ANSI TIA-917, 3GPP TR 22.952 technologies, respectively, are not impacted by this document. 1TIA uses the term “Wireless Priority Service,” wh

15、ereas 3GPP uses the term “Priority Service”. ATIS-1000010.2006 2 2 ABBREVIATIONS Technical Specification Group Services and System Aspects; Priority service guide; (Release 6).64 FUNCTIONAL REFERENCE MODEL Figure 1 illustrates the functional reference model for the support of ETS in IP networks. Thi

16、s is the same model as used for the IP-IP NNI between two interconnecting service providers. It consists of a signaling interface and a bearer interface. The signaling and bearer interfaces support the flow of information among the following IP network logical entities: Call Routing Functional Entit

17、y (CRFE), Call Control Functional Entity (CCFE), and Bearer Functional Entity (BFE), as defined in ATIS-1000009.2006. In support of ETS in IP networks, the ETS specific information (e.g., ETS call marking, calling users priority level) needs to be signaled across the IP-IP NNI between two interconne

18、cting VoIP providers. Support of the end-to-end ETS service requires the interworking of ETS specific information between the IP technology domain and other technology domains (e.g., wireless or wireline TDM domains). 6This document is available from the Third Generation Partnership Project (3GPP) a

19、t . ATIS-1000010.2006 IP PhoneIP PhonePSTNPSTNBearerSignalingCCFE: Call Control FEBFE: Bearer FECRFE: Call Routing FEMG: Media GatewayProviderBVoIPProviderAVoIPLogical InterfacesCRFECRFECCFEBFE BFEWireless/MobileRadio Access NetworkWireless/MobileRadio Access NetworkCCFEFigure 1 - ETS in IP Networks

20、 Reference Model 8 ATIS-1000010.2006 C1-TDMC2-TDMC2-IPC1-IPCORE NetworksNote: A core network is the authenticating network, a transit network, or bothWSNWIPWSNWIPOriginatingAccessTerminatingAccessWS Wireless AccessNW Narrowband Wireline AccessFigure 2 - End-to-End Call Matrix Figure 2 is an end to e

21、nd call matrix for the call flows illustrated in this document. It illustrates calls: Originating and terminating on IP (e.g., Cable and DSL), narrowband wireline (e.g., POTS phone), and wireless (e.g., GSM and CDMA phone) access; and Traversing through IP and circuit-switched (TDM) Core Networks. T

22、he call/session scenarios associated with Figure 2 can be found in clause 6. An ETS call may be initiated by dialing an ETS-specific DN, called ETS-DN in this standard. A WPS call is a call dialed using a WPS-Feature Code (WPS-FC). A WPS call is treated as a specific type of ETS call. When the calli

23、ng party dials a WPS-FC+ETS-DN, the call is treated both as a WPS call and an ETS call. In particular, the call is subject to both WPS and ETS authentication. 9 ATIS-1000010.2006 10 5 EMERGENCY TELECOMMUNICATIONS SERVICE IN IP NETWORKS 5.1 Assumptions and General Principles 5.1.1 Assumptions 1. With

24、in an IP domain, an ETS call/session is assigned one of five user priority levels associated with the calling service user. 2. SIP messages are only processed by SIP proxies/UAs, and therefore the SIP Resource Priority Header (RPH) is not processed by IP transport elements (e.g., routers). 3. Two ty

25、pes of core networks are considered in this standard: IP and TDM. 4. Three different originating and terminating access types are considered in this standard: wireline IP (e.g., DSL, cable), wireline TDM, and wireless. 5. An NS/EP call/session can traverse multiple IP and TDM core networks. 6. An ET

26、S call originating over an IP access is authenticated either in an IP or a TDM core network. A WPS call is authenticated by the wireless service provider network of the calling party. IP-based wireless authentication (e.g., for UMTS) is not addressed in this document. 7. If both WPS and ETS authenti

27、cation occur (i.e., the calling user dials WPS-FC+ETS-DN), the WPS authentication - at the wireless access - occurs before the ETS authentication. 8. If the authentication process identifies a user priority, both the ets and wps namespaces may be set to the same priority values. The wps namespace re

28、flects the actual user priority. 9. The service providers managed access and core networks are secure. 10. The DTMF tones are carried across an IP core network in accordance with RFC 4733, RTP Payload for DTMF Digits, Telephony Tones and Telephony Signals. 5.1.2 General Principles 1. Two types of au

29、thentication functions are considered in this document. ETS authentication This type of authentication is invoked when the calling user dials an ETS-DN. i. If the call is authenticated in the TDM domain, after the call is authenticated: The CPC parameter in the IAM is set to “NS/EP Call.” Existing T

30、DM authentication mechanisms do not have the calling users priority value, so the Precedence parameter is not included in the IAM. If future authentication mechanisms have the calling users priority value, the Precedence parameter will be included in the IAM. ii. If the call is authenticated in the

31、IP domain, after the call is authenticated: If the calling users priority level is not available, only ets.x is created in the RPH, where x is a default priority value based on policy; or If the calling users priority level is available, both ets.x and wps.y namespaces are created in the RPH, where

