Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site deepthot.UUCP Path: utzoo!watmath!deepthot!julian From: julian@deepthot.UUCP (Julian Davies) Newsgroups: net.dcom Subject: Re: X.25 - changing parameters on a remote PAD - X.29? How? Message-ID: <213@deepthot.UUCP> Date: Fri, 9-Mar-84 12:24:51 EST Article-I.D.: deepthot.213 Posted: Fri Mar 9 12:24:51 1984 Date-Received: Sat, 10-Mar-84 14:23:04 EST References: <3473@utcsrgv.UUCP> Organization: UWO CS, London Canada Lines: 26 Yes, the remote PAD can be changed with X.29 procedures. This is impossible unless you are handling the full X.25 service (Datapac-3000 in Canada). You have to be able to send and receive data packets with the Q (Qualifier) bit set. In theory, one PAD can read and control another, when both ends of the VC are on PADs, but there is no protocol defined for a user of an asynchronous terminal to read or set PAD parameters at the *far* end, only for one's own local PAD (X.28). X.29 defines uses of the call user information at VC setup, and also the user data packets with Q bit set. The latter packets have the data field in the following format (Fig. 2/X.29 (1980)) Octet 1 0 0 0 0 | msg code 2 parameter reference 3 parameter value 4 parameter reference -- if more than one .... Message code: 0010 - Set 0100 - Read 0110 - Set and read 0000 - parameter indication In PAD read messages, the 'value' fields are set zero -- the indication packet will come back with values filled in.