On the typical access network of a bearer network, a core network device connects to two upstream CEs. CEs connect to PEs in a square shape. This access network must bear voice and signaling services. A CE must be configured with two VPNs to separate the voice and signaling services and ensure high security and QoS. The signaling service works in active/standby mode, and the voice service works in load sharing mode. The VRRP must be enabled between the CEs to terminate the signaling flow.
If the network robustness is ensured and the network architecture is rational, which of the following statements about the topological structure are true?
A . The voice service must be carried by GE links and the signaling service must be carried by FE links.
B . Instead of POS links, GE links are recommended between CEs and PEs.
C . The total link bandwidth between CEs cannot be less than that between CEs and PEs.
D . GE and FE links need to be used as the Eth-trunk between CEs to improve reliability.
Answer: A, B, C