Very Imp_volte Call Flows 2ouv

APN Architecture

Highlighted bearers shown above in APN architecture are planned for future

INITIAL ATTACH UE1

eNodeB

MME

SGW&PGW/PCEFINTERNET APN

PCRF

HSS

UE Powers ON. Does initial LTE Attach. PCO includes DNS address

1. EMM: LTE Initial Attach; ESM Container: PDN Conn Request (PCO:IP-DNS) 2. Authentication: AIR/AIA 3. ULR 4. ULA (APN Config Profile: Default APN-INTERNET; Subscribed QoS QCI_9;Authorized: IMS APN; APN 5. Create Session Request 6. CCR: Framed_IP_Addr

7. Sp: Additional Authorized Profiles 8. CCA: Charging ID; QoS Info 9. Create Session Response

11a. RRC Connection Reconfig: IP address provided for INTERNET APN; PCO provides DNS address

11c. Direct Transfer

10. S1-AP Initial Context Setup Request (incl NAS for PDN Connectivity Request)

11b. S1-AP Initial Context Setup Response 11d. Attach Complete

12a. Modify Bearer Request 12b. Modify Bearer Response

At this stage, UE has established default bearer on INTERNET APN & E-RAB is setup

UE now transitions to Idle State; EMM ed/ECM & RRC Idle/ESM Active (SRB & DRB deleted)

Reestablish ECM/RRC states to Connected & reestablish E-RAB 13. RRC: SRB1 Reestablishment 14. NAS: Service Request 16. RRC Reconfiguration: Reestablish SRB2/ DRB1 UE1

15. ICS Request

eNodeB

MME

SGW&PGW/PCEFINTERNET APN

PCRF

HSS

ON-DEMAND APN UE1

eNodeB

MME

SGW&PGW/PCEFIMS APN

PCRF

HSS

CSCF/ TAS

HLR/IP VLR

UE is in CONNECTED state. Dialer invoked or also done on power-up 1. PDN Connectivity Request (IMS APN); (PCO:PCSCF Address) 2. Create Session Request 3. CCR: Framed_IP_Addr

4. Sp: Authorized QoS Profile (QCI:5)

5. CCA: Charging ID; QoS Info

6. Create Session Response

7. Bearer Setup Request

8. RRC Reconfig:Complete IP address provided for IMS APN & P-CSCF address provided

9. Bearer Setup Response

10. Direct Transfer 11. UL NAS Transport

12. Modify Bearer Request/Response

At this stage, UE has established a 2nd default bearer on IMS APN for VoIP signaling (QCI_5) & E-RAB is setup

13. IMS SIP Registration

14. FEATRE Q 15. QUALDIR

UE1

eNodeB

MME

SGW&PGW/PCEFIMS APN

PCRF

HSS

CSCF/ TAS

HLR/IP VLR

VoLTE-VOLTE cALL setup

SGW&PGW/ PCEF-IMS APN

O-CSCF/ TAS

UE1

T-CSCF/ TAS

PCRF

O-MGCF

UE2

T-MGCF

GMSC

SIP VoIP call initiated. Network Initiated Dedicated EPS Bearer Context Creation for SIP Signaling created on LTE Attach UE1 LTE Attach completed. ed in IMS

UE2 LTE Attach completed. ed in IMS

1. IMS: SIP INVITE ed: Preconditions, 100Rel, PEM; SDP1 (Offer) a=curr:qos local none;a=curr:qos remote none Orig P-CSCF will NOT generate AAR now – configuration to generate AAR only on SDP answer 2. IMS breaks out all calls

3. IMS: SIP INVITE ed: Preconditions, 100Rel, PEM; SDP1 (Offer) a=curr:qos local none;a=curr:qos remote none;

4. 183 Session Progress (SDP2 for Audio) a=curr:qos local sendrecv; a=curr:qos remote none; a=conf:qos, PEM: inactive

5a. AAR

O-MGCF will have allocated resources – so can set local end to sendrecv

5b. AAA

5c. RAR 5d. RAA 6. Dedicated Bearer Setup for UE1 (VoIP media/UM DRB/QCI_1)

5c. 183 Session

Rx & Gx signaling is NOT event based with current software. Metro requirement is to have event based signaling.

