(Common Part Convergence Sublayer)cost / 开销corelayer / 核心层convergence / 收敛console port / 控制口端口coimnection ID / 连接IDconnectionless / 无连接connection-oriented / 面向连接的control direct VCC / 控制直接VCCcontrol distribute VCC / 控制分配VCCcongestion collapse / 拥塞崩溃congestion ...