NAT Modes

The specific addresses used in translating URIs in the SIP message depend on whether the Oracle® Enterprise Session Border Controller is performing NAT functions for a trusted or untrusted network. This condition is determined by the NAT mode value you enter when you configure the SIP config element. The NAT modes are:

• untrusted—The SIP proxy is associated with an address for an untrusted network (the address value you entered when you configured the SIP interface’s SIP port parameter), and the home address in the SIP NAT is the address of the external realm/network. When the URI contains the external address, it is translated to the SIP NAT’s home proxy address (or to the SIP port address if the home proxy address field is empty). When a URI contains the external proxy address, it is translated to the home address.

  If the URI contains any other private address (matching the realm’s address prefix, identified in the SIP NAT’s realm ID), it is encrypted and the address is replaced with the home address value. If the URI contains a user part, a suffix consisting of the user NAT tag and the encrypted address is appended to the user part. For example, with a user NAT tag value of -private-, the private URI of sip@123192.169.200.17:5060 will become the public URI of sip:123-private-eolmhet2chbl3@172.16.0.15.

  If there is no user part, the host consists of the host NAT tag followed by the encrypted address and the domain suffix. A maddr parameter equal to the home address (or received in the case of a Via header) is added to the URI. For example, with a host NAT tag value of PRIVATE- and a domain suffix value of private.com, the private URI of sip:192.168.200.17:5060 will become the public URI of sip:PRIVATE-eolmhet2chbl3.private.com:5060;maddr=172.16.0.15.

• trusted—The SIP proxy is on a trusted network (the address value you entered when you configured the SIP interface’s SIP port parameter), and the SIP NAT’s external address is the public address of the external realm/network. When the URI contains the home address value, it is translated to the value set for the external proxy address. When the URI contains the SIP proxy’s address, it is translated to the external address. If the URI contains any other private address (matching the realm’s address prefix, identified in the SIP NAT’s realm ID), the private address is encrypted and the address is replaced with the external address.

  Note:

  Do not use the home proxy address value with private NAT functioning.