Application Type / Interface Matrix Reference Bandwidth Management Applications Standards Reference Point SBC as External Policy Server as Protocol Interface TISPAN P-CSCF A-RACF Diameter Rq 3GPP (R15) P-CSCF PCRF Diameter Rx 3GPP (R6) P-CSCF (AF) PDF Diameter Gq Packet Cable P-CSCF (AF) PDF COPS PKT-MM3 N/A N/A RACF ACME COPS N/A Emergency Location Services Standards Reference Point SBC as External Policy Server as Protocol Interface N/A P-CSCF CLF Diameter e2 N/A N/A CLF ACME COPS N/A