See answers in original text below.
Regards,
Ed Day
Principal Engineer
Objective Systems, Inc.
[EMAIL PROTECTED]
(484) 875-3020 (main)
(610) 608-4930 (mobile)
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----- Original Message -----
From: "tong" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, July 17, 2002 11:18 PM
Subject: [ASN.1] doubts about context tag
> HI all
>
> again GSM-MAP
> example:
> UpdateLocationArg ::= SEQUENCE {
> msi MSI,
> msc-Number [1] ISDN-AddressString,
> vlr-Number ISDN-AddressString,
> lmsi [10] LMSI OPTIONAL,
> extensionContainer ExtensionContainer OPTIONAL,
> ... ,
> vlr-Capability [6] VLR-Capability OPTIONAL }
>
> 1 why encode 1,6,10,not continuously?
There is no rule that says it has to be done this way (although it would
make more sense).
> 2 the order of context why not from small to big ? in this example is
1,10,6.
Same answer as 1)
> 3 why some subtype(vlr-Number) not have context tag?
It is not required. In this case, vlr-Number will use whatever tag is
assigned to ISDN-AddressString. If a built-in type is referenced, the
universal tag for that type will be used.
> 4 msc-Number not have OPTIONAL,so must presence,and so use context tag is
absolutely unneeded ?
That is true, it is not needed.
>
>
>
>
