This paper discusses technical considerations surrounding open network architecture (ONA), specifically: (1) the technical characteristics of the Public Networks (Local Exchange Carriers LATA Networks); (2) the impact of ONA success on the Public Network and some concerns that will have to be addressed in the early implementation stages; and (3) concerns for the security of the Public Network in the light of a vigorous and successful development of open network architecture. It is concluded that: (1) from a technical point of view, ONA implementation will proceed at a rate that is frustrating to some, but which is bound by the technical realities of the Public Network; (2) anything that can expedite replacing the older switching technology will help; (3) as ONA is implemented and becomes used in interesting quantities, the Local Exchange Carrier will have to evolve equipment provisioning procedures and rules and, in all probability, will purchase more equipment; and (4) thought must be given to how signaling systems are extended to ensure that the traditional integrity of the American telephone network is preserved. (GL)