Before You Configure

The Oracle® Enterprise Session Border Controller ’s IWF requires that there be complete configurations for both SIP and for H.323. These two sets of configurations function together when the interworking is configured and enabled.

You enable the Oracle® Enterprise Session Border Controller ’s interworking capability when you set the IWF configuration’s state parameter to enabled, and all required H.323 and SIP configurations are established. This means that all of the following configurations must be established:

A full SIP configuration, including SIP interfaces, SIP ports, SIP-NATs (if needed), and SIP features
A full H.323 configuration, including H.323 global and H.323 interface configurations
Local policy and local policy attributes (the IWF will not work without these configurations)
Media profiles
Session agents and, if needed, session agent groups

H.323 Configuration

You must have a complete configuration to support H.323 traffic on your Oracle® Enterprise Session Border Controller , including any required support for H.323 Fast Start or Slow Start.

In the H.323 interface configuration, you are able to configure interfaces that enable communication between H.323 devices (for audio, video, and/or data conferencing sessions).

If you know that your Oracle® Enterprise Session Border Controller will be handling traffic originating in Slow Start H.323, you must establish the appropriate list of media profiles in the IWF configuration. Handling Slow Start traffic also requires that you establish appropriate local policy (and local policy attribute) configurations, but configuring session agents and session agent groups is optional.

SIP Configuration

SIP functionality must also be configured on your Oracle® Enterprise Session Border Controller that will perform IWF translations. You must use appropriate local policy (and local policy attribute) configurations, but configuring session agents and session agent groups is optional. If you use session agents, then you must also configure the information you need for media profiles.

The Role of Local Policy

You must configure local policies (and local policy attributes, if necessary) in order for translations between SIP and H.323 to take place. These local policies determine what protocol is used on the egress side of a session. Local policy and local policy attribute configurations make routing decisions for the session that are based on the next hop parameter that you set. The next hop can be any of the following:

IPv4 address of a specific endpoint
Hostname or IPv4 address of a session agent
Name of a session agent group

You can use the application protocol parameter in the local policy attributes configuration as a way to signal the Oracle® Enterprise Session Border Controller to interwork the protocol of an ingress message into a different protocol as it makes its way to its egress destination (or next hop).

For example, if you set the application protocol parameter to SIP, then an inbound H.323 message will be interworked to SIP as it is sent to the next hop. An inbound SIP message would travel to the next hop unaffected. Likewise, if you set the application protocol parameter to H.323, then an incoming SIP message will be interworked to H.323 before the Oracle® Enterprise Session Border Controller forwards it to the next hop destination.

The following example shows a configured local policy and its attributes used for IWF traffic.

local-policy
        from-address
                                       *
        to-address
                                       444
        source-realm                   *
        state                          enabled
        last-modified-date             2004-04-20 17:43:13
        policy-attribute
                next-hop                       sag:sag_internal
                realm                          internal
                replace-uri                    disabled
                carrier
                start-time                     0000
                end-time                       2400
                days-of-week                   U-S
                cost                           0
                app-protocol                   SIP
                state                          enabled
                media-profiles

Local Policy in an IWF Session Initiated with H.323

In a session where the Oracle® Enterprise Session Border Controller is interworking H.323 to SIP, it internally forwards the session on for interworking when:

The next hop in the local policy is configured as a SIP session agent
The next hop in the local policy is configured as a SIP session agent group
The next hop in the local policy is not configured as a session agent or session agent group, and the application protocol parameter is set to SIP in the local policy attributes configuration.

Local Policy in an IWF Session Initiated with SIP

In a session where the Oracle® Enterprise Session Border Controller is interworking SIP to H.323, it internally forwards the session on for interworking when:

The next hop in the local policy is configured as an H.323 session agent
The next hop in the local policy is configured as an H.323 session agent group
The next hop in the local policy is not configured as a session agent or session agent group, and the application protocol parameter is set to H.323 in the local policy attributes configuration
In this case the local policy should also define the egress realm, which you can set in the realm parameter of the local policy attributes configuration.

H.323-SIP Source Call Address Passthrough

For FCC auditing requirements, the Oracle® Enterprise Session Border Controller (ESBC) can provide the originating IP address of endpoints using the Video Relay Service (VRS) service.

Because the FCC also requires h.323 for all calls between VRS vendors, the ESBC passes the IP address and port information in the h.225 sourceCallSignalAddress through the h.323 Inter-working Function (IWF) function. You can extract the information from a SIP header parameter in the SIP message. You can use any SIP header parameter.

The SIP INVITE message includes a new header type called h225SourceCallSignalAddress. For example:

INVITE sip:1000@192.168.38.2:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.38.0:5060;branch=z9hG4bK55gtsj3018lfr5etc7e1.1
Contact: "2000"<sip:2000@192.168.38.0:5060;transport=udp>
Supported: 100rel
From: "2000"<sip:2000@192.168.38.0:5060>;tag=5435c12f000e2e7b
To: <sip:1000@192.168.38.2:5060>
Call-ID: 00000100007f13ce5435c12f000ddcc4@127.0.0.1
h225SourceCallSignalAddress: 172.16.38.5:10005   <--New header type.
CSeq: 2 INVITE
Content-Length: 126
Content-Type: application/sdp
Max-Forwards: 70

v=0
o=IWF 1 1 IN IP4 192.168.38.0
s=H323 Call
c=IN IP4 192.168.38.0
t=0 0
m=audio 10000 RTP/AVP 0
a=rtpmap:0 PCMU/8000

You must enable and configure the h225SourceCallSignalAddress parameter on the ESBC to perform IWF operations. You can enable and configure this parameter from the ACLI command line or from the Web GUI in Advanced mode.