1. In the following diagram, PCMU and G729 are offered. Ingress policy removes G729 and allows PCMU. The egress policy adds G729 and strips PCMU from offered SDP and forwards it on to the answerer (ptime is also removed because the last codec was removed).

   The SDP answer agreed to use G729 and adds PCMA. The egress policy then strips PCMA from the SDP answer. At this point, the top codec in A1, G729 is checked against O1. Since G729 is not present in O1, it is transcoded to PCMU.

   
2. In the following diagram, GSM is in the original SDP offer. It is then passed through to O1. Egress policy adds G729 and retains ptime from GSM and sends this to the answerer as O2.

   The SDP answer agrees to use G729 and GSM, but prioritizes GSM. The egress policy allows both codecs through, unchanged. Because A1 and O1 both have GSM, it is used for the non-transcoded call. Ptime is copied from A0 to the result.

   
3. In the following diagram, G729 in the original SDP offer. Because once G729 is removed, no non-signaling are left in O1, thus the call is rejected.
   
4. In the following diagram, GSM is in the original SDP offer. It is then passed through to O1. Egress policy adds G729 and retains ptime from O1 and sends this to the answerer as O2.

   The SDP answer states that the answerer wants to use PCMU. This is a violation of the RFC3264. Therefore the call is rejected.

   

   In this example, when the negotiation fails, the Oracle Communications Session Border Controller sends a 500 message to the offerer and a BYE message to the answerer.

5. In the following diagram, GSM is in the original SDP offer. It is then passed through to O1. Egress policy adds G729 and retains ptime from O1 and sends this to the answerer as O2.

   The SDP answer replies with G722 G729 GSM and PCMU. PCMU is stripped by policy, G722 is moved to the back of the answer because it was not offered. The top A1 codec was not in O1, and was added by egress policy, therefore the call is transcoded between GSM and G729.

   

1. In the following diagram, a video m= line is offered. The ingress policy disables the video m= lines. With no enabled m= lines left, the call is rejected.
   
2. In the following diagram, G729 and video are offered to the Oracle Communications Session Border Controller. Ingress policy allows G729 and disables the video m= line. The egress policy adds iLBC and G726-16, and then orders the codecs according to the order-codecs parameter. The ptime is maintained between O0 and O2. Both added codecs are allocated dynamic payload types in the order they appear in their m= line. A disabled Video m= line is passed on to the answerer.

   The SDP answer agreed to use iLBC, G729, and adds PCMU, and reorders them as stated. The disabled video m= line is maintained. At this point, the top codec in A1, iLBC is used and transcoded with the top codec in O1, G729.

   
3. In the following diagram, G729 and video are offered to the Oracle Communications Session Border Controller. Ingress policy allows G729 and disables the video m= line. The egress policy adds iLBC and G726-16, and then orders the codecs according to the order-codecs parameter. The ptime is maintained between O0 and O2. Both added codecs are allocated dynamic payload types in the order they appear in their m= line.

   The SDP answer only wants to use PCMU and PCMA. The egress policy removes PCMA and passes only PCMU to the offerer. Because PCMU was in O1 and is now the only codec in A1, it is used, and no transcoding is used between the endpoints.

   
4. In the following diagram, G726-16 and telephone-event are offered to the Oracle Communications Session Border Controller. Ingress policy allows both codecs. The egress policy adds iLBC, and then orders the codecs according to the order-codecs parameter.

   The SDP answer agreed to use all codecs, but reorders them with G726-16 in the top position. Because G726-16 is the top codec in A1, and it is also present in O1, it is used for this call without any transcoding.

   

1. In the following diagram, the answerer sends a reINVITE after a previous transcoding session was established. The original offerer and answerer swap roles. The new offerer is rejected by Oracle Communications Session Border Controller and the call reverts to the state negotiated in the original SDP negotiation.
   

1. In the following diagram, telephone event was offered by the offerer but was stripped by ingress policy. telephone-event was not added by the egress policy because the remaining audio codec in O1 was not DTMFable. G729 was the only codec forwarded on to the answerer.

   The SDP answer agreed to use the remaining audio codec, G729. A0 is unaltered by egress policy, and forwarded as the Result to the offerer. Therefore, G729 is used in both the ingress and egress realms, the call does not support RFC 2833, and the call is not transcoded.

   
2. In the following diagram, telephone event was offered by the offerer but was stripped by ingress policy. telephone-event was added by the egress policy because the remaining audio codec in O1 was DTMFable. PCMU and telephone-event are then forwarded on to the answerer. Note that the telephone-event payload type is added with the lowest available dynamic type number.
   

   This case illustrates when the answerer supports audio and RFC 2833, but the offerer supports audio with inband DTMF. The Oracle Communications Session Border Controller transcodes between RFC2833 in the egress realm to in-band DTMF on the ingress realm.

3. In the following diagram, telephone event was offered by the offerer but was stripped by ingress policy. telephone-event is added by the egress policy because the remaining audio codec in O1 was DTMFable. PCMU and telephone-event are then forwarded on to the answerer. Note that the telephone-event payload type is added with the lowest available dynamic type number.
   

   The SDP answer only agreed to use PCMU. When A0 reaches the egress policy, it is passed along through the Oracle Communications Session Border Controller to the offerer. Because telephone-event was not answered by the answerer and not supported in O1, it can’t be used. Transcoding is therefore not used for this call.

4. In the following diagram, telephone event was offered by the offerer and was stripped by ingress policy. Since PCMA was also stripped by the egress policy, leaving no non-signaling codecs, the call is rejected. A 500 message is sent back to the offerer.
   

