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Overview

The E-CSCF functionality can be used when SBC acts as Proxy Call Session Control Function (P-CSCF). Therefore, the SBC acts as a combined P-CSCF and E-CSCF (P+E-CSCF).

The SBC as (P+E-CSCF) receives an emergency session establishment request from user equipment (UE) or a Serving Call Session Control Function (S-CSCF) and applies the following functionality as E-CSCF in addition to the normal P-CSCF functionality.

• SBC as E-CSCF forwards the session establishment request to the Emergency Access Transfer Function (EATF) in the serving IMS network for anchoring to support Single Radio Voice Call Continuity (SRVCC).
• SBC as E-CSCF requests Location Retrieval Function (LRF) to retrieve location information and proper routing information/PSAP destination, based on the configuration,
• SBC as E-CSCF routes the call to the destination Public Safety Answering Point (PSAP) returned by LRF and sends the location information and correlation information (ESQK in PAI header) to PSAP.
• SBC as E-CSCF sends the call to PSAP based on the routing information returned by LRF and PSX configuration by using any of the following:
  • Directly
  • Through Interconnection Border Control Functions (IBCF) to the IP-PSAP
  • Through Breakout Gateway Control Function (BGCF) to the PSTN PSAP

The ATCF is generally co-located with an existing functional element in the IMS architecture, such as the P-CSCF, IBCF, or MSC server. The most likely option for ATCF co-location is the P-CSCF as it is already in the path of all UE signaling with IMS. The IBCF is only in the path for a session when the UE is roaming, and the MSC server is only involved in a session during and after SRVCC. Thus, the IBCF and MSC server are not co-located with the ATCF. The E-CSCF may reside within the P-CSCF to support IMS Emergency procedures.

In the case of ATCF and E-CSCF integrated with P-CSCF, IMS-AGW acts as ATGW (as the SBC5xx0 acts as an integrated P-CSCF and IMS-AGW,

the ATCF/ATGW solution is also integrated in same box that is, the ATGW interface is not exposed externally).

The E-CSCF is responsible for routing emergency call requests to the nearest PSAP based on the callers location information, as well as other information, such as the type of emergency service being requested.  E-CSCF receives from the P-CSCF request for emergency session establishment, and if required, contacts the LRF to validate the location information given by the UE and routes the request to the appropriate destination.

At a high level, the functions performed by the ATCF are:

• Allocates a STN-SR.
• Includes itself for the SIP sessions.
• Instructs the ATGW to anchor the media path for originating and terminating sessions.
• Keeps track of sessions (either in pre-alerting state, alerting state, active or held) to perform Access Transfer of the selected session.
• Performs the Access Transfer and updates the ATGW with the new media path for the (CS) access leg, without requiring to update the remote leg.
• After Access Transfer, updates the SCC AS for which Access Transfer takes place. This ensures that the T-ADS have the information on the currently used access.
• Handles failure cases during the Access Transfer.

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

• Receives an emergency session establishment request from a P CSCF or an S-CSCF.
• If location information is not included in the emergency request or additional location information is required, the E CSCF requests the LRF to retrieve location information.
• If required, the E-CSCF requests the LRF to validate the location information included by the UE.
• Determines or queries the LRF for the proper routing information/PSAP destination.
• Route emergency session establishment requests to an appropriate destination including anonymous session establishment requests.
• Subject to local regulation, the E-CSCF may send the contents of the P-asserted ID or UE identification to the LRF.
• Based on operator policy, the E-CSCF may route the emergency IMS call to ECS for further call process.
• For supporting SRVCC, the E-CSCF forwards the session establishment request to the EATF in the serving IMS network for anchoring.

Deployment Scenario

The SBC acting as an E-CSCF can interact with

a third-party LRF. An LRF is responsible for retrieving the location information of the UE that has initiated an IMS emergency session. An LRF can interact with a location service

to manage ESQK allocation

. The ESQK is used by the PSAP to query the LRF for location information and optionally a callback number. Information provided by the LRF to the E‑CSCF includes the routing information to the appropriate PSAP and other parameters necessary for emergency services, which is forwarded to the PSAP by SBC as E-CSCF.

