Overview

The Proxy CSCF (P-CSCF) is the first contact point within the IM CN subsystem for subscribers in an IMS network. A P-CSCF is allocated to the IMS terminal during IMS registration and does not change for the duration of the registration. From a standards perspective, the P-CSCF behaves like a SIP Proxy, i.e. it accepts requests and services them internally or forwards them on. The P-CSCF also behaves as a User Agent in some cases, i.e. in certain conditions it may terminate and/or independently generate SIP transactions. Examples of these cases are when the P-CSCF requests the registrar for a user’s registration state updates, when performing P-CSCF initiated dialog-release etc.


IMPORTANT

Ribbon recommends using the Transparency Profile to configure transparency on the SBC Core for new deployments, as well as applying additional transparency configurations to existing deployments. Do not use IP Signaling Profile flags in these scenarios because the flags will be retired in upcoming releases.

Refer to the SBC SIP Transparency Implementation Guide for additional information.

Figure 1: SBC Deployed as P-CSCF


At a high level, the functions performed by the P-CSCF are:

  • Forward the SIP REGISTER request received from the UE to an entry point determined using the home domain name, as provided by the UE
  • Forward SIP messages (other than REGISTER) received from the UE to the S-CSCF whose name the P-CSCF has received as a result of the registration procedure
  • Maintain mapping between the SIP URI for the subscriber and physical UE IP address as well as a Security Association between itself and each UE, for both authentication and confidentiality
  • Forward SIP requests or responses from the IMS core to the UE
  • Authorization of bearer resources and QoS management using the DIAMETER Rx interface to query an PCRF element
  • Ensure that the SIP messages received from the UE to the S-CSCF contain the correct or up to date information about the access network type currently used by the UE, when the information is available from the access network
  • Perform SIP message compression/decompression
  • Detect and handle an emergency session establishment request from the UE
  • Generation of CDRs

In IMS networks, the P-CSCF interfaces with the following other functional elements:

  1. S-CSCF over Mw interface (SIP)
  2. I-CSCF over Mw interface (SIP)
  3. IBCF over Mx interface (SIP)
  4. PCRF over Rx interface (Diameter)
  5. CDF over Rf interface (Diameter)
Ribbon P-CSCF acts as a combined IMS Application Level Gateway (ALG) and  IMS Access Gateway.
Note

SBC Core products using the P-CSCF role support "b=AS" (application-specific bandwidth) to calculate audio bandwidth.

Call Flow

Figure 2: UE Registration Call Flow


A brief description of the call-flow is as follows:

  1. UE sends a REGISTER with Request-URI pointing to the home-domain.
  2. The Ribbon P-CSCF adds Path header (along with the supported, require header with path option-tag), P-Visited-Network-ID header. In case of IMS AKA authentication scheme, it adds integrity-protected parameter set to “no” to Authorization header. The P-CSCF forwards the REGISTER to one of the I-CSCF based on the resolution of FQDN in Request-URI header.
  3. IMS core (I/S-CSCF) challenges the REGISTER with a 401 response. In case of IMS AKA authentication scheme, the WWW-Authenticate header contains “ik” and “ck” parameters (along with other parameters).
  4. The P-CSCF deletes ik, ck parameters from WWW-Authenticate header before forwarding 401 response towards the UE.
  5. In case of IMS AKA, UE establishes the IPSec connection towards P-CSCF and sends the REGISTER with credentials over the IPSec connection.
  6. The  P-CSCF forwards REGISTER with credentials towards IMS core and adds Path, P-Visited-Network-ID headers as described above. It adds integrity-protected parameter set to “yes” to Authorization header. The P-CSCF forwards the REGISTER to one of the I-CSCF based on the resolution of FQDN in Request-URI header.
  7. IMS core (I/S-CSCF) responds to the REGISTER with a 200 OK response. The 200 OK response contains Path, Service-Route headers, and P-Associated-URI header.
  8. The P-CSCF stores Service-Route, P-Associated-URI headers before forwarding these to the UE over the IPSec connection. This completes a successful registration.
  9. After a successful registration, the P-CSCF subscribes to IP-CAN status towards PCRF over Rx interface, as depicted in the call-flow.
  10. After a successful registration, the P-CSCF subscribes to registration event package to learn the change in the registration state of the UE. This results in exchange of SUBSCRIBE-200 OK, NOTIFY-200 OK between P-CSCF and S-CSCF.
  11. Optionally, the UE also subscribes to registration event package. The SUBSCRIBE-200 OK, NOTIFY-200 OK between UE and S-CSCF are transparently relayed by the P-CSCF.
    Figure 3: UE Origination Call Flow

