IWF H.245 Signaling Support for G.726

In addition to providing G.726 support for pure SIP and pure H.323 calls, the Oracle® Enterprise Session Border Controller supports the G.726 payload type for H.245 and calls that require interworking (IWF) between SIP and H.323.

For IWF calls using ITU-T G.726 as the audio codec, the SIP call leg requires G.726 in the SDP. The H.323 side of the call signals G.726 (in the H.245 openLogicalChannel and TerminalCapabilitySet messages) by including a GenericCapability defining G.726 as the codec. In the GenericCapability, the capabilityIdentifier and maxBitRate parameters identify G.726. While a capabilityIdentifier with 0.0.7.726.1.0 designates G.726, the maxBitRate designate the data transmission rate.

Codec	Max Bit Rate	Data Rate
G726-16	160	16 kbit/s
G726-24	240	24 kbit/s
G726-32	320	32 kbit/s
G726-40	400	40 kbit/s

To support G.726 for IWF calls, the Oracle® Enterprise Session Border Controller converts the G726-X value in the SDP of SIP messages to a GenericCapability structure in H.323/H.245 messages, and the conversion works the same way in reverse.

H.245 and G.726 Configuration

To enable this feature, you do need to set up media profile configurations appropriately. Media profiles now allow you to set the configuration to any of the four G.726 encodings (as defined by ITU G726 Annex B and RFC 3551). You must create one media profile for each of the four different supported data rates. In addition, you are also required to set a genericAudioCapability media profile.

Media Profile for H.245 and G.726 Configuration

To set a media profile for H.245 and IWF G.726 support:

1. In Superuser mode, type configure terminal and press Enter.

   ORACLE# configure terminal
   ORACLE(configure)#

2. Type session-router and press Enter.

   ORACLE(configure)# session-router

3. Type media-profile and press Enter.

   ORACLE(session-router)# media-profile
   ORACLE(media-profile)#

4. name—Set the name of the media profile to G726-16. Values to support this feature are: G726-16, G726-24, G726-32, and G726-40.
5. media-type—Set the media type to use for this media profile; for generic video, set this parameter to audio. Valid values are:

   • audio | video | application | data

6. payload-type—Set the payload type to use for the generic video media profile.
7. transport—Set the transport type to use for the generic video media profile. The default value is RTP/AVP. Valid values are:

   • UDP | RTP/AVP

8. Complete the rest of the media profile configuration as needed.
9. Save and activate your configuration.

   The following is a sample of a media profile configuration for H.245/IWF G.726 support:

   media-profile
           name                           g726-40
           media-type                     audio
           payload-type                   105
           transport                      RTP/AVP
           req-bandwidth                  0
           frames-per-packet              0
           parameters
           average-rate-limit             0
           sdp-rate-limit-headroom        0
           sdp-bandwidth                  disabled

Media Profile Configuration for Generic Audio Support

To set a media profile for generic audio support:

1. In Superuser mode, type configure terminal and press Enter.

   ORACLE# configure terminal
   ORACLE(configure)#

2. Type session-router and press Enter.

   ORACLE(configure)# session-router

3. Type media-profile and press Enter.

   ORACLE(session-router)# media-profile
   ORACLE(media-profile)#

4. name—Set the name of the generic audio media profile to genericAudioCapability. There is no default for this parameter.
5. media-type—Set the media type to use for this media profile; for generic video, set this parameter to audio. Valid values are:

   • audio | video | application | data

6. payload-type—Set the payload type to use for the generic audio media profile.
7. transport—Set the transport type to use for the generic audio media profile. The default value is RTP/AVP. Valid values are:

   • UDP | RTP/AVP

8. Complete the rest of the media profile configuration as needed.
9. Save and activate your configuration.

   The following is a sample of a generic audio media profile configuration:

   media-profile
           name                           genericAudioCapability
           media-type                     audio
           payload-type                   104
           transport                      RTP/AVP
           req-bandwidth                  0
           frames-per-packet              0
           parameters
           average-rate-limit             0
           sdp-rate-limit-headroom        0
           sdp-bandwidth                  disabled