对用户小交换机中继线自动寻线的英文

private branch exchange hunting

• 对:    answer; reply
• 用户:    user; subscriber; ...
• 小:    small; little; pet ...
• 交换机:    exchange board; sw ...
• 中继线:    junction line; rel ...
• 自动:    voluntarily; of on ...
• 寻:    look for; search; ...
• 线:    thread; string; wi ...