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From: Kluger.osbunorth@XEROX.ARPA
Newsgroups: mod.telecom
Subject: Re: Local Telco X.25 PDNs
Message-ID: <851107-085744-1119@Xerox>
Date: Thu, 7-Nov-85 11:44:38 EST
Article-I.D.: Xerox.851107-085744-1119
Posted: Thu Nov  7 11:44:38 1985
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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