00256nam a2200109Ia 4500008004100000041001200041082001100053100002100064245004900085260000600134650000600140221030s9999    xx            000 0 und d  aEnglish  a105.23  aS. Kartalopoulos 0aUnderstanding Sonet/SDHcby S. Kartalopoulos  c0  aB