Question: What is a primary function of the Media Gateway Function (MGW) in the IP Multimedia Subsystem (IMS) for bearer interworking with other networks?
Option 1: To manage Quality of Service (QoS) parameters for voice bearers across different networks.
Option 2: To support transcoding between codecs used by the User Equipment (UE) and those used in external networks.
Option 3: To handle authentication protocols for secure inter-network communications.
Option 4: To route signaling messages exclusively for video calls.
Explanation: In the context of IMS bearer interworking, transcoding is crucial for ensuring seamless voice communication between different networks that may utilize incompatible audio codecs. The MGW's role in supporting this transcoding function enables end-to-end voice connectivity or facilitates it through conversion, thereby allowing interoperability between the IM CN subsystem and other networks (e.g., PSTN, ISDN). This highlights the importance of codec compatibility in maintaining uninterrupted service across heterogeneous network environments.