Subject	English	Chinese
el.	electronic switching system control	电子交换系统控制
el.	electronic switching system flow chart	电子交换系统流程图
el.	inter-switching system interface	交换机间系统接口
IT	inter switching system interface	交换系统间接口
el.	inter-switching system interface	内部交换系统接口
el.	inter-MAN switching system interface	城域网间交换系统接口
el.	LATA switching system generic requirement	本地接人与传送区交换系统一般要求
el.	tone dial switching system control	单音拨号交换系统控制