This article describes the necessary steps to configure a SIP Outbound Proxy on the SBC Edge (SBC).

Overview

The Outbound Proxy feature sends all SIP outbound requests to an Outbound Proxy Server of choice regardless where the Request URI points to. Outbound Proxies are configured in the SIP Signaling Groups (SIP SG) and are valid for Signaling Groups who's SIP Mode is set to one of the following:

  • Basic Call
  • Forward Registration
  • Forward Registration After Local Processing

In the Basic Call mode, the outbound INVITE request is constructed using the Server table as the destination. If an Outbound Proxy is configured, the outbound INVITE is sent to the outbound proxy instead of the available server from the Server table.

In both Fwd Registration and Fwd Reg. After Local Processing modes, the outbound REGISTER request is constructed using the Registrar address as the destination. If Outbound Proxy is configured, the outbound REGISTER is sent to the outbound proxy instead of the Registrar address.

Important Notes
  • In Local Registrar mode, the Outbound Proxy configuration item is disabled and its value is not used.
  • If a SIP Server table which has Monitoring enabled, is associated with a SG having an Outbound Proxy configured, all the SIP OPTIONS requests generated by the SBC for monitoring purposes, are sent to the Outbound Proxy address configured on the SG.

Outbound Proxy Configuration or Basic Call mode

  1. In the WebUI, click the Settings tab.
  2. In the left navigation pane, go to SIP Server Tables
  3. Create a SIP Server Table (i.e., fes1.uxtestlab.com with the relevant port, protocol, profile, etc.

    Create SIP Server Table

  4. In the left navigation pane, go to Signaling Groups > (the SIP Signaling Group you plan to use for your deployment).
  5. Configure the SIP Signaling Group to use an Outbound Proxy.
    1. Select the SIP Server table you created above from the SIP Server Table list box.
    2. Enter the IP Address of FQDN of the Proxy Server in the Outbound Proxy text box.
    3. Enter the relevant port number in the Outbound Proxy Port text box.

      Configure SIP Signaling Group

Usage Example

Once an Outbound Proxy is configured on a SIP Signaling group, all SIP calls landing on that SIP SG are routed through a Proxy to the actual end points. This is typical in a SIP Trunking scenarios whereby the SBC offloads all the enterprise SIP traffic onto an ITSP (Internet Telephony Service Provider) SIP network which exposes a Proxy configured as an Outbound Proxy on the SBC.

In this example, entities are configured with following:

SBC

ITSP

Outbound Proxy

134.56.227.204

134.56.227.73

134.56.227.73

testux204.uxtestlab.com

fes1.uxtestlab.com

fes1.uxtestlab.com

Using the Log Exchange utility, you can verify the Outbound Proxy configuration in action —

Verify Outbound Proxy Configuration