In the H.460 public and private network traversing dual SC networking, the communication between the terminal and Client GK follows the () protocol (Single choice)

When other conditions are the same, the longer the reverberation time of the room, the clearer the sound heard Clarity. () Right or Wrong

In the U1900 series unified gateways, regarding the relationship between prefix, office direction, office direction selection code and trunk, the correct statement is () multiple selection

An enterprise has purchased 3 U1960s, and the number of IP phone users is about 2500. Which networking method is suitable for these 3 U1960s? () (single choice)