00422nam a2200157Ia 450000100060000000800410000602000180004704000130006508200210007810000170009924500640011626000440018030000110022454600070023565000220024218540140407s9999    xx            000 0 und d  a0-471-92800-3  cPK-LaUMT  a 621.3822bHEL-D  aGilbert Held  aDigital networking and t-carrier multiplexingcGilbert Held  aNew York,USA:bJohn Wiley & Sons,c1990  a156 p.  aEN  aComputer networks