What is the maximum one-way delay, in milliseconds, between any two Cisco Unified
Communications Manager servers in a non-Session Management Edition cluster over an IP WAN?

A.
20

B.
40

C.
80

D.
160

E.
250

Explanation:
The maximum one-way delay between any two Unified CM servers should not exceed 40 msec, or 80
msec round-trip time. Propagation delay between two sites introduces 6 microseconds per
kilometer without any other network delays being considered. This equates to a theoretical
maximum distance of approximately 3000 km for 20 ms delay or approximately 1860 miles. These
distances are provided only as relative guidelines and in reality will be shorter due to other delay
incurred within the network.
http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/srnd/7x/uc7_0/models.html