You support a customer whose network environment includes Microsoft Lync Server 2013. A firewall filters all inbound traffic from the Internet. All outbound IP traffic is permitted.
Users report voice quality problems when they attempt to communicate with external participants.
You need to ensure that Lync users are able to communicate with external participants. Which two ports should you open on the firewall? (Each correct answer presents part of the solution. Choose two.)
A. TCP port 443
B. UDP port 3478
C. TCP port 4443
D. TCP port 5061
E. TCP port 8057
