拥塞控制手段（开环）：

A. 不能超出外汇局相关业务系统中尚可流入金额
B. 不能超出外汇局核定的期限
C. 电文中必须账号与户名一致
D. 贷记账户必须是资本项下账户

A. Interfaces have a default metric of 1.
B. Level 1 is intra - area and level 2 is interarea.
C. Level 1 routing is between an end system (ES) and IS while Level 2 routing is between an IS and I
D. Hosts send ISHs while routers send ESHs.
E. IS - IS is an open standard.
F. Metrics depend on interface speed.