Some regions,

such as North America, may require the ability to provide the PSAP with an accurate initial

and

updated location estimate for the UE

. In such cases, the LRF

stores a record of the emergency session including all information provided by the E‑CSCF

, and releases the record when informed by the E‑CSCF that the emergency session has terminated. The information provided by the LRF to the E‑CSCF (for example, ESQK) then includes correlation information identifying both the LRF and the emergency session record in the LRF. This correlation information is transferred to the PSAP by the SBC as E-CSCF during session establishment. The PSAP

can use this information to request an initial location estimate from the LRF and/or to request an updated location estimate.

Call Flows

Global Configuration

set addressContext default zone ZONE_ACCESSNW disableZoneLevelLoopDetection disable 

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Attaching ATCF Profile to IPSP Attaching ATCF Profile to IPSP

Attaching ATCF Profile to IPSP

1. Select ATCF profile from the Access Transfer Policy Type option.

   Caption
   0 Figure 1 Selecting ATCF Profile
   Image Modified

2. Attach the ATCF profile to the IP SIGNALING PROFILE of a Trunk Group.

   Caption
   0 Figure 1 Attaching ATCF profile to the IPSP Trunk group
   Image Modified

Configuring SBC Towards UE

The following profiles are configured:

• Configuring Transparency Profile
• Configuring Zone Index Profile
  
• Configuring IP Signaling Profile
• Configuring SIP Trunk Group

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ConfiguringTransparencyProfile ConfiguringTransparencyProfile

Configuring Transparency Profile

set addressContext default zone ZONE_ACCESSNW sipTrunkGroup TG_TOWARDS_UE services transparencyProfile TRANS_PROF_ACCESS
commit

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ConfiguringZoneIndexProfile ConfiguringZoneIndexProfile

Configuring Zone Index Profile

The following flags must be configured:

• Zone Index Profile
• Description
• Zone Index

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ConfiguringIPSignalingProfile ConfiguringIPSignalingProfile

Configuring IP Signaling Profile

The following parameters are configured :

• Configuring Common IP Attributes
• Configuring Relay Flags
• Configuring Egress IP Attributes
• Configuring Ingress IP Attributes

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ConfiguringCommonIPAttributes ConfiguringCommonIPAttributes

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 Changes From Other Call Leg
• Store P-Charging-Vector
• Validate Access Nw Info Header

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ConfiguringRelayFlags ConfiguringRelayFlags

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.

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ConfiguringEgressIPAttributes ConfiguringEgressIPAttributes

Configuring Egress IP Attributes

The following parameters must be 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).

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Configuring Ingress IP Attributes Configuring Ingress IP Attributes

Configuring Ingress IP Attributes

The following parameter is to be enabled:

• 181 Supported (in Flags option)

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ConfiguringSIPTrunkGroup ConfiguringSIPTrunkGroup

Configuring SIP Trunk Group

set addressContext "default" zone "ZONE_ACCESSNW" 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

Configuring SBC Towards MSC

The following profiles are configured:

• Configuring Transparency Profile
• Configuring Zone Index Profile
• Configuring IP Signaling Profile
• Configuring SIP Trunk Group

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ConfiguringTransparencyProfileMSC ConfiguringTransparencyProfileMSC

Configuring Transparency Profile

set addressContext default zone ZONE_CORENW sipTrunkGroup TG_TOWARDS_IMSCORE services transparencyProfile TRANS_PROF_MSC
commit

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ConfiguringZoneIndexProfileMSC ConfiguringZoneIndexProfileMSC

Configuring Zone Index Profile

set addressContext "default" zone "ZONE_CORENW" sipTrunkGroup "TG_TOWARDS_MSC"

The following flags must be configured:

• Zone Index Profile
• Description
• Zone Index

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ConfiguringIPSignalingProfileMSC ConfiguringIPSignalingProfileMSC

Configuring IP Signaling Profile

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

• Configuring Common IP Attributes
• Configuring Relay Flags
• Configuring Egress IP Attributes
• Configuring Ingress IP Attributes

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ConfiguringCommonIPAttributesMSC ConfiguringCommonIPAttributesMSC

Configuring Common IP Attributes

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

• Add P-Charging Function Addr
• No Port Number 5060
• P-Called-Party-Id-Support
• Create P-Charging-Vector
• Create P-Visited-Network Id
• Create Path Header
• Disable Host Translation
• Restrict History Info Header
• 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
• Store P-Charging Vector
• Store Service -Route Header
• Validate Access Nw Info Header

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ConfiguringRelayFlagsMSC ConfiguringRelayFlagsMSC

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.
  

