Common SIP calls the SDP negotiation process includes (). (3 answers).

MsDA is the master-slave decision response message, which carries the Master or Slave flag, which refers to the state of the local side.

The role of RTP in VoIP mainly includes: real-time transmission of media information, elimination of jitter, card performance, prevention of packet loss, in a certain situation can be transmitted DTMF signals, tones and signaling.

Zone management is implemented by which of the following system modules ( ).

1080P or 720P 50/60fps is a full-frame image of 50 frames per second or 60 frames progressively, rather than an interlaced image of 50/60 fields.