7a. CCR-U 7b. CCA-U

Progress (SDP2 for Audio) a=curr:qos local sendrecv; a=curr:qos remote none; a=conf:qos 8a. PRACK/200OK

O-MGCF has to hold off on sending IAM since Preconditions is ed (COT is not ed at MPCS)

Because of asynchronous Rx signaling, Gx signaling could be happening at same time as STEP “5c” 8b. PRACK/200OK

Resource Allocation Completed 9a. Update (SDP3 a=curr:qos local sendrecv; a=curr:qos remote sendrecv)

Since Rx & Gx signaling is not event based with current software, even more important that UPDATE is send ONLY after resource allocation is completed.

Orig P-CSCF will NOT generate AAR now – configuration to generate AAR only on SDP answer 9b. Update (SDP3 a=curr:qos local sendrecv; a=curr:qos remote sendrecv) Resource Allocation Completed – can happen anytime after receiving IAM

10a. 200OK (SDP4 a=curr:qos local sendrecv; a=curr:qos remote sendrecv)

10b. AAR 10c. AAA 10d. RAR 10e. RAA Because of asynchronous Rx signaling, Gx signaling could be happening at same time as STEP “10d”

Bearer Resource Modification without QoS Update 10d. 200OK (SDP4 a=curr:qos local sendrecv; a=curr:qos remote sendrecv)

UE1

O-CSCF/ TAS

10f. CCR-U 10g. CCA-U

11. IAM 12. HLR/TAS interaction to get TLDN (IMRN) SGW&PGW/ PCEF-IMS APN

PCRF

T-CSCF/ TAS

UE2

O-MGCF

T-MGCF

GMSC

UE1

O-CSCF/ TAS

VoLTE-VOLTE cALL setup – Cont.. SGW&PGW/ PCEF-IMS APN

T-CSCF/ TAS

PCRF

UE2

O-MGCF

T-MGCF

14. IMS: SIP INVITE TLDN ed: Preconditions, 100Rel, PEM; SDP5 (Audio) a=curr:qos local sendrecv;a=curr:qos remote none;

GMSC

13. IAM (TLDN)

Setting on MGCF to have Preconditions set for outgoing SIP trunks Term P-CSCF will NOT generate AAR now – configuration to generate AAR only on SDP answer

This INVITE has local sendrecv & remote none since MGCF is acting as UAC and has reserved bearer ports on MGW

15. IMS: SIP INVITE UE2 MSISDN Require: Preconditions, 100Rel, PEM; SDP5 (Audio) a=curr:qos local sendrecv;a=cur r:qos remote none;

17a. AAR Rx & Gx signaling is NOT event based with current software. Metro requirement is to have event based signaling.

17c. RAR

Resource Allocation Completed – can happen anytime after receiving IAM

16. 183 Session Progress (SDP6 for Audio) a=curr:qos local none; a=curr:qos remote sendrecv; PEM: inactive; a=conf:qos

17b. AAA

17d. RAA 18. Dedicated Bearer Setup for UE2 (VoIP media/UM DRB/QCI_1)

Because of asynchronous Rx signaling, Gx signaling could be happening at same time as STEP “17c”

19a. CCR-U

17c. 183 Session Progress (SDP6 for Audio)

19b. CCA-U

a=curr:qos local none; a=curr:qos remote sendrecv; PEM: inactive; a=conf:qos

20a. PRACK/200OK 20b. PRACK/ 200OK

21a. Update (SDP7 a=curr:qos local sendrecv; a=curr:qos remote none) Term P-CSCF will NOT generate AAR now – configuration to generate AAR only on SDP answer 21b. Update (SDP7 a=curr:qos local sendrecv; a=curr:qos remote none)

UE1

O-CSCF/ TAS

SGW&PGW/ PCEF-IMS APN

PCRF

T-CSCF/ TAS

UE2

O-MGCF

T-MGCF

GMSC

UE1

O-CSCF/ TAS

VoLTE-VOLTE cALL setup – Cont..

SGW&PGW/ PCEF-IMS APN

PCRF

T-CSCF/ TAS

O-MGCF

UE2

T-MGCF

GMSC

Resource Allocation Completed

Since Rx & Gx signaling is not event based with current software, even more important that 200OK is send ONLY after resource allocation is completed.

