NO.288 Which of the following is the common point between the two-fiber bidirectional multiplex segment shared protection ring and the four-fiber bidirectional multiplex segment protection ring?

NO.289 For monitoring channels, OSC and ESC can coexist in one network.

NO.290 The channel frequencies allowed in G.692 are based on a reference frequency of 193.1 THz, and the channel spacings are 100 GHz, 50 GHz, and 25 GHz.

NO.291 The segment overhead of STM-4 is 9+9+4 lines/frame.

NO.292 ATM nr.m consists of a maximum of n optical channels multiplexed, r means simplified function (reduced), and non-associated overhead is not supported.

NO.293 If bit errors occur in the SDH network, the service signal restored after decapsulation will definitely contain bit errors.

NO.294 Suppose 2 VC-12 time slots need to be bound to the VCTRUNK1 of the N2EFS4 board. When there are 8 VC4 slots on the N2EFS4 board, which of the following slots meets the requirements?

NO.295 The UITL single board realizes the multiplexing and demultiplexing of 50GHz and 100GHz interval signals.

NO.296 If a weak signal light and a strong pump light are transmitted simultaneously in an optical fiber, and the wavelength of the weak signal light is within the Raman gain bandwidth of the pump light, the energy of the strong pump light is combined into the oscillation mode of the silicon material of the optical fiber through stimulated Raman scattering (SRS), and then emitted at a longer wavelength, which is the wavelength of the signal light, thereby amplifying the weak signal light and obtaining Raman gain.

NO.297 The initial value of the Sequence number in the ETH PWE3 encapsulation frame format is randomly generated, and the value decreases by one each time a data packet is sent.

NO.298 Automatic Laser Shutdown (ALS): When no optical signal is received, the ALS function automatically turns off the corresponding optical module. This feature protects field maintenance personnel.

NO.299 The cascading methods for mapping Ethernet services to SDH include adjacent cascading and virtual cascading.

NO.300 Which overhead below 112 is not ODUk overhead?

NO.301 Which of the following statements about overhead bytes is incorrect?

NO.302 During service configuration, there are two time slot modes. Huawei uses interleaved time slot mode by default.

NO.303 In MSP networking, when optical fiber is connected between sites, the east optical board of the site is connected to the west optical board of the downstream site, and these sites are connected in sequence to form a ring. In this case, the direction from the east optical board of the site to the west optical board of the downstream site is the main ring direction, and the direction of the ring is the service direction.

NO.304 Which of the following is affected by changing the element ID of OSN3500 on NMS?

NO.305 Regarding the comparison between Raman amplifier and EDFA, which of the following statements is wrong?