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ConfiguringEgressIPAttributesMSC ConfiguringEgressIPAttributesMSC

Configuring Egress IP Attributes

The following parameters are to enabled :

• Select SIP Only from IP Protocol Type
• BCI Interwork Encountered (in BCI)
• Select Use IP Signaling Peer Domain In R-URI (in Domain Name)
• Select Include npdi from NPDI Options (in Number Portability Attributes option)
• Select Include Privacy and Do Not Include Tel URI in PAI Header(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 None from SIP TO Header Mapping (under SIP Headers And Parameters option)
• Select Include CPC Information(under Flags 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)

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ConfiguringIngressIPAttributesMSC ConfiguringIngressIPAttributesMSC

Configuring Ingress IP Attributes

The following parameter must be enabled:

• Map Called Party Category In P-Sig-Info Header

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ConfiguringSIPTrunkGroupMSC ConfiguringSIPTrunkGroupMSC

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.

Configuring SBC Towards SCCAS or IMS Core

The following profiles are configured:

• Configuring Transparency Profile
• Configuring Zone Index Profile
• Configuring IP Signaling Profile
• Configuring SIP Trunk Group

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ConfiguringTransparencyProfileSCCAS ConfiguringTransparencyProfileSCCAS

Configuring Transparency Profile

set addressContext default zone ZONE_CORENW sipTrunkGroup TG_TOWARDS_IMSCORE services transparencyProfile TRANS_PROF_CORENW
commit

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ConfiguringZoneIndexProfileSCCAS ConfiguringZoneIndexProfileSCCAS

Configuring Zone Index Profile

set addressContext default zone ZONE_CORENW disableZoneLevelLoopDetection disabled

The following flags must be configured:

• Zone Index Profile
• Description
• Zone Index

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ConfiguringIPSignalingProfileSCCAS ConfiguringIPSignalingProfileSCCAS

Configuring IP Signaling Profile

The following parameters must be configured under IP SIGNALING PROFILE:

• Configuring Common IP Attributes
• Configuring Relay Flags
• Configuring Egress IP Attributes

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ConfiguringCommonIPAttributesSCCAS ConfiguringCommonIPAttributesSCCAS

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

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ConfiguringRelayFlagsSCCAS ConfiguringRelayFlagsSCCAS

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.
  

Anchor
ConfiguringEgressIPAttributesSCCAS ConfiguringEgressIPAttributesSCCAS

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)

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ConfiguringSIPTrunkGroupSCCAS ConfiguringSIPTrunkGroupSCCAS

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.

Configuring SBC Towards IBCF

The following profiles are configured:

• Configuring Transparency Profile
• Zone Configuration (Towards Peer in External)
• Configuring Zone Index Profile
• Configuring PSX Route URI Based Routing
  
• Configuring IP Signaling Profile
• Configuring SIP Trunk Group

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ConfiguringTransparencyProfileIBCF ConfiguringTransparencyProfileIBCF

Configuring Transparency Profile

set profile services transparencyProfile IBCF_COMMON_HTP sipHeader Accept-Language

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ZoneConfiguration(TowardsPeerinExternal) ZoneConfiguration(TowardsPeerinExternal)

Zone Configuration (Towards Peer in External)

 set addressContext default zone ZONE_CORENW dialogTransparency enabled

IBCF (Towards Peer IBCF/IPX)

Common Configuration

set addressContext default zone ZONE3 sipTrunkGroup IBCF transitIoi "IBCF"

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ConfiguringZoneIndexProfileIBCF ConfiguringZoneIndexProfileIBCF

Configuring Zone Index Profile

The following flags must be configured:

• Zone Index Profile
• Description
• Zone Index

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ConfiguringPSXRouteURIBasedRouting ConfiguringPSXRouteURIBasedRouting

Configuring PSX Route URI Based Routing

The following flags must be configured:

1. Create a Feature Profile.

   1. Enable Perform Route Header Based Routing.

      Caption
      0 Figure 1 Route Header Based Routing
      Image Modified

   2. On the SIP Trunk Group , select the mapped Feature Control Profile and IP Signaling Profile.

      Caption
      0 Figure 1 Ingress SIP TG
      Image Modified

2. Create Call Parameter Filter Profile and set the values for :
   
   1. Type as "Regex Group". 
   2. Variable Type as "Route URI Host Part".
   3. Configure RouteURI as matching Regex String. 
      

