Section: 19.4.3 Service and Protocol service names for 3GPP
Content: A list of standardized "service-parms" names is required to identify a "service" as defined in clause 6.5 of IETF RFC 3958 [74]. The following table defines the names to be used in the procedures specified in 3GPP TS 29.303[ Domain Name System Procedures; Stage 3 ]  [73]: Table 19.4.3.1: List of 'app-service' and 'app-protocol' names NOTE 1: The formats follow the experimental format as specified in IETF RFC 3958 [74]. For example, to find the S8 PMIP interfaces on a PGW the Service Parameter of "3gpp-pgw:x-s8-pmip" would be used as input in the procedures defined in IETF RFC 3958 [74]. NOTE 2: Currently 'app-service' names identify 3GPP node type and 'app-protocol' identify 3GPP interfaces, which differs from more common usage of S-NAPTR where app-protocol is used for transport protocol. Type of nodes (i.e PGW, SGW, SGSN, MME, MSC Server etc) and interfaces (i.e. S11, S5, S8, Sv, etc.) follow the standard names from 3GPP TS 23.401[ General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access ]  [72] ,3GPP TS 29.060[ General Packet Radio Service (GPRS); GPRS Tunnelling Protocol (GTP) across the Gn and Gp interface ]  [6] and3GPP TS 23.216[ Single Radio Voice Call Continuity (SRVCC); Stage 2 ]  [92] with prefix "x-" added. NOTE 3: x-gn denotes an intra-PLMN interface using GTPv1-C, x-gp denotes an inter-PLMN interface using GTPv1-C. NOTE 4: The app-service of x-3gpp-pgw with app-protocols x-gn or x-gp identifies the co-located GGSN function on a PGW. The app-service of x-3gpp-ggsn with app-protocols x-gn or x-gp identifies a GGSN function that is not co-located with a PGW. NOTE 5: The app-service of x-3gpp-msc with app-protocol x-sv identifies the MSC Sv interface service. NOTE 6: The app-service of x-3gpp-amf with app-protocol x-n2 identifies the AMF N2 interface service. The app-service of x-3gpp-amf with app-protocol x-n26 identifies the AMF N26 interface service.