A brief description of the call-flow is as follows:

  1. UE-A originates a call by sending INVITE with SDP offer towards P-CSCF.
  2. The Ribbon P-CSCF extracts service information from the SDP offer (IP address of the down link IP flow(s), port numbers to be used, and so on) and forwards the service information to the PCRF over Rx interface. It indicates that only an authorization check of the service information is requested.
  3. The P-CSCF also over writes the received Route headers with the stored Route header set (that is formed based on the Service-Route headers received during registration). Based on the stored route set, the INVITE is forwarded to S-CSCF directly.
    1. If a P-Preferred-Identity header is received from UE, the P-CSCF compares the same with the SIP URI(s) present in P-Associated-URI header contents stores at the time of registration. If they match, the PPI header converted to P-Asserted-Identity header. Else, the top most of P-Associated-URI header contents is sent as P-Asserted-Identity header.
  4. After recieving the 183 response with SDP answer, the P-CSCF extracts service information from the SDP answer (IP address of the up link IP flow(s), port numbers to be used, and so on) and forwards the service information to the PCRF over Rx interface.
  5. The 183 response is forwarded to UE.

Configuring SBC Towards UE

The following profiles are configured:

Configuring Transparency Profile

set profiles services transparencyProfile TRANS_PROF_ACCESS sipHeader To
set profiles services transparencyProfile TRANS_PROF_ACCESS sipHeader From
set profiles services transparencyProfile TRANS_PROF_ACCESS sipHeader Path
set profiles services transparencyProfile TRANS_PROF_ACCESS sipHeader Accept
set profiles services transparencyProfile TRANS_PROF_ACCESS sipHeader Reason
set profiles services transparencyProfile TRANS_PROF_ACCESS sipHeader Server
set profiles services transparencyProfile TRANS_PROF_ACCESS sipHeader Warning
set profiles services transparencyProfile TRANS_PROF_ACCESS sipHeader Call-Info
set profiles services transparencyProfile TRANS_PROF_ACCESS sipHeader Alert-Info
set profiles services transparencyProfile TRANS_PROF_ACCESS sipHeader Error-Info
set profiles services transparencyProfile TRANS_PROF_ACCESS sipHeader User-Agent
set profiles services transparencyProfile TRANS_PROF_ACCESS sipHeader Referred-By excludedMethods register,subscribe,info,publish,message,options,update,bye
set profiles services transparencyProfile TRANS_PROF_ACCESS sipHeader Request-URI
set profiles services transparencyProfile TRANS_PROF_ACCESS sipHeader Accept-Language
set profiles services transparencyProfile TRANS_PROF_ACCESS sipHeader Contact
set profiles services transparencyProfile TRANS_PROF_ACCESS sipHeader P-Called-Party-Id
commit
set profiles services transparencyProfile TRANS_PROF_ACCESS sipMessageBody application/pidf+xml
set profiles services transparencyProfile TRANS_PROF_ACCESS sipMessageBody application/rlmi+xml
set profiles services transparencyProfile TRANS_PROF_ACCESS sipMessageBody message/external-body
set profiles services transparencyProfile TRANS_PROF_ACCESS sipMessageBody application/pidf+xml
set profiles services transparencyProfile TRANS_PROF_ACCESS sipMessageBody application/cpim-pidf+xml
set profiles services transparencyProfile TRANS_PROF_ACCESS sipMessageBody application/pidf-diff+xml
set profiles services transparencyProfile TRANS_PROF_ACCESS sipMessageBody application/dialog-info+xml
set profiles services transparencyProfile TRANS_PROF_ACCESS sipMessageBody application/simple-filter+xml
set profiles services transparencyProfile TRANS_PROF_ACCESS sipMessageBody application/resource-lists+xml
set profiles services transparencyProfile TRANS_PROF_ACCESS sipMessageBody application/conference-info+xml
set profiles services transparencyProfile TRANS_PROF_ACCESS sipMessageBody application/simple-message-summary
set profiles services transparencyProfile TRANS_PROF_ACCESS sipMessageBody application/vnd.3gpp.srvcc-ext ignoreTransparency yes
commit
set profiles services transparencyProfile TRANS_PROF_ACCESS  state enabled
commit
set addressContext ADDR_CONTEXT1 zone ZONE1 sipTrunkGroup TG_TOWARDS_UE services transparencyProfile TRANS_PROF_ACCESS
commit

