Which codec could you switch to in order to get more calls to work across a DSL Link?

Switching to G.729 would be beneficial for getting more calls to work across a DSL link due to its lower bandwidth requirements compared to other codecs. G.729 is a compressed codec that operates at approximately 8 kbps, which allows multiple calls to be transmitted over the same link without overwhelming the bandwidth. Since DSL typically has limited upload bandwidth, especially in residential connections, using a codec that minimizes the amount of data sent can maximize the number of simultaneous calls.

In contrast, G.711, while providing better audio quality due to being uncompressed, consumes around 64 kbps per call. This higher bitrate can quickly saturate the available bandwidth on a DSL link, leading to call drops or lower quality. G.726 operates at variable bit rates but still tends to be more demanding than G.729. G.722, known for wideband audio quality, also requires more bandwidth, making it less efficient for maximizing the number of concurrent calls over a limited DSL connection. Therefore, G.729 is the most suitable option for improving call capacity under such conditions.