On Fri, 23 Jan 2004, Ed Day wrote: > We have a question on size constraint syntax. In the RANAP > specification, the following declaration exists: > > TransportLayerAddress ::= BIT STRING (SIZE (1..160), ...) > > According to X.680, an extensible size should be written as follows: > > (SIZE (1..160,...)) > > We are wondering how the above definition should be treated. X.680 > Annex G gives several examples of extensible situations, but this one > does not appear to be covered. It would appear to us that in the case > above, the ... is indicating that additional constraints can be added in > the future and would not apply to the 1..160 range. How should this be > interpreted?
The two syntaxes are equivalent in versions of ASN.1 prior to 2002, but the normative text of X.680:2002 accidentally indicates that (SIZE (1..160), ...) is extensible and (SIZE (1..160, ...)) is not extensible (see clause 46.3). This mistake was recognized before publication of ASN.1:2002, but it was too late in the process publication to get the right text in. I expect that this will be corrected at the ASN.1 standards meeting that is being held in Paris this week. ------------------------------------------------------------------------- Bancroft Scott Toll Free :1-888-OSS-ASN1 OSS Nokalva International:1-732-302-0750 [EMAIL PROTECTED] Tech Support :1-732-302-9669 x-1 1-732-302-9669 x-200 Fax :1-732-302-0023 http://www.oss.com
