In this section:
The SBC supports optionally using random alphanumeric string for the useInfo of Contact header in Register messages, INVITE requests, 1xx and 2xx responses (except for '100 trying') of terminating INVITE messages generated by the SBC. To facilitate this, an optional control flag useRandomUserInfoInContactHdr
is added at the egress Trunk Group level (from message direction perspective). The default setting is 'disabled'. See command syntax below.
In support of this feature, the SBC generates a random number including a static prefix depending upon the type of request generated:
The userInfo part length can be up to 20 bytes. Because the Contact header length is limited to 64 bytes, use an SMM rule to remove "reg-info", "dtg", "q", Expires, and other parameters from Contact header of Register request. Add the Expires header in the request using expires parameter value if Expires header does not already exist. Apply the SMM profile as the "outputAdapterProfile" for the IP trunk group facing the Network/Registrar using the syntax.
% set addressContext <acName> zone <zoneName> sipTrunkGroup <tgName> signaling messageManipulation outputAdapterProfile <SMM profile name>
To use this feature, the following actions must be taken:
Configure the remoteDeviceType as "appServer" for the zone facing the Network/Registrar to specify call direction from Registrar/AppServer using CLI syntax:
% set addressContext <acName> zone <zoneName> remoteDeviceType appServer
Disable the transparency flags "passCompleteContactHeader" and "contactHeader" in the IP Signaling Profile facing the Registrar/network using CLI syntax:
% set profiles signaling ipSignalingProfile <profile_name> commonIpAttributes transparencyFlags passCompleteContactHeader disable % set profiles signaling ipSignalingProfile <profile_name> commonIpAttributes transparencyFlags contactHeader disable
The Transparency Profile is the recommended method of configuring transparency on the SBC Core for new deployments as well as when 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.
The SBC acting as P-CSCF supports Contact header full transparency under the following conditions:
SBC transparently passes Contact header when "gr" parameter is present in Contact header even when full Contact header transparency is not enabled.
SBC can be configured to pass Contact header when "isFocus" parameter is present in Contact header even when full Contact header transparency is not enabled.
To enable Contact header full transparency, enable the passCompleteContactHeader
flag in the IP Signaling Profiles associated with the core and peer SIP trunk groups.
Example:
% set profiles signaling ipSignalingProfile DFL_PCSCF_UE_TG_PROF commonIpAttributes transparencyFlags passCompleteContactHeader enable % commit % set profiles signaling ipSignalingProfile DFL_PCSCF_CORE_TG_PROF commonIpAttributes transparencyFlags passCompleteContactHeader enable % commit
Refer to Common IP Attributes - SIP - CLI for CLI command details.
The 3GPP specification 24.229 (release 12) requires the contact header to pass transparently when the contact header contains isFocus
parameter. In previous releases, the SBC used passCompleteContactHeader
flag to control "Contact" header transparency used to achieve this functionality. However, this parameter enables contact header transparency for all the requests.
contactTransparencyForIsFocusMediaTag
flag to allow contact header transparency for all requests and responses when isFocus
parameter is received in Contact header. When enabled, contact header is transparently sent in outgoing message if isFocus
parameter is received in contact header. This parameter is disabled by default. This flag is configurable from an external PSX.For SBC configuration details, refer to:
For PSX-related information, refer to the PSX documentation.