Dear Ladies and Gentlemen,
We are creating an application to handle incoming calls by means of the system default behavior. Everything goes ok until some callers send us QoS attributes in the INVITE request. In these cases, API just replies with the same attributes and the call is canceled/dropped before initiating. One way to make it work. according to this RFC https://tools.ietf.org/html/rfc3312 , is to send 183 back to caller thus initiating a sequence of request/responses to reserve resources. All that to met preconditions for session establishment. But according to https://www.dialogic.com/~/media/manuals/docs/globalcall_for_ip_hmp_v11.pdf the only way to do it is by means of gc_SipSessionProgress( ) which only can be used in 3PCC mode.
The gc_SipSessionProgress( ) function indicates to the originator that the call will be answered. This function provides a “183 Session Progress” to the destination party request acknowledging that the call has been received but is not yet answered. Upon successful completion of this function, the call state changes from the Offered state to the Accepted state. If the call state is already in the Accepted state, then it will remain in the Accepted state.
Notes:
1. In 1PCC mode, the SDP cannot be controlled by the user application. Therefore, gc_SipSessionProgress( ) cannot be used to change any SDP information.
2. The SDP can be set and sent when operating in 3PCC mode only
While this solution is the correct one there are time and resource limitations to implement it right now.
Another way to do it is to change SDP body part of "OK status" sent back to a caller where 'a=curr:qos' and 'a=des:qos' are replicated automatically by GC API itself. Is there any function to change that SDP body or simply remove QoS attributes that don't require 3PCC mode? Is there a function to disable replication of QoS attributes?
Appreciate your help.
Best Regards.