Configuring Trunk Group Towards UE

set addressContext ADDR_CONTEXT1 ipInterfaceGroup LIG1 ipInterface LIF1 ceName SBX portName pkt0 ipAddress 10.4.8.16 prefix 24 altIpAddress fd00:10:6b50:248f::a altPrefix 60
set addressContext ADDR_CONTEXT1 ipInterfaceGroup LIG1 ipInterface LIF1 mode inService state enabled
set addressContext ADDR_CONTEXT1 ipInterfaceGroup LIG2 ipInterface LIF2 ceName SBX portName pkt2 ipAddress 10.4.9.16 prefix 24 altIpAddress fd00:10:6b50:249f::a altPrefix 60
set addressContext ADDR_CONTEXT1 ipInterfaceGroup LIG2 ipInterface LIF2 mode inService state enabled
set addressContext ADDR_CONTEXT1 ipInterfaceGroup LIG3 ipInterface LIF3 ceName SBX portName pkt0 ipAddress 10.4.8.18 prefix 24 altIpAddress fd00:10:6b50:248f::c altPrefix 60
set addressContext ADDR_CONTEXT1 ipInterfaceGroup LIG3 ipInterface LIF3 mode inService state enabled
set addressContext ADDR_CONTEXT1 ipInterfaceGroup LIG4 ipInterface LIF4 ceName SBX portName pkt0 ipAddress 10.4.8.18 prefix 24 altIpAddress fd00:10:6b50:248f::c altPrefix 60
set addressContext ADDR_CONTEXT1 ipInterfaceGroup LIG4 ipInterface LIF4 mode inService state enabled
set addressContext ADDR_CONTEXT1 staticRoute 10.0.0.0 8 10.4.8.1 LIG1 LIF1 preference 100

Global Configuration

Create Emergency Profile

set profiles services emergencyCallProfile IMS-EMG prefix 911
commit

Create SIP Security Profile

set profiles services sipSecurityProfile PCSCF sipSecurityMechanism ipsec-3gpp precedence 1
commit

Configure Ingress Trunk Group

set addressContext ADDR_CONTEXT1 zone ZONE1 sipTrunkGroup TG_PCSCF_INT_IP policy signaling ipSignalingProfile DFL_PCSCF_UE_TG_PROF
commit
set addressContext ADDR_CONTEXT1 zone ZONE1 sipTrunkGroup TG_PCSCF_INT_IP signaling P-HeaderExtensions insertpVisitedNetworkID 'exampleNetworks'
commit
set addressContext ADDR_CONTEXT1 zone ZONE1 sipTrunkGroup TG_PCSCF_INT_IP signaling registration requireRegistration required-nonpriority
commit
set addressContext ADDR_CONTEXT1 zone ZONE1 sipTrunkGroup TG_PCSCF_INT_IP signaling prefRequireTransparency enabled
commit
set addressContext ADDR_CONTEXT1 zone ZONE1 sipTrunkGroup TG_PCSCF_INT_IP signaling condIncMethInAllowHdr enabled
commit

