FECN,BECN,DE是什么概念???<br><br><br>The Frame relay circuit between TestKing1 & TestKing2 is experiencing congestion. Which type of notification are used to alleviate the congestion? (Choose three)<br>A. FECN<br>B. CIR<br>C. BECN<br>D. DE<br>E. DLCI 100 is Down<br><br>ACD