Its an identifier just like callStart and callEnd. I've spent many a day wondering about these.
In a programming language you have builtin types. Then you define your own types. Then you declare variables - each must be declared as some previously defined type whether builtin or user defined. However in ASN.1 you have components. These are more like members of big structures (C structs) - often the whole spec sums up to one big struct - though most often a kind of "union" of many types. The use of variables is rare in protocol specs as I have come across them. They have this odd name "value" in ASN.1 (correct me if this was changed). To me a variable can take one of a set of values - this actually constitites the actual type of the variable. All written from the top of my head ! Pls correct if outdated or wrong ! Steen Oluf Karlsen Soholtvej 6 Vester Vandet DK-7700 Thisted Danmark Tel +45 97 97 72 72 email [EMAIL PROTECTED] -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: 19. december 2003 07:33 To: [EMAIL PROTECTED] Subject: [ASN.1] When Sequence Hi All, I am very new to this mailing list and also to ASN.1 syntax. I just come across "when SEQUENCE" syntax in one of the message type of RASV4. Following is a syntax of that message - CapacityReportingSpecification ::= SEQUENCE { when SEQUENCE { callStart NULL OPTIONAL, callEnd NULL OPTIONAL, ... }, ... } I was just wondering about what is the significance of "when" as a prefix to SEQUENCE ? Can anybody tell me about this. Thanks in advance Upma