22a. 200OK (SDP8 a=curr:qos local sendrecv; a=curr:qos remote sendrecv)

23a. AAR 23b. AAA 24a. RAR 24b. RAA

25. Bearer Resource Modification without QoS Update 26a. CCR-U 24a. 200OK (SDP8 a=curr:qos local sendrecv; a=curr:qos remote sendrecv)

26b. CCA-U Because of asynchronous Rx signaling, Gx signaling could be happening at same time as STEP “24a”

Anytime after Step 22a: 180 Ringing (No SDP); PEM: inactive Alert 180 Ringing (No SDP); PEM: inactive

Ring-back Tone generated by T-MGCF 23.ACM

24. ACM (sub-free)

Enable Early Media now for UE1

Since 180 Ringing and alerting of can happen anytime after Step 22a, could run into timing issue if UE2 answers the call before Step24 is completed. In this case UE2 will start talking but UE1 will not hear anything until early media is enabled, which happens only after Step24. There is no workaround for this behavior and is acceptable

180 Ringing (No SDP); PEM: sendonly

180 Ringing (No SDP); PEM: sendonly Answer Call

Since PEM is sendonly, no local Ringback generated on receiving 180 Ringing

200OK 200OK ANM

ACK

ACK

26. ANM

200OK

200OK

ACK

ACK

UE1

O-CSCF/ TAS

SGW&PGW/ PCEF-IMS APN

PCRF

T-CSCF/ TAS

UE2

O-MGCF

T-MGCF

GMSC

CALL TEARDOWN UE1

eNodeB

MME

SGW&PGW/PCEFIMS APN

PCRF

CSCF/ TAS

UE2

MGCF

GMSC

BYE

BYE

REL RLC

BYE BYE 200OK STR STA

200OK

RAR

RAA

Dedicated Bearer Deleted for UE1

CCR-T CCA-T

Following steps can be happening in parallel with Gx messaging on the 1st call leg 200OK STR STA

RAR 200OK RAA

Dedicated Bearer Deleted for UE2

CCR-T CCA-T

UE1

eNodeB

MME

SGW&PGW/PCEFIMS APN

PCRF

CSCF/ TAS

UE2

MGCF

GMSC

cALL setup – VoLTE to CS/PSTN SGW&PGW/ PCEF-IMS APN

O-CSCF/ TAS

VoLTE

T-CSCF/ TAS

PCRF

O-MGCF

Terminator

SIP VoIP call initiated. Network Initiated Dedicated EPS Bearer Context Creation for SIP Signaling created on LTE Attach UE1 LTE Attach completed. ed in IMS 1. IMS: SIP INVITE ed: Preconditions, 100Rel, PEM; SDP1 (Offer) a=curr:qos local none;a=curr:qos remote none Orig P-CSCF will NOT generate AAR now – configuration to generate AAR only on SDP answer O-MGCF has to hold off on sending IAM since Preconditions is ed (COT is not ed at MPCS)

2. IMS breaks out all calls

3. IMS: SIP INVITE ed: Preconditions, 100Rel, PEM; SDP1 (Offer) a=curr:qos local none;a=curr:qos remote none

4. 183 Session Progress (SDP2 for Audio) a=curr:qos local sendrecv; a=curr:qos remote none; a=conf:qos; PEM: inactive

5a. AAR

Resource Allocation Completed

O-MGCF will have allocated resources – so can set local end to sendrecv

5b. AAA

5c. RAR 5d. RAA

Because of asynchronous Rx signaling, Gx signaling could be happening at same time as STEP “5c”

6. Dedicated Bearer Setup for VoLTE UE (VoIP media/UM DRB/QCI_1)

5c. 183 Session

7a. CCR-U

Progress (SDP2 for Audio) a=curr:qos local sendrecv; a=curr:qos remote none; a=conf:qos

7b. CCA-U

8b. PRACK/200OK

8a. PRACK/200OK Resource Allocation Completed 9a. Update (SDP3 a=curr:qos local sendrecv; a=curr:qos remote sendrecv)

Since Rx & Gx signaling is not event based with current software, even more important that UPDATE is send ONLY after resource allocation is completed.

