In this section:
The routing parameter, useRouteSet, is used in conjunction with the PSX in the context of performing its routing logic (i.e gathering the address of the called party for instance). In this way, routing information can be sent from the SBC to the PSX and Destination Trunk Group (DTG) using the route sent by the PSX for REGISTER request.
The SBC determines whether the PSX should perform pattern matching logic or not using "skipPatternMatching
" option of SIP trunk group's useRouteSet
parameter. If this indication is set, the PSX returns the destination routing information provided to it in the Routing AVP of the Policy request back to the SBC in the Policy response. For more information on Pattern Matching by the PSX, refer to PSX Documentation.
This feature also allows the SBC to eliminate all the extraneous routing decisions and always uses the information returned to it by the PSX in the policy response to determine the next immediate destination.
The below useRouteSet
options describes the various routing scenarios supported by the SBC.
This option is used along with the flag "sendRouteUriToPsx
" (see SIP Trunk Group - Call Routing - CLI for CLI details).
When you enable
sendRouteUriToPsx
flag, the Stored service Route or Path header is sent to the PSX.
The SBC sends Stored Service-Route or Path along with the DTG route information to the PSX .
The PSX sends back the route to the SBC with the exact route information.
When you disable
sendRouteUriToPsx
option, route-URI is not sent to the PSX.
Roaming or Stored – This option is used in P-CSCF for supporting the roaming as well as non-roaming scenarios. This option is used along with the "sendRouteUriToPsx
" flag.
The register URI routing information is sent to the PSX.
The SBC sends URI along with the DTG route information to the PSX.
The PSX sends back the route to SBC with the exact route information.
For Non-Roaming User
The register URI routing information is sent to the PSX.
The SBC sends route URI along with DTG route information.
Set SkipPatternMatch
flag to TRUE.
Rcb Next Hop And Stored – This option is used when the operator wants to ensure the messages from registered subscriber go to the same next immediate destination as the registration.
When using this option, ensure "sendRouteUriToPsx
" flag is enabled.
If you enable sendRouteUriToPsx
option, the register URI routing information (registrar IP along with the DTG route information) is sent to the PSX.
Received
This is a legacy option. This option is used for the IBCF functionality when stateless Registration Relay is in effect. This indicates that the routing information received in the route header portion of the incoming message. This routing information is used for determining the next immediate destination route.
This option is used along with the "sendRouteUriToPsx
" option to either enable/disable
. You need to also enable " skipDTGLookupForRouteHdr
" to use the received option.
When you enable
sendRouteUriToPsx
option, the top-most non-SBC Route-URI is sent to the PSX.
disable
sendRouteUriToPsx
option, route-URI is not sent to the PSX.The SBC as a P-CSCF marks a registered user as roaming based on the data provided by the PSX in the policy response of a REGISTER message, and also routes the Non-REGISTER message from roaming UE based on DTG provided by the PSX during REGISTRATION. Additional SBC routing functionality is described below.
useRouteSet
option "roamingOrStored
"].Send Domain Name in PATH Header of Outgoing REGISTER.
sendRouteUriToPsx
' flag on the ingress trunk group is enabled.Send Domain Name in PATH Header of Outgoing REGISTER.
useRouteSet
is set to roamingOrStored
and UE is Roaming User, the PSX route is honored.useRouteSet
is received and ROUTE-URI is passed to the PSX, the PSX route is honored.Below is a simplified call flow diagram depicting call origination and REGISTRATION of roaming UE.