Bibliografia

SDH

http://es.wikipedia.org/wiki/Jerarqu%C3%ADa_digital_s%C3%ADncrona

http://www.monografias.com/trabajos15/jerarquia-digital/jerarquia-digital.shtml

http://spanish.alibaba.com/product-gs/stm-1-sdh-equipment-flexibly-configured-with-10-100m-ethernet-e1-2048kbps-rs232-v-35-567518377.html

http://ingenieria.udea.edu.co/~avendano/docs/datos/SDH_y_SONET.doc

ATM

http://www.angelfire.com/wi/ociosonet/29.html

http://es.wikipedia.org/wiki/Modo_de_Transferencia_As%C3%ADncrona

http://www2.rhernando.net/modules/tutorials/doc/redes/atm.html

http://www.cisco.com/en/US/products/hw/switches/ps1893/products_tech_note09186a0080174981.shtml

Frame relay

http://www.movistar.es/qx/Nav/qxTCNavZM/1,,v_idioma+es+v_segmento+AHOG+v_producto+1061,00.html

http://www.zonavirus.com/articulos/que-es-frame-relay.asp

http://www.cisco.com/en/US/docs/internetworking/technology/handbook/Frame-Relay.html

http://www.angelfire.com/wi/ociosonet/7.html

http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&docid=eM7l88nWMSdkzM&tbnid=ak9Ae6mW8KFyAM:&ved=0CAEQjxw&url=http%3A%2F%2Fspanish.alibaba.com%2Fproduct-tp%2Fblack-box-lr1530a-r3-series-500-branch-office-frame-relay-router-base-123691375.html&ei=4S-eUv6EBqjF0QXO4YDICw&bvm=bv.57155469,d.ZGU&psig=AFQjCNGVQdVnx-mTVPnURtMBzTz7kzFmLw&ust=1386185052850684