Users at Both the New York and Los Angeles Sites

Users at both the New York and Los Angeles sites are complaining that VoIP is not working. Other network services at those sites and users at other sites seem to be unaffected. What are the first two things you should investigate to find the cause of this issue? (Choose two.)

A) the current status of the New York and Los Angeles sites
B) the current bandwidth utilization for the circuits to New York and Los Angeles
C) the current CPU load for the routers in New York and Los Angeles
D) recent changes to the router configurations in New York and Los Angeles
E) the software versions on the Call Managers supporting New York and Los Angeles