http://www.larmouth.demon.co.uk/tutorials/tagging.ppt
John L
Conrad Sigona wrote:
Hello.Now I started to study ASN.1.So I still beginner of ASN.1.Please () that I'm not familiar with ASN.1. Now I can't understand the meaning of tagged type. According to "A Layman's Guide to a Subset of ASN.1, BER, and DER",it describes "tagged type is derived from another type".But what does "another type" mean?With regard to the following example,why "Version" or "Extensions" type shuold be defined as explicitly tagged type.From which type the "Version" or "Extensions" type is derived?I can't find the "underlying type".And what is the difference of explicitly tagged type and implicitly tagged type.Why do we need to distinguish the usage of them. By the way how can we assign the tag number within the class?Is there some rule?
I know this kind of question is very primitive.But Could someone teach me.
Dear Mr. Liu:
You would do well to download one (or both) of the ASN.1 textbooks available free of charge at www.oss.com.
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