FR:  Frame Relay  帧中继

VC:  Virtual Circuit  虚电路

PVC:  Permanent Virtual Circuit  永久虚电路

DLCI:  Data Link Connection Idenfier  数据链路连接标示符

LMI:  Local Management Interface  本地管理接口

CIR:  Committed Information Rate  承诺信息速率

BC:  Committed Burst  承诺突发

BE:  Excess Burst  超量突发