Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!BBN.COM!malis
From: malis@BBN.COM (Andy Malis)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: DDN X.25 question.
Message-ID: <8904211215.AA01341@ucbvax.Berkeley.EDU>
Date: 18 Apr 89 12:59:42 GMT
References: <99491@sun.Eng.Sun.COM>
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
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Robert,

I'm not familiar with DIS 8208.  However, let me quote from the
CCITT Red Book (1984), Rec. X.25, section 7.1, p.209:

      Facility/registration markers, consisting of a single octet
      pair, are used to separate requests for X.25 facilities ...
      from other categories as defined above [non-X.25 facilities
      which may be provided by some networks] ...

      The first octet of the marker is a facility/registration
      code field and is set to zero.  The second octet is ... set
      to zero when the marker precedes requests for:

      - non-X.25 facilities provided by the network in case of
        intranetwork calls.

      ...

      Facility/registration codes for X.25 facilities and for
      the other categories of facilities may be simultaneously
      present.  However, requests for X.25 facilities must
      precede the other requests.


So, you must first have the CCITT-defined X.25 facilities, then
the marker, and then the non-X.25 facilities provided by the
network.

Cheers,
Andy Malis
BBNCC PSN Development