Configure Outbound Direction

set addressContext ADDR_CONTEXT1 zone ZONE1 sipTrunkGroup TG_PCSCF_INT_IP signaling keepSupport enabled outboundSupport enabled
commit
set addressContext ADDR_CONTEXT1 zone ZONE1 sipTrunkGroup TG_PCSCF_INT_IP services natTraversal outboundTcpKeepaliveTimer 240 outboundUdpKeepaliveTimer 60
commit 

Configure Rx Interface

set addressContext ADDR_CONTEXT1 diamNode DIAMNODE originRealm sbc.com primaryOriginHost primary.sbc.com secondaryOriginHost secondary.sbc.com transactionTimeout 6000 ipInterfaceGroupName LIF1 ipV4Address 172.16.13.120
set addressContext ADDR_CONTEXT1 diamNode DIAMNODE state enabled
commit
set addressContext ADDR_CONTEXT1 diamNode DIAMNODE peer RX.EXAMPLE.COM fqdn htpcgw01.ims.mnc094.mcc235.3gppnetwork.org ipAddress 172.16.13.30
commit
set addressContext ADDR_CONTEXT1 diamNode DIAMNODE peer RX.EXAMPLE.COM state enabled
commit
set addressContext ADDR_CONTEXT1 diamNode DIAMNODE realmRoute RX.EXAMPLE.COM realm ims.mnc094.mcc235.3gppnetwork.org peer RX.EXAMPLE.COM appId rx
commit
set addressContext ADDR_CONTEXT1 diamNode DIAMNODE realmRoute RX.EXAMPLE.COM state enabled
commit
set addressContext ADDR_CONTEXT1 zone ZONE1 sipTrunkGroup TG_PCSCF_INT_IP media pcrf pcrfRealm ims.mnc094.mcc235.3gppnetwork.org pcrfCommitment supported cushionPacketSize enabled cushionNullSdp enabled 

Configure Rf Interface

set addressContext ADDR_CONTEXT1 diamNode DIAMNODE originRealm sbc.com primaryOriginHost example.sbc.com secondaryOriginHost example.sbc2.com transactionTimeout 6000 ipInterfaceGroupName LIF1 ipV4Address 172.16.13.120
set addressContext ADDR_CONTEXT1 diamNode DIAMNODE state enabled
commit
set addressContext ADDR_CONTEXT1 diamNode DIAMNODE peer RF.EXAMPLE.COM fqdn htpcgw01.ims.mnc094.mcc235.3gppnetwork.org ipAddress 172.16.13.30
commit
set addressContext ADDR_CONTEXT1 diamNode DIAMNODE peer RF.EXAMPLE.COM state enabled
commit
set addressContext ADDR_CONTEXT1 diamNode DIAMNODE realmRoute RF.EXAMPLE.COM realm ims.mnc094.mcc235.3gppnetwork.org peer RF.EXAMPLE.COM appId rf
commit
set addressContext ADDR_CONTEXT1 diamNode DIAMNODE realmRoute RF.EXAMPLE.COM state enabled
commit
set global signaling diamSigControls defaultCCF 172.16.13.30
commit
set global signaling diamSigControls enableRfApp enabled
commit
set global signaling diamSigControls generateFailedEventAcr enabled
commit
set global signaling diamSigControls maxACRretransmission 3 

Attach Emergency Profile

set addressContext ADDR_CONTEXT1 zone ZONE1 sipTrunkGroup TG_PCSCF_INT_IP services emergencyCallHandlingMode none emergencyCallProfile IMS-EMG
commit
set addressContext ADDR_CONTEXT1 zone ZONE1 sipTrunkGroup TG_PCSCF_INT_IP signaling usePsxRouteForEmergencyCall enable
commit 

Associate SIP Security Profile

set addressContext ADDR_CONTEXT1 zone ZONE1 sipTrunkGroup TG_PCSCF_INT_IP services sipSecurityProfile PCSCF
commit 

