Click the Exhibit button. The exhibit shows a 15454/15216 DWDM system and alarm indications. What are two possible sources of trouble shown in the system?（） (Choose two.)

多项选择题What are three relevant design considerations when using the 15216 EDFA? （）(Choose three.)

A. dispersion
B. Optical SNR
C. span attenuation
D. four wave mixing
E. receiver sensitivity

单项选择题UPSR protection switching is initiated by （）, while BLSR is initiated by （）.

A. the K1 SONET byte； the K2 SONET byte
B. the K2 SONET byte；the K1 SONET byte
C. transmitter switching；receiver detection
D. Line Overhead bytes；Path Overhead bytes
E. Path Overhead bytes；Line Overhead bytes

单项选择题On an ONS 15454 node you can tunnel an （）.

A. SDH circuit over a SONET network delivering it as an SDH signal
B. SDH circuit over a SONET network delivering it as a SONET signal
C. SONET circuit over an SDH network delivering it as an SDH signal
D. SONET circuit over an SDH network delivering it as a SONET signal

单项选择题In order to avoid misconnections due to a failed node in a Bidirectional Line Switched Ring (BLSR), Alarm Indication Signals (AISs) are sent on every channel normally terminating in that node. What is the name of this process?（）

A. trunking
B. squelching
C. nodal bypass
D. bridge and roll
E. node failure insertion

单项选择题How is UPSR and BLSR traffic rerouted during a protection switch when a complete fiber cable cut occurs?（）

A. Traffic is switched from the first node receiving the AIS indication.
B. Traffic is switched from the far side of the failure, allowing handshaking to occur.
C. UPSR traffic is switched from the terminating node, BLSR traffic is rerouted from the originating node in the ring.
D. UPSR traffic is switched from the terminating node, circuit by circuit. BLSR traffic is rerouted from the last reachable node in the ring.