1. In the following diagram, telephone event and PCMU are offered by the offerer. They are both passed to O1, and PCMA is added as it is sent to the answerer. The SDP answer, A0 disables all codecs but PCMU.
   

   The Oracle Communications Session Border Controller adds telephone-event to the result because it is listed on the ingress policy’s add-codecs-on-egress parameter and present in the offerer’s SDP.

   Note:

   This is the only time the add list of an ingress policy is utilized as a check.

   The result SDP includes PCMU and telephone-event in the ingress realm, which is transcoded to PCMU with in-band DTMF in the egress realm.

2. In the following diagram, telephone event and PCMU are offered by the offerer. They are both passed to O1, and PCMA is added as it is sent to the answerer. The SDP answer supports all three codecs offered, with PCMA added on top.
   

   The answerer responds with PCMA as the preferred codec in A0. The Oracle Communications Session Border Controller compares A1 to O1 to make the transcoding decision. PCMA is the top codec in A1 and is transcoded to PCMU, the top codec in O1. Also, because telephone-event is supported by both sides of the call, it is passed through without any transcoding necessary.

   This case illustrates when both endpoints are capable of sending and receiving telephone-event. Regardless of whether the audio portion of the call is transcoded, the telephone-event messages are passed through the system untouched, thus not requiring transcoding resources. This is known as telephone-event pass-through.

G711 Fall Back (G711FB) is an internal codec that encompasses PCMU and PCMA for carrying fax information in FAXable codecs. You must configure the G711FB codec for either PCMU or PCMA for when the Oracle Communications Session Border Controller inserts a FAXable codec in SDP. G711FB is used only for FAX transcoding scenarios.

To define G711 FB, create a media profile configuration element named g711fb and set the payload-type to 0 or 8.

1. In the following diagram, there are three offer-answer exchanges. Initially a PCMU-to-PCMU session is negotiated. Next, a T.38 to PCMU session is negotiated. Finally, the session reverts to non-transcoded PCMU to PCMU state.
   

1. In the following diagram, T.38 is offered to the Oracle Communications Session Border Controller. A second m= line was added to O1 that included a G711FB codec (PCMU).

   The SDP answer agreed to PCMU, but disabled T.38. When the Oracle Communications Session Border Controller forwarded the SDP in A1 to the answerer, it stripped the second m= line. Because A1 rejects T.38 m= line, but accepts the PCMU m= line, FAX transcoding is enabled.

   
2. In the following diagram, T.38 is offered to the Oracle Communications Session Border Controller. A second m= line was added to O1 that included a G711FB codec (PCMU).

   The SDP answer agreed to PCMU and T.38. Because both O1 and A1 support T.38, the call proceeds without transcoding.

   

1. In the following diagram, PCMU and telephone-event codecs are received by Oracle Communications Session Border Controller .The egress codec policy has PCMU, G729 and T.38 add-codecs-on-egress.
   Since there is a faxable codec in the SDP offer and T.38 in add-on-egress, the non-faxable codec G729 is stripped and T.38 is added to egress offer.

   In the A0 answer the audio m-line is zero indicating disabled and the port for the image m-line is non-zero (20000) so the called party has selected T.38. Hence PCMU in realm A is transcoded to T.38 in realm B.
2. In the following diagram, PCMU and T38 are received by the Oracle Communications Session Border Controller. The egress codec policy has PCMU, G729, and T.38 add-codecs-on-egress.

   T.38 is present in the O0 offer, and therefore will not be explicitly added by the egress codec policy to the O2 Offer. The logic to remove non-faxable codecs is only invoked when T.38 is added by the add-codecs-on-egress parameter. In this example, T.38 is not added since is already present in SDP. With PCMU and T.38 received, G729 as a non-faxable codec is not removed. Therefore, PCMU, T.38, and G729 are all present in the O2 SDP offer sent to the answerer.

   In the A0 answer, the audio m-line port is 0 indicating that audio is disabled, and the port for the image m-line is nonzero (20000), thus the called party has selected T.38. In the A1 answer the OCSBC send the audio m-line port as 0 indicating that audio is disabled, and the port for the image m-line is nonzero (20000). This set-up results in a non-transcoded T.38 -OCSBC -T.38 fax call.

1. In the following diagram, PCMU is offered in the ingress realm with 30ms ptime, and the egress realm is forced to use 40ms ptime. PCMA is added as the top codec for the egress realm.

   The Oracle Communications Session Border Controller enables transcoding between the ingress realm (PCMU) and the egress realm (PCMA) and the ptimes as negotiated are also maintained.

   
2. In the following diagram, PCMU is offered in the ingress realm with a ptime of 30ms, and forced to 40 ms in the egress realm by policy.

   The answerer chooses to use PCMU with a 20 ms ptime. Thus the call is not transcoded, but it is transrated from 30ms in the ingress realm to 20ms in the egress realm.

   
3. In the following diagram, PCMU and G723 are offered in Realm A. The top codec’s ptime (30ms) is implied as the one for the ingress realm. The Oracle Communications Session Border Controller adds PCMA to the SDP offer with a 40ms ptime.

   The answerer chooses to use PCMU with a 40 ms ptime. Thus the call is transrated from 30ms in the ingress realm to 40ms in the egress realm.

   

1. Access the media-manager-config configuration element.

   ORACLE# configure terminal
   ORACLE(configure)# media-manager
   ORACLE(media-manager)# media-manager
   ORACLE(media-manager-config)# 

2. Type select to begin editing.

   ORACLE(media-manager-config)# select
   
   ORACLE(media-manager-config)#

3. reactive-transcoding— Set this parameter to enabled for the SBC to perform reactive transcoding.

   ORACLE(media-manager-config)#reactive-transcoding enabled

4. Type done to save your configuration.