多项选择题
A. It protects signals against node failures between rings.
B. It protects signals against node failure within a single ring.
C. It allows for traffic to be preempted when a ring switch occurs.
D. Traffic can be dropped and continued at interconnecting nodes.
E. It protects preemptible traffic from being dropped when a ring switch occurs.
单项选择题 What protocol enables Ethernet over SONET/SDH encapsulation interoperability between the G-series and ML-series Ethernet cards?（）
单项选择题 Click the Exhibit button. In the DCN connection shown in the exhibit, all non-GNE nodes are located on different subnets from the GNE. There are no static routes or external OSPF on any elements. CTC Workstation and GNE have Cisco Router as their default gateway. Can the CTC workstation see the entire SONET network?（）
多项选择题 Which three timing modes are supported on the ONS 15454 shelf? （）(Choose three.)