Just a minute here. NEBs are requirements for Network Equipment formulated by what was the Bell Operating Companies' research arm Bellcore. (They have now been cast adrift as Telecordia).
The Operating Companies have done a good job of making sure that the requirements for their equipment were not regulated and are in effect part of the commercial negotiations that take place between the buyer and the seller. If you're a big enough seller, you can negotiate on these requirements. Ciao, Vic Boersma