Zone 1 Configuration (Towards UE)

set addressContext ADDR_CONTEXT1 zone ZONE1 id 5 sipSigPort 1 ipInterfaceGroupName LIG1 ipAddressV4 10.4.8.16 ipAddressV6 fd00:10:6b50:248f::a portNumber 5060 transportProtocolsAllowed sip-tcp,sip-udp,sip-tls-tcp,sip-sctp mode inService state enabled
set addressContext ADDR_CONTEXT1 zone ZONE1 dialogTransparency enabled
set addressContext ADDR_CONTEXT1 zone ZONE1 disableZoneLevelLoopDetection disabled

Configuring Zone Index Profile

The following flags must be configured:

  • Zone Index Profile
  • Description
  • Zone Index
    Figure 4: Configuring Zone Index Profile

Configuring IP Signaling Profile

The following parameters are configured :

Configuring Common IP Attributes

The following must be enabled in PSX under "IP SIGNALING PROFILE":

  • No Port Number 5060.
  • Reject REFER.
  • ReQuery PSX on REGISTER Refresh.
  • Disable Host Translation.
  • End to End BYE.
  • End to End re-INVITE.
  • End to End UPDATE.
  • End to End PRACK.
  • Minimize Relaying Of Media Chnages From Other Call Leg
  • Store P-Charging-Vector.
  • Validate Access Nw Info Header.
    Figure 5: Configuring Common IP Attributes

Configuring Relay Flags

The following "Relay Flags" must be enabled under "Ip Signaling profile":

  • Dialog Event Package
  • Info
  • Options
  • Select Reject the REFER request if no match is found from Refer To Header Relay option.
    Figure 6: Configuring Relay Flags

Configuring Egress IP Attributes

The following parameters are to enabled :

  • Select SIP Only from IP Protocol Type.
  • BCI Interwork Encountered (in BCI option).
  • Transparency (in Privacy option).
  • Merge Received Contacts with Existing Contacts (in Redirect option).
  • Select Include None from Include Charge Information (in SIP Headers and Parameters option).
  • Select None from SIP TO Header Mapping (in SIP Headers and Parameters option).
  • Include OLIP (in SIP Headers And Parameters > Flags option).
  • Transparency For Destination Trunk Group Parameter (in SIP Headers And Parameters > Flags option).
  • End To End Ack (in SIP Headers And Parameters > Flags option).
  • Diversion (in SIP Headers And Parameters > Call Forwarding option).
    Figure 7: Configuring Egress IP Attributes

Configuring Ingress IP Attributes

The following parameter is to be enabled:

  • 181 Supported (in Flags option)
    Figure 8: Configuring Ingress IP Attributes

Configuring SIP Trunk Group

set addressContext ADDRESS_CONTEXT1 zone ZONE1 sipTrunkGroup TG_TOWARDS_UE
commit 

The following profiles/fields must be enabled:

  • Zone Index Profile
  • IP Signaling Profile
  • Feature Control Profile
  • Signaling Profile
  • SIP Domain
  • IP Version Preference
  • Use IPTG Routing (Hop By Hop Routing) For Ingress (Ingress > Flags)
  • Do Not Use For Fallback Bearer Capability (Egress > Flags)
  • IP Peer Supported (Egress > IPTG)
  • Egress IP Signaling Profile (Egress > IPTG)
  • Select Traffic Management Options from Trunk Group Reserved Level 1 and Trunk Group Reserved Level 2.
  • Select Services as Not Screened.
    Figure 9: Configuring SIP Trunk Group

Configuring SBC Towards S-CSCF

The following profiles are configured:

