What must the administrator configure on the firewall to stabilize this deployment?

A new administrator at Company X has deployed a VCS Control on the LAN and VCS Expressway in the DMZ to facilitate VPN-less SIP calls with users outside of the network. However, the users report that calls via the VCS are erratic and not very consistent.

What must the administrator configure on the firewall to stabilize this deployment?
A . The VCS Control should not be on the LAN, but it must be located in the DMZ with the Expressway.
B . The firewall at Company X must have all SIP ALG functions disabled.
C . The firewall at Company X requires a rule to allow all traffic from the DMZ to pass to the same network that the VCS Control is on.
D . A TMS server is needed to allow the firewall traversal to occur between the VCS Expressway and the VCS Control servers.

Answer: B