32、y is the calling users priority level and x is based on policy. WPS authentication This type of authentication is invoked when the calling user dials a WPS-FC+DN. ATIS-1000010.2006 11 i. If the call is authenticated in the TDM domain, after the call is authenticated: The CPC parameter in the IAM is

33、set to “NS/EP Call.” If the calling users priority level is available, the Precedence level (in the Precedence parameter) in the IAM would also be set (precedence level 0 4 corresponding to user priorities 1 5). ii. WPS authentication in the IP domain (e.g., for UMTS phones) is not addressed in this

34、 document. Successful ETS authentication may result in changing the priority values in the ets or wps namespaces. 2. The ets priority level (x) of an ETS (including a WPS) call/session is carried in the SIP RPH namespace, “ets.x”, where x=4 to 0, where 0 is the highest priority. For a call traversin

35、g from a circuit-switched network to an IP network, the Ingress IP Gateway (IIP-GW) creates the SIP RPH ets namespace based on the presence of ETS-DN in the Called Party Number parameter, or the Calling Partys Category parameter coded as “NS/EP Call” in the received IAM. The IIP-GW assigns the ets p

36、riority level. It is mandatory for the IIP-GW to support a provisionable default value for the ets priority level. The default value for the ets priority level is determined by policy7. If no ISUP Precedence parameter is received, the default value is used to populate the ets priority level. If a Pr

37、ecedence parameter is received, then, based on policy, either the default value or the precedence level in the Precedence parameter is used to populate the ets priority level. An ETS Authentication Application Server (AS) may modify the value of the received ets priority level based on a successful

38、Authentication Verification Processing. An ETS Authentication AS deletes the received RPH if the authentication is denied. 3. A successfully authenticated WPS call/session includes the RPH with the ets namespace. In addition to the ets.x, the RPH for a successfully authenticated WPS call/session con

39、tains the “wps.y” namespace with the priority level (y) associated with the calling WPS user. For a WPS call/session traversing from a circuit-switched network to an IP network, the IIP-GW maps the precedence level in the received Precedence parameter to the priority value in the wps namespace. The

40、precedence level is determined during authentication of the WPS user.The presence of the ets namespace indicates an ETS or a WPS call/session and triggers priority treatment. However, the priority value (x) in the “ets.x” may be used for priority treatment only in the IP domain and is not used for p

41、riority treatment on the wireless access. The wps namespace value (y) is used for priority treatment on the wireless access. 4. The wps.y namespace is transported through the IP domain to facilitate priority treatment on the wireless access. An ETS Authentication Application Server (AS) may modify a

42、 received wps priority level, or - if a wps namespace is not received - create a wps namespace based on Authentication Verification Processing. For a call traversing from an IP network to a circuit-switched network, the Egress IP Gateway (EIP-GW) shall use the priority level in the wps namespace, if

43、 present, to populate the precedence level of the Precedence parameter in the outgoing ISUP IAM. 7The policy will be determined by the NCS. The same policy will be applicable to all concerned service providers in a given scenario. ATIS-1000010.2006 12 For a call traversing from an IP network to a ci

44、rcuit-switched network, if the ets.x namespace is present but the wps.x namespace is not present, the EIP-GW shall not send the Precedence parameter in the outgoing ISUP IAM. 5. Processing of ETS calls/sessions, including the associated signaling and media, are provided priority treatment over non-E

45、TS calls based on the presence of ets.x. 6. The ets.x RPH priority value may be used for priority treatment of ETS traffic at certain interfaces, such as IP access-to-core and IP network-to-network interfaces, where connection admission control may be applied. 7. The ets.x RPH priority value may be

46、used by SIP proxies and B2BUAs to make routing decisions, particularly on IP access. 8. Based on policy, the Session Border Control function (CCFE and BFE) facing a user may modify a received RPH ets priority level with the provisioned default value. 9. All packets associated with an ETS call/sessio

47、n must receive priority handling: i. In network element queues, ii. For access to the IP backbone, and iii. Within the IP backbone. This priority handling is based on the presence of an ets namespace in an RPH. 10. A secure mechanism that validates the identity of the far end sending network is requ

48、ired in order to support priority handling of packets on an IP-NNI. 5.2 Protocol Behavior The procedures in this document only apply to supporting ETS in IP Access and Core Networks, including interworking with circuit-switched systems. The ETS and WPS procedures previously defined for circuit-switc

49、hed wireline ANSI-1000006.2005 and wireless ANSI TIA-917 technologies respectively are not impacted by this document, and therefore will only be referenced. 5.2.1 Protocol Mappings 5.2.1.1 ISUP to SIP Mappings Table 1 shows the mapping from ISUP to SIP for ETS related information. ATIS-1000010.2006 13 Table 1 - ISUP to SIP Mappings ISUP SIP CdPN = Destination Number CPC not equal to NS/EP Call No PRECEDENCE PARAMETER This is a normal (non-ETS) call R-URI/To: = Destination Number CdPN = ETS-DN CPC = NS/EP Ca