Dear Wayne, For Mexico you can get an everincreasing amount of information on the "Cofetel" (Federal Telecommunications Commission) web site under the Publications Oficales section among others. These includes many of the technical committee notes(recently added) . Most of the site is in Spanish. The web site address is " www.cft.gob.mx". There are also some good links from this site.
For Brazil the referenced contacts provided are good however the digital network information is still obstentively under the CPQD/Telebras and most of the technical information is there. I will go back through my records to provide the web site information that I have available sometime today or tomorrow.. Regards G. Rae Dulmage, B. Comm., President TelApprove Services Corporation (613) 257 3015
