Kluger.osbunorth@XEROX.ARPA (11/07/85)
Regarding the message about local Telcos starting up their own X.25 PDNs (Public Data Networks). The comment was that long haul X.25 might be done by other companys, same as long haul voice is done by the carriers, not the telcos. Well, I sure hope not. Give me an end-to-end PDN any day. The interface within the voice system between local and longhaul carriers is a whole lot better that the equivalent in X.25 land (X.75). In my experiences with X.75 (A US PDN to Japan via X.75 and a US PDN to England via X.75) it hasn't yet worked right. And the PDN isn't real helpful about fixing the problems in their X.75 gateway either. It works okay for simple X.25 calls with pkt size = 128, window of 2; but anything better than that tends to fail. The 1984 version of the X.25 and X.75 specs will help, but many PDNs aren't yet implementing version 1980! Larry Kluger