   Caption
   0 Figure 1 Call Parameter Filter Profile
   Image Modified

   
   

3. Create Policy Profile.
   
   1. Enable URI and URI Action as "Override IP Peer with Route URI Host Part".
   2. Map the created Call Parameter Filter Profile.

   Caption
   0 Figure 1 Policy Profile
   Image Modified

   
   

4. Map the Policy Profile under Policy Profile Group.

   Caption
   0 Figure 1 Policy Profile Group
   Image Modified

   
   

5. On the SIP Trunk Group under Egress, select the Output Policy Profile Group.

   Caption
   0 Figure 1 Egress SIP Trunk Group
   Image Modified

   
   

6. For domain based configuration, select UserName Routing.

   1. Select the already mapped Call Parameter Filter Profile and Domain Name from the drop-down.

   Caption
   0 Figure 1 Username Routing

1. Image Added

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ConfiguringIPSignalingProfileIBCF ConfiguringIPSignalingProfileIBCF

Configuring IP Signaling Profile

The following parameters must be configured under IP SIGNALING PROFILE:

• Configuring Common IP Attributes
• Configuring Relay Flags
• Configuring Egress IP Attributes

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ConfiguringCommonIPAttributesIBCF ConfiguringCommonIPAttributesIBCF

Configuring Common IP Attributes

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

• Add P-Charging-Function Addr
• Create P-Charging-Vector
• Create P-Visited-Network Id
• Create Path Header
• 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 Dial String Handling
• No Port Number 5060
• P-Called-Party-Id-Support
• Restrict History Info Header
• Store P-Charging Vector
• Store Service-Route Header
• Validate Access Nw Info Header

Anchor
ConfiguringRelayFlagsIBCF ConfiguringRelayFlagsIBCF

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.

Anchor
ConfiguringEgressIPAttributesIBCF ConfiguringEgressIPAttributesIBCF

Configuring Egress IP Attributes

The following Egress IP Attributes must be enabled:

• Select SIP Only from IP Protocol Type.
• Transit PAI From Unregistered Peer (under Flags)
• Use IP Signaling Peer Domain In R-URI (under Domain Name)
• Select Include npdi from NPDI Options (under Number Portability Attributes option).
• Select P-Preferred-ID from Privacy Information (under Privacy option).
• Include Privacy (under Privacy > Flags)
• Merge Received Contacts with Existing Contacts (under Redirect)
• Select Include None from Include Charge Information option (under SIP Headers and Parameters)
• Select Not Send from Session-Expires Refresher option (under SIP Headers and Parameters)
• Select None from SIP TO Header Mapping option (under SIP Headers and Parameters)
• Transparency For Destination Trunk Group Parameter (under SIP Headers and Parameters > Flags)
• End To End Ack (under SIP Headers and Parameters > Flags)
• Diversion (under SIP Headers and Parameters > Call Forwarding)
• Select Retry Without ETS from the Action For ETS 400 Responses With 417 Reason Code drop-down box (under SIP RPH ETS)
• Set ETS Default Priority Value as 0  (under SIP RPH ETS)

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ConfiguringSIPTrunkGroupIBCF ConfiguringSIPTrunkGroupIBCF

Configuring SIP Trunk Group

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)
• Select Traffic Management Options from Trunk Group Reserved Level 1 and Trunk Group Reserved Level 2.
• Select Services as Not Screened.