Configuring Transparency Profile

set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader To
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader From
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader Path
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader Accept
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader Reason
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader Server
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader Warning
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader Call-Info
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader Alert-Info
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader Error-Info
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader User-Agent
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader Referred-By excludedMethods register,subscribe,info,publish,message,options,update,bye
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader Request-URI
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader Accept-Language
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader P-Called-Party-Id
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader Require
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader Proxy-Require
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader Security-Client
set profiles services transparencyProfile TRANS_PROF_CORENW sipHeader Security-Verify
commit
set profiles services transparencyProfile TRANS_PROF_CORENW sipMessageBody application/pidf+xml excludedMethods register,invite,subscribe,info,publish,message,options,update,bye
set profiles services transparencyProfile TRANS_PROF_CORENW sipMessageBody application/pidf+xml
set profiles services transparencyProfile TRANS_PROF_CORENW sipMessageBody application/rlmi+xml
set profiles services transparencyProfile TRANS_PROF_CORENW sipMessageBody message/external-body
set profiles services transparencyProfile TRANS_PROF_CORENW sipMessageBody application/pidf+xml
set profiles services transparencyProfile TRANS_PROF_CORENW sipMessageBody application/cpim-pidf+xml
set profiles services transparencyProfile TRANS_PROF_CORENW sipMessageBody application/pidf-diff+xml
set profiles services transparencyProfile TRANS_PROF_CORENW sipMessageBody application/dialog-info+xml
set profiles services transparencyProfile TRANS_PROF_CORENW sipMessageBody application/simple-filter+xml
set profiles services transparencyProfile TRANS_PROF_CORENW sipMessageBody application/resource-lists+xml
set profiles services transparencyProfile TRANS_PROF_CORENW sipMessageBody application/conference-info+xml
set profiles services transparencyProfile TRANS_PROF_CORENW sipMessageBody application/simple-message-summary
commit
set profiles services transparencyProfile TRANS_PROF_CORENW state enabled
commit
set addressContext ADDR_CONTEXT1 zone ZONE2 sipTrunkGroup TG_TOWARDS_SCSCF services transparencyProfile TRANS_PROF_CORENW
commit

Configuring Zone Index Profile

set addressContext ADDR_CONTEXT1 zone ZONE2 dialogTransparency enabled
set addressContext ADDR_CONTEXT1 zone ZONE2 disableZoneLevelLoopDetection disabled

The following flags must be configured:

  • Zone Index Profile
  • Description
  • Zone Index
    Figure 10: Zone Index Profile for SCCAS

Configuring IP Signaling Profile

The following parameters must be configured under "Ip Signaling Profile".

Configuring Common IP Attributes

The following must be enabled in PSX under "IP SIGNALING PROFILE":

  • Add P-Charging Function Addr
  • Create P-Charging-Vector
  • Create P-Visited-Network Id
  • Customized Session Timer Behavior
  • Disable Host Translation
  • End To End BYE
  • End To End re-INVITE
  • End To End UPDATE
  • End To End PRACK
  • Enable Default PUI Procedures
  • Enable Dial String Handling
  • No Port Number 5060
  • P-Called-Party0Id-Support
  • Restrict History Info Header
  • Store P-Charging Vector
  • Store Service-Route Header
  • Validate Access Nw Info Header
    Figure 11: Common IP Attributes for SCCAS

Configuring Relay Flags

The following "Relay Flags" must be enabled under "Ip Signaling profile":

  • Dialog Event Package
  • Info
  • Options
  • Reg Event Package
  • Select Reject the REFER request if no match is found from Refer to Header Relay option.
    Figure 12: Relay Flags for SCCAS

Configuring Egress IP Attributes

The following parameters are to enabled :

  • Select SIP Only from IP Protocol Type
  • Select Transit PAI From Unregistered Peer from Flags
  • Select Use IP Signaling Peer Domain In R-URI (in Domain Name)
  • Select Include npdi from NPDI Options (in Number Portability Attributes option)
  • Select P-Preferred-ID from Privacy Information options (in Privacy option)

  • Select Include Privacy (in Privacy)
  • Select Merge Received Contacts with Existing Contacts from Contact Handling(under Redirect)
  • Select Include None from Include Charge Information (in SIP Headers and Parameters option)
  • Select Not Send from Session-Expires Refresher (in SIP Headers and Parameters option)
  • Select None from SIP TO Header Mapping (under SIP Headers And Parameters option)

  • Select Transparency For Destination Trunk Group Parameter(under Flags option)
  • Select End to End Ack (under Flags option)
  • Select Diversion from Redirect Information (under Call Forwarding)
    Figure 13: Egress IP Attributes for SCCAS

Configuring SIP Trunk Group

The following profiles/fields must be enabled:

