What is codec negotiation?

What is codec negotiation?

• A. Setting a fixed codec on both ends
• B. Re-encoding all media to a single format
• C. The process where endpoints choose a mutually supported codec from their offered lists
• D. Transcoding only when bandwidth is low

Answer: (C)

The main idea being tested is how two endpoints decide which codec to use by negotiating during setup. Codec negotiation is the process where each endpoint tells the other which codecs it can support and then both sides select a codec that is available to and compatible with both. This ensures the media stream can be encoded and decoded by both parties without errors, and it often aims to pick the best possible quality the network and devices can handle. This is why the best choice is the description of endpoints choosing a mutually supported codec from their offered lists. It captures the dynamic, mutual agreement that happens during session setup, typically using signaling like SIP with SDP, where capabilities are exchanged and a common codec is chosen. The other ideas miss the essential point. Fixing a codec on both ends bypasses negotiation and reduces flexibility. Re-encoding all media to a single format suggests transcoding after the fact rather than agreeing on a common format during setup. Transcoding only when bandwidth is low describes adaptive processing that happens after the session starts, not the negotiation to establish a shared codec.

The main idea being tested is how two endpoints decide which codec to use by negotiating during setup. Codec negotiation is the process where each endpoint tells the other which codecs it can support and then both sides select a codec that is available to and compatible with both. This ensures the media stream can be encoded and decoded by both parties without errors, and it often aims to pick the best possible quality the network and devices can handle.

This is why the best choice is the description of endpoints choosing a mutually supported codec from their offered lists. It captures the dynamic, mutual agreement that happens during session setup, typically using signaling like SIP with SDP, where capabilities are exchanged and a common codec is chosen.

The other ideas miss the essential point. Fixing a codec on both ends bypasses negotiation and reduces flexibility. Re-encoding all media to a single format suggests transcoding after the fact rather than agreeing on a common format during setup. Transcoding only when bandwidth is low describes adaptive processing that happens after the session starts, not the negotiation to establish a shared codec.