Support of SHAKEN for TollFree Calls Chris Wendt

Support of SHAKEN for Toll-Free Calls Chris Wendt David Hancock 1

Problem discovered during testing w ATIS test-bed • Traditionally, TFN routing via TCAP required two database dips • Dip in originating network returns CIC • Originating network routes call to terminating network identified by CIC • Terminating network does 2 nd database dip to get TFN routing number • TFN routing is migrating to SIP-based single dip mechanism • TFAS TFN routing database dip in originating network returns routing number • Question: Does SHAKEN need to support all of these cases, and if so, how? 2

TFN Routing: single SIP database dip in orig network returns TFN routing number Originating SP-a TN-a UE STI-AS CSCF [1] INVITE 1 -800… To: 1 -800…; PAID: TN-a; Date: t TFAS CSCF, Etc. [2] INVITE TN: 1 -800…@sp-a. com To: 1 -800…; PAID: TN-a; Date: t [3] INVITE 1 -800…@sp-a. com To: 1 -800…; PAID: TN-a; Date: t Identity: PASSpor. T token orig/dest/iat=a/1800…/t Update INVITE Request-URI and To: header with routing number Terminating SP-b [4] INVITE 1 -800… To: 1 -800…; PAID: TN-a; Date: t Identity: PASSpor. T token orig/dest/iat=a/1800…/t [5] 302 Moved Temporarily Contact: sip: 12125551212@sp-b. com Discard old Identity header and Re-authenticate [6] INVITE sip: 12125551212@sp-b. com To: 12125551212; PAID: TN-a; Date: t Identity: PASSpor. T token orig/dest/iat=a/12125551212/t STI Verification Pass 3

TFN Routing: TCAP double database dip User A SP-a Perform SHAKEN Authentication [1] INVITE sip: +18005551212@spa. com To: sip: +18005551212@spa. com; From: TN-a; Date: t SCP [2] TCAP Query 1 -800. . . [3] cic: <1234> Route call based on returned CIC value In this case, CIC "1234" translates to SP-B SP-c SP-b Perform SHAKEN Verification [4] INVITE sip: +18005551212; cic: 1234@spb. com To: sip: +18005551212@spa. com; From: TN-a; Date: t Identity: shaken PASSpor. T token { orig/dest/iat=a/1800…/t} SCP [5] TCAP Query 1 -800. . . [6] routing number: 19094561234 Route call based on routing number. In this example, 19094561234 belongs to SP-c (domain spc. com). [7] INVITE sip: +19094561233@sp-c. com To: sip: +18005551212@spa. com; From: TN-a; Date: t Identity: shaken PASSpor. T token { orig/dest/iat=a/1800…/t} div PASSpor. T token { orig/dest/iat=a/1909…/t}

TFN Routing: mixed TCAP/SIP double database dip User A SP-a Perform SHAKEN Authentication SCP [1] INVITE sip: +18005551212@spa. com To: sip: +18005551212@spa. com; From: TN-a; Date: t [2] TCAP Query 1 -800. . . [3] cic: <1234> Route call based on returned CIC value In this case, CIC "1234" translates to SP-B SP-c SP-b Perform SHAKEN Verification [4] INVITE sip: +18005551212; cic: 1234@spb. com To: sip: +18005551212@spa. com; From: TN-a; Date: t [5] INVITE 1 -800. . . Identity: shaken PASSpor. T token { orig/dest/iat=a/1800…/t} TFAS [6] 302 Moved Temporarily Authenticate Route call based on routing number. In this example, 19094561234 belongs to SP-c (domain sp-c. com). Contact: sip: 18094561234@sp-b. com Identity: shaken PASSpor. T token div PASSpor. T token [7] INVITE sip: +19094561233@sp-c. com To: sip: +18005551212@spa. com; From: TN-a; Date: t Identity: shaken PASSpor. T token { orig/dest/iat=a/1800…/t} div PASSpor. T token { orig/dest/iat/div=a/1909…/t/1800…}