Online Access Free H31-311 Practice Test

Optical supervisory channels are intended for the supervisory of WDM optical transmission systems. In ITU-T recommendations, 1510 nm wavelengths at a ( ) rate are preferentially used.

• A.192 kbit/s
• B.64 kbit/s
• C.576 kbit/s
• D.2Mbit/s

In ITU-T G.692 recommendations, the allowed channel frequency is based on the reference frequency ( ) and the channel spacing can be 100 GHz, 50 GHz, or 25 GHz.

• A.193.1 THz
• B.194.1 THz
• C.192.1 THz
• D.196.1 THz

The fiber core refractive index n1 must be ( ) the cladding layer refractive index n2, which is a necessary condition for transmitting optical signals in optical fibers.

• A.lower than
• B.equal to
• C.higher than

Which of the following is the multiplexing mode of SDH?

• A.Flexible mapping
• B.Asynchronous multiplexing
• C.Flexible mapping and asynchronous multiplexing
• D.Flexible mapping and synchronous multiplexing

When a VLAN-based service type is configured, which of the following functions must be enabled on the port?

• A.Auto-negotiation mode
• B.Entry detection
• C.Broadcast packet suppression
• D.Flow control