The SBC re-initiates the precondition procedure whenever the ingress side Session Description Protocol (SDP) changes due to an 18x/200 OK or UPDATE received from the egress side. The SBC uses this UPDATE message before sending 200 OK to INVITE towards ingress instead of using the RE-INVITE message.

 Enable the preferUPDATEOverReINVITE parameter to use UPDATE instead of Re-INVITE on the ingress to communicate SDP when the call transitions to the confirmed state.

Command Syntax

% set addressContext default zone <zone_name> sipTrunkGroup <siptrunkgroup_name> signaling preferUPDATEOverReINVITE <enabled | disabled>

Command Parameters

preferUPDATEOverReINVITE Parameters

ParameterDescription
preferUPDATEOverReINVITE

Enable this flag on the ingress trunk group to allow the SBC to use UPDATE instead of Re-INVITE to communicate SDP towards ingress when the call is in the confirmed state.

The options include:

  • disabled
  • enabled

Note: This flag is not applicable when either the dialog transparency flag or the updatedAnswerIn200Ok flag is enabled on the SBC.  

Command Example

% set addressContext default zone ZONE_INGRESS sipTrunkGroup TG_INGRESS signaling preferUPDATEOverReINVITE enabled