On Wed, 17 Jul 2002, tong wrote:
hi all
In GSM-MAP(ASN.1BER IMPLICIT),I have a doubt about CHOICE:
example 1:
Ext-SS-InfoList ::= SEQUENCE SIZE (1..maxNumOfSS) OF
Ext-SS-Info
Ext-SS-Info ::= CHOICE {
forwardingInfo [0] Ext-ForwInfo,
I have questions about inner subtyping. Given these two type definitions:
Parent ::= SEQUENCE
{
anOptionalThing INTEGER OPTIONAL,
anotherOptionalThing INTEGER OPTIONAL,
aRequiredThing INTEGER
}
Child ::= Parent WITH COMPONENTS { ..., anOptionalThing
Paul Long wrote:
Paul,
I guess it depends on what you mean by a new type. (The term is not
actual defined in ASN.1, but is used in the introduction and in a
normal English way when talking about defining a new type from an old
one by tagging or subtyping.)
The text is clear that tagging and
On Wed, 17 Jul 2002, Paul Long wrote:
I have questions about inner subtyping. Given these two type definitions:
Parent ::= SEQUENCE
{
anOptionalThing INTEGER OPTIONAL,
anotherOptionalThing INTEGER OPTIONAL,
aRequiredThing INTEGER
}
Child ::=
Sorry, re my mention of possible unclarity in the A::=B and clauses
15.1 and 16.1, I missed the following in Annex B:
B.2.1 The underlying model is of types, as non-overlapping containers,
that contain values, with every occurrence of the ASN.1 Type construct
defining a distinct new type (see
John,
Okay. Whew! :-)
So for my first example, PER would encode a presence bit in the preamble
bit-map for anOptionalThing, right, even though it is constrained to be
ABSENT? And it would always be set to 0 because a value for that component
is constrained to always be absent. For my second
hello John Larmouth and Bancroft
thank you for your answers, now I have understood it much more better.
thanks.
=== 2002-07-17 18:35:00 in your letter===
Bancroft Scott wrote:
CHOICE itself does not have a tag. However, tags applied to CHOICE are
*always* EXPLICIT, even if at
HI all
again GSM-MAP
example:
UpdateLocationArg ::= SEQUENCE {
msi MSI,
msc-Number [1] ISDN-AddressString,
vlr-Number ISDN-AddressString,
lmsi[10] LMSI OPTIONAL,
extensionContainer