Orig P-CSCF will NOT generate AAR now – configuration to generate AAR only on SDP answer 9b. Update (SDP3 a=curr:qos local sendrecv; a=curr:qos remote sendrecv) 10a. 200OK (SDP4 a=curr:qos local sendrecv; a=curr:qos remote sendrecv)

10b. AAR 10c. AAA

11. IAM

10d. RAR

Call is delivered to Terminating side

10e. RAA 10f. Bearer Resource Modification without QoS Update 12.Ringback Tone generated by Terminating side

10d. 200OK (SDP4 a=curr:qos local sendrecv; a=curr:qos remote sendrecv)

10g. CCR-U 12. ACM (sub-free)

10h. CCA-U

Enable Early Media now for UE1

Because of asynchronous Rx signaling, Gx signaling could be happening at same time as STEP “10d”

14. 180 Ringing (No SDP); PEM: sendonly

13. 180 Ringing (No SDP); PEM: sendonly

Since PEM is sendonly, no local Ringback generated on receiving 180 Ringing

15. ANM 16a. 200OK

16b. 200OK 17a. ACK VoLTE

17b. ACK O-CSCF/ TAS

SGW&PGW/ PCEF-IMS APN

PCRF

T-CSCF/ TAS

O-MGCF

Terminator

cALL setup – CS/PSTN to VoLTE SGW&PGW/PCEF-IMS APN

PCRF

T-MGCF

VoLTE UE

T-CSCF/TAS

GMSC

HLR/TAS interaction to get TLDN (IMRN) 1. IAM (TLDN)

2. IMS: SIP INVITE TLDN ed: Preconditions, 100Rel, PEM; SDP1 (Audio) a=curr:qos local sendrecv;a=curr:qos remote none Setting on MGCF to have Preconditions set for outgoing SIP trunks Term P-CSCF will NOT generate AAR now – configuration to generate AAR only on SDP answer

This INVITE has local sendrecv & remote none since MGCF is acting as UAC and has reserved bearer ports on MGW

3. IMS: SIP INVITE UE2 MSISDN ed: Preconditions, PEM, 100Rel; SDP1 (Audio) a=curr:qos local sendrecv ;a=curr:qos remote none

5. AAR

7. RAR

Resource Allocation Completed – can happen anytime after receiving IAM

4. 183 Session Progress (SDP2 for Audio) a=curr:qos local none; a=curr:qos remote sendrecv; PEM: Not Authorized; a=conf:qos

6. AAA

8. RAA 9. Dedicated Bearer Setup for VoLTE UE (VoIP media/UM DRB/QCI_1)

Because of asynchronous Rx signaling, Gx signaling could be happening at same time as STEP “7”

10a. CCR-U

7. 183 Session Progress (SDP2 for Audio) 10b. CCA-U

a=curr:qos local none; a=curr:qos remote sendrecv; PEM: inactive; a=conf:qos 11a. PRACK/200OK 11b. PRACK/200OK 12a. Update (SDP3 a=curr:qos local sendrecv; a=curr:qos remote none) Term P-CSCF will NOT generate AAR now – configuration to generate AAR only on SDP answer 12b. Update (SDP3 a=curr:qos local sendrecv; a=curr:qos remote none) Resource Allocation Completed

13b. AAR

14a. RAR

13a. 200OK (SDP4 a=curr:qos local sendrecv; a=curr:qos remote sendrecv)

13c. AAA

Since Rx & Gx signaling is not event based with current software, even more important that 200OK is send ONLY after resource allocation is completed.

Because of asynchronous Rx signaling, Gx signaling could be happening at same time as STEP “14a”

14b. RAA 15. Bearer Resource Modification without QoS Update 16a. CCR-U

14a. 200OK (SDP5 a=curr:qos local sendrecv; a=curr:qos remote sendrecv)

16b. CCA-U

Anytime after Step 13a: 180 Ringing (No SDP); PEM: inactive Alert Ringback Tone generated by T-MGCF

180 Ringing (No SDP); PEM: inactive

Answer Call

ACM

200OK

ANM ACK SGW&PGW/PCEF-IMS APN

PCRF

T-CSCF/TAS

VoLTE UE

T-MGCF

GMSC