New T.35

Paul Long Plong at SMITHMICRO.COM
Mon Jun 28 11:21:30 EDT 1999


Could we run into problems with some country actually using the extension
field? (I think the US always defines it to be zero.) I don't see any other
alternative, though.

Paul Long
Smith Micro Software, Inc.

        -----Original Message-----
        From:   Paul E. Jones [SMTP:paul.jones at TIES.ITU.INT]
        Sent:   Monday, June 28, 1999 9:31 AM
        To:     ITU-SG16 at MAILBAG.INTEL.COM
        Subject:        New T.35


        As many of you know, the latest T.35 document supports more than 254
        codes.  In the newest document, T.35 says that one or two octets may
be used
        to indicate the country code.  If the first octet contains 1111 1111,
        second octet will contain the country code.

        Unfortunately, the syntax in H.245 does not utilize extension markers,
        there is no place to hold second octet for the country code.
Therefore, I
        would like to propose that, both for H.225.0 and H.245, we change the
        comments in the ASN.1 from:

         t35CountryCode    INTEGER(0..255),   -- country, as per T.35
         t35Extension      INTEGER(0..255),   -- assigned nationally
         manufacturerCode  INTEGER(0..65535), -- assigned nationally

        to the following

         t35CountryCode    INTEGER(0..255),   -- country, as per T.35 Annex A
         t35Extension      INTEGER(0..255),   -- assigned nationally, unless
                                              -- t35CountryCode is 1111 1111,
                                              -- which case this field shall
                                              -- contain the country code
                                              -- in T.35 Annex B
         manufacturerCode  INTEGER(0..65535), -- assigned nationally

        This may be a perversion of the t35Extension field, but we have a
        number of options if we wish to support the usage of two octets for a
        country code in H.245.

        What are your opinions?

        Best Regards,

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