Which timing mode is most appropriate for an ONS 15454 that has lost its BITS-1 and optical references?（）

单项选择题You are provisioning a DS-1 circuit on an ONS 15454 2F-BLSR with a XC-10G card. Each VT1.5 connection must also terminate via the STS matrix. On the originating circuit node, how many STS ports are now available for VT1.5 circuits?（）

A.2
B.3
C.4
D.20
E.22
F.24

单项选择题A customer has 2 DS1s to add between adjacent nodes in a UPSR ring. What type of circuit should you recommend?（）

A. VT circuits
B. STS circuits
C. VT tunnel circuits
D. 1:1 protection circuits
E. 1:N protection circuits

单项选择题Click the Exhibit button. Given the information shown in the exhibit, when creating 2 DS1 circuits, how many STS ports are used on the VT1.5 matrix at Node 1 as VT circuits and how many are used after using VT tunnels?（）

A.2；0
B.3；2
C.3；5
D.4；0
E.6；0
F.6；2

单项选择题A customer wants to create a 1:1 protection group with a DS3N-12 card. Which card slots would allow for a 1:1 protection?（）

A. Slot 2 and Slot 4
B. Slot 4 and Slot 6
C. Slots 5 or 13 only
D. Slot 16 and Slot 17

单项选择题Click the Exhibit button. Which type of protection is shown in the exhibit?（）

A.1+0
B.1+1
C.1：1
D.1：N