According to the news of Microsoft Official website, Microsoft 74-338 exam will be retired on March 30, 2016.

Knowing Microsoft 74-338 exam topics are valuable in your preparation. 

Analyze and troubleshoot Enterprise Voice(25%-30%)

Troubleshoot conferencing and application sharing (20-25%)

Troubleshoot IM and Presence (20-25%)

Troubleshoot infrastructure and tools (20-25%)