Hi,

----- Original Message ----- 
From: <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Thursday, November 14, 2002 5:03 PM
Subject: RE: [ASN.1] BER: combinations of implicit/explicit tagging


> Argh,
> 
> in the 3rd example I wrote:
> > I think the two tags [APPL 1] and [APPL 2] have to be encoded for T1.
> this should actually read:
> I think the two tags [APPL 1] and [APPL 3] have to be encoded for T1.
> 
> Sorry,
> Hans-Dieter
> 
> -----Original Message-----
> From: Doll, Hans-dieter 
> Sent: Thursday, November 14, 2002 10:48 PM
> To: [EMAIL PROTECTED]
> Subject: [ASN.1] BER: combinations of implicit/explicit tagging
> 
> 
> Hi,
> 
> given the following definition:
> T1 ::= [1] IMPLICIT T2
> T2 ::= [2] IMPLICIT T3
> T3 ::= INTEGER
> I do understand that for T1 only one tag [APPL 1] has to be encoded.

Tag should be context specific 1 not APPLICATION 1.

"10 0 00001" L V

> But I'm a little bit unsure about:
> T1 ::= [1] IMPLICIT T2
> T2 ::= [2] EXPLICIT T3
> T3 ::= INTEGER
> From my intuition I would say two tags have to be encoded for T1:
> [APPL 1] and [UNIV 2]. Right?

Context specific 1 and UNIVERSAL 2

"10 1 00001" L "00 0 00010" L V

> Given a more complex definition:
> T1 ::= [1] IMPLICIT T2
> T2 ::= [2] EXPLICIT T3
> T3 ::= [3] IMPLICIT T4
> T4 ::= INTEGER
> I think the two tags [APPL 1] and [APPL 2] have to be encoded for T1.
> Right?

Context specific 1 and Context specific 3.
"10 1 00001" L "10 0 00011" L V

L : Length
V : Value

Rajul Gupta
OSS Nokalva 
[EMAIL PROTECTED]
1-732-302-9669 (x-137)
http://www.oss.com

> Sorry, I read the specs and books but still am not sure whether
> I really groked this.
> 
> Thanks in advance,
> Hans-Dieter Doll
> 
> 

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