  • Feature Control Profile
  • IP Signaling Profile
  • Signaling Profile
  • SIP Domain
  • Zone Index Profile
  • IP Version Preference
  • Use IPTG Routing (Hop By Hop Routing) For Ingress (Ingress > Flags)
  • Do Not Use For Fallback Bearer Capability (Egress > Flags)
  • IP Peer Supported (Egress > IPTG)
  • Egress IP Signaling Profile (Egress > IPTG)
  • Select Traffic Management Options from Trunk Group Reserved Level 1 and Trunk Group Reserved Level 2.
  • Select Services as Not Screened.
    Figure 14: SIP Trunk Group for SCCAS


Configuring I-CSCF

Refer Configuring SBC Towards S-CSCF/SCCAS section in Configuring SBC as IBCF.

Configuring IBCF

Configuring External Peer

set addressContext ADDR_CONTEXT1 zone ZONE3 id 5 sipSigPort 1 ipInterfaceGroupName LIG3 ipAddressV4 10.4.8.18 ipAddressV6 fd00:10:6b50:248f::c portNumber 5060 transportProtocolsAllowed sip-tcp,sip-udp,sip-tls-tcp,sip-sctp mode inService state enabled
set addressContext ADDR_CONTEXT1 zone ZONE3 dialogTransparency enabled


Refer IPTG-5 (Towards Peer IBCF) section in Configuring SBC as IBCF.

set addressContext ADDR_CONTEXT1 zone ZONE3 sipTrunkGroup IPTG-4 media mediaIpInterfaceGroupName LIG3
set addressContext ADDR_CONTEXT1 zone ZONE3 sipTrunkGroup IPTG-4 ingressIpPrefix 10.54.80.101 32
set addressContext ADDR_CONTEXT1 zone ZONE3 sipTrunkGroup IPTG-4 ingressIpPrefix 10.54.80.8 32
set addressContext ADDR_CONTEXT1 zone ZONE3 sipTrunkGroup IPTG-4 mode inService state enabled
set addressContext ADDR_CONTEXT1 zone ZONE3 sipTrunkGroup IPTG-4 signaling registration requireRegistration none
set addressContext ADDR_CONTEXT1 zone ZONE3 sipTrunkGroup IPTG-4 signaling relayNonInviteRequest enabled
set addressContext ADDR_CONTEXT1 zone ZONE3 sipTrunkGroup IPTG-4 services transparencyProfile IBCF_COMMON_HTP
set addressContext ADDR_CONTEXT1 zone ZONE3 sipTrunkGroup IPTG-4 callRouting sendRouteUriToPsx enabled
set addressContext ADDR_CONTEXT1 zone ZONE3 sipTrunkGroup IPTG-4 signaling skipDTGLookupForRouteHdr enabled
set addressContext ADDR_CONTEXT1 zone ZONE3 sipTrunkGroup IPTG-4 callRouting useRouteSet received
set addressContext ADDR_CONTEXT1 zone ZONE3 sipTrunkGroup IPTG-4 media omrAllowed enabled
set addressContext ADDR_CONTEXT1 zone ZONE3 sipTrunkGroup IPTG-4 media primaryRealmName RealmName2
set addressContext ADDR_CONTEXT1 zone ZONE3 sipTrunkGroup IPTG-4 media directMediaAllowed disabled
set addressContext ADDR_CONTEXT1 zone ZONE3 sipTrunkGroup IPTG-4 transitIoi "IBCF"
set addressContext ADDR_CONTEXT1 zone ZONE3 sipTrunkGroup IPTG-4 callRouting sendRouteUriToPsx enabled
set addressContext ADDR_CONTEXT1 zone ZONE3 sipTrunkGroup IPTG-4 services honorSdpClockRate enabled
set addressContext ADDR_CONTEXT1 zone ZONE3 sipTrunkGroup IPTG-4 services preconditions transparent

For PSX related configuration, refer to the following sections of IBCF Configuration (Zone 1 Configuration (Towards P-CSCF in Roaming)):

  • Configuring PSX Route URI Based Routing
  • Configuring IP Signaling Profile
  • Configuring SIP Trunk Group