Configuring SBC Towards E-CSCF

The following profiles are configured:

• Configuring Transparency Profile
• Configuring Emergency Calls
  
• Configuring Zone Index Profile
• Configuring IP Signaling Profile
• Configuring SIP Trunk Group

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ConfiguringTransparencyProfileE-CSCF ConfiguringTransparencyProfileE-CSCF

Configuring Transparency Profile

set addressContext default zone ZONE_ECSCF sipTrunkGroup TG_TOWARDS_ECSCF services transparencyProfile TRANS_PROF_ECSCF
commit

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ConfiguringEmergencyCallsE-CSCF ConfiguringEmergencyCallsE-CSCF

Configuring Emergency Calls

set profiles services emergencyCallProfile EMG-ECSCF sosInContactOfRegister enable
comm 

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ConfiguringZoneIndexProfileE-CSCF ConfiguringZoneIndexProfileE-CSCF

Configuring Zone Index Profile

The following fields must be configured:

• Zone Index Profile
• Description
• Zone Index

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ConfiguringIPSignalingProfileE-CSCF ConfiguringIPSignalingProfileE-CSCF

Configuring IP Signaling Profile

The following parameters must be configured under IP SIGNALING PROFILE:

• Configuring Common IP Attributes
• Configuring Relay Flags
• Configuring Transparency Flags
• Configuring Egress IP Attributes
• Configuring Ingress IP Attributes

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ConfiguringCommonIPAttributesE-CSCF ConfiguringCommonIPAttributesE-CSCF

Configuring Common IP Attributes

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

• Disable Host Translation
• End to End BYE
• End to End RE-INVITE
• End to End UPDATE
• End to End PRACK
• Insert Peer Address As Top Route Header
• No Port Number 5060
• ReQuery PSX on REGISTER Refresh
• Store P-Charging-Vector
• Validate Access Nw Info Header

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ConfiguringRelayFlagsE-CSCF ConfiguringRelayFlagsE-CSCF

Configuring Relay Flags

The following Relay Flags must be enabled under IP SIGNALING PROFILE:

• Conference Event Package
• Dialog Event Package
• Info
• Message
• Options
• PUBLISH
• REFER
• Reg Event Package
• Status Code 4XX-6XX
• Select Reject the REFER request if no match is found from Refer To Header Relay option.

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ConfiguringTransparencyFlagsE-CSCF ConfiguringTransparencyFlagsE-CSCF

Configuring Transparency Flags

The following Transparency Flag must be enabled under IP SIGNALING PROFILE:

• Request-URI

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ConfiguringEgressIPAttributesE-CSCF ConfiguringEgressIPAttributesE-CSCF

Configuring Egress IP Attributes

The following Egress IP Attributes must be enabled:

• Select SIP Only from IP Protocol Type.
• Disable 2806 Compliance (under Flags)
• Transit PAI From Unregistered Peer (under Flags)
• Add Loop Back Route Header (under Flags)
• Select Include npdi from NPDI Options (under Number Portability Attributes option).
• Select P-Preferred-ID from Privacy Information (under Privacy option).
• Merge Received Contacts with Existing Contacts (under Redirect)
• Select Include None from Include Charge Information option (under SIP Headers and Parameters)
• Select Original Called Number (OCN) from SIP TO Header Mapping option (under SIP Headers and Parameters)
• Include CPC Information (under SIP Headers and Parameters > Flags)
• Transparency For Destination Trunk Group Parameter (under SIP Headers and Parameters > Flags)
• End To End Ack (under SIP Headers and Parameters > Flags)
• Diversion (under SIP Headers and Parameters > Call Forwarding)
• Select Retry Without ETS from the Action For ETS 400 Responses With 417 Reason Code drop-down box (under SIP RPH ETS)
• Set ETS Default Priority Value as 0  (under SIP RPH ETS)

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ConfiguringIngressIPAttributesE-CSCF ConfiguringIngressIPAttributesE-CSCF

Configuring Ingress IP Attributes

The following Ingress IP Attributes must be enabled:

• 181 Supported (under Flags option)

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ConfiguringSIPTrunkGroupE-CSCF ConfiguringSIPTrunkGroupE-CSCF

Configuring SIP Trunk Group

set addressContext default zone ZONE_ECSCF sipTrunkGroup TG_TOWARDS_ECSCF services emergencyCallProfile EMG-ECSCF
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.