Customized G.729 Support

The Oracle® Enterprise Session Border Controller supports the use of custom G.729 encoding for calls that require interworking between SIP and H.323. If you use a proprietary G.729 encoding format in your network, then you might need to use this feature.

When you set the acceptG729abFormat option in the global H.323 configuration, the Oracle® Enterprise Session Border Controller performs conversions like those in the following examples:

• For calls initiated in SIP, the Oracle® Enterprise Session Border Controller can parse RTP map strings such as G.729a and G.729ab in the SDP, and then map them to H.245 data types.
  • G.729a becomes g729AnnexA.
  • G.729ab becomes g729AnnexAwAnnexB.
• For calls initiated in H.323, the Oracle® Enterprise Session Border Controller can create non-standard RTP map strings such as G.729a and G.729ab from mapped H.245 data types.
  • g729 becomes G729.
  • g729AnnexA becomes G.729a.
  • g729AnnexAwAnnexB becomes G.729ab.

When you enable the acceptG729abFormat option, the Oracle® Enterprise Session Border Controller performs customized G.729 mapping in the following instances.

• For calls initiated in SIP and translated to H.323, the Oracle® Enterprise Session Border Controller:
  • Converts the SDP in an incoming SIP INVITE to a list of fastStart OpenLogicalChannel requests that are in turn included in the outgoing Setup message.
  • Converts the list of fastStart OpenLogicalChannelAck responses (which can be received in any message up to and including the Connect message) to SDP sent with a SIP response.
• For calls initiated in H.323 and translated to SIP, the Oracle® Enterprise Session Border Controller:
  • Converts the list of fastStart OpenLogicalChannel requests to SDP in the outgoing SIP INVITE.
  • Converts SDP in a SIP response (such as a 200 OK) to the list of fastStart OpenLogicalChannelAck responses included with the callProceeding, Progress, Alerting, or Connect message. This depends on when the SDP is received on the SIP side.
• For all IWF calls regardless of initiating protocol, the Oracle® Enterprise Session Border Controller:
  • Converts SDP on the SIP side to the terminalCapabilitySet message to be sent on the H.323 side.

Also note that when the format is G729, the Oracle® Enterprise Session Border Controller maps it to g729wAnnexB if the a=fmtp:18 annexb=yes attribute is present. When the a=fmtp:18 annexb=no attribute is present, the Oracle® Enterprise Session Border Controller maps G729 to g729. And with no a=fmtp:18 annexb=no attribute, the Oracle® Enterprise Session Border Controller also maps G729 to g729 when this option is enabled.

The Oracle® Enterprise Session Border Controller also maps G729 to g729 because pure G729 with static payload type 18 does not include an fmtp attribute where annexb=no.