SIP Tel URI Support
The Oracle® Enterprise Session Border Controller maps H.323 addresses to either SIP URIs or Tel URIs. You can configure the Oracle® Enterprise Session Border Controller to include Tel URIs in the following SIP headers for calls that require the IWF:
- Request Line
- To
- From
When Tel URI support is not used on a Oracle® Enterprise Session Border Controller performing IWF translations, the SIP INVITE is formatted like it is in the following example. This example uses 192.168.5.5 as the external proxy address, or the next hop (as configured in the local policy).
INVITE sip:602@192.168.5.5:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.5.58:5060;branch=z9hG4bKIWF0aqoqg001g11a7kos4g0
Contact: <sip:603@192.168.5.58:5060>
From: <sip:603@192.168.5.58:5060>;tag=4069ac210018a0
To: <sip:602@192.168.5.5:5060>In the example above, the session needs to be routed to another SIP proxy that can resolve an E.164 number to a SIP address. However, the next SIP proxy must be informed that the message will be routed based on the included E.164 number; the SIP address of the Request URI does not have a routable SIP address. To devise a routable address, the Request URI must be reconstructed as a Tel URI.
Without Tel URI support configured, the terminating SIP user would be required to have an address of 602@192.168.5.5, where the IPv4 address portion is the same as the address for the proxy. If it were not the same, then the session would terminate at the proxy. However, the proxy would be unable to handle the session because the SIP address it received would be unknown/unroutable.
Because it is not desirable to have an IPv4 address be the user-identity and rely on the configuration of the IP network, the SIP INVITE generated by the Oracle® Enterprise Session Border Controller and sent to the proxy must have the following format if it is sent to an H.323 entity.
INVITE tel:2345 SIP/2.0
Via: SIP/2.0/UDP 192.168.5.52:5060;branch=z9hG4bKIWFaqoqq00cobgf9so10o0
Contact: <sip:1234@192.168.5.58:5060>
From: <tel:1234>;tag=4069ac35000c5ff8
To: <tel:2345>
Call-ID:7f0000113ce4069ac35000c5440
CSeq: 1 INVITE
Content-Length: 155
Content-Type: application/sdp