Hello, Some one else did respond to my mail, and kindly noted that I missed the OPTIONAL keyword at the end of linkedId. Also the constraints are understandable.
Best regards, -Arun. -----Original Message----- >From: Arun Dharankar <[EMAIL PROTECTED]> >Sent: Jan 28, 2006 1:01 PM >To: [email protected] >Subject: [ASN1] ROS Invoke information object class > >Greetings... > >http://www.itu.int/ITU-T/asn1/database/itu-t/x/x880/1994-TC1/Remote-Operations-Generic-ROS-PDUs.html# >has Invoke class. The linkedId item is defined as a CHOICE, and I can also see >that Invoke has constraints defined using linkedId in one of them. > >Could someone help me understand the constraint, specifically the part using >linkedId and linkedId/opcode? >A snippet of the decoded PDU (a protocol analyzer for GSM MAP) as show below. >It seems that linkedId should be present, even if it is NULL, and I don't see >in the decoded PDU. I am sure I am not understanding something corretly. > >Best regards, >-Arun. > >Snippet of the PDU from the protocol analyzer: >octet0094 Component transaction message type: >UMTS-MAP....................... >10100001 Component Type.... INVOKE , ContextSpecific/Constr. >00110010 Component length.. 50 >00000010 Invoke ID tag..... Invoke ID tag >00000001 Invoke ID length.. 1 >00000001 Invoke ID......... 1 >00000010 LinkedID/OpCode?.. Local operation code tag >00000001 OpCode length..... 1 >00101110 Operation code.... Mo-ForwardSM >octet0102 ForwardShortMessage {} > > >Definition of Invoke: >Invoke{InvokeId:InvokeIdSet, OPERATION:Operations} ::= SEQUENCE { > invokeId > InvokeId(InvokeIdSet) > (CONSTRAINED BY { -- must be unambiguous --} ! > RejectProblem:invoke-duplicateInvocation), > linkedId > CHOICE {present [0] IMPLICIT present < InvokeId, > absent [1] IMPLICIT NULL > } > (CONSTRAINED BY { -- must identify an outstanding operation --} ! > RejectProblem:invoke-unrecognizedLinkedId) > (CONSTRAINED BY { -- which has one or more linked operations--} ! > RejectProblem:invoke-linkedResponseUnexpected) OPTIONAL, > opcode > OPERATION.&operationCode > ({Operations} !RejectProblem:invoke-unrecognizedOperation), > argument > OPERATION.&ArgumentType > ([EMAIL PROTECTED] !RejectProblem:invoke-mistypedArgument) OPTIONAL >} >(CONSTRAINED BY { -- must conform to the above definition --} ! > RejectProblem:general-mistypedPDU) >(WITH COMPONENTS { > ..., > linkedId ABSENT > } | > WITH COMPONENTS { > ..., > linkedId PRESENT, > opcode (CONSTRAINED BY { -- must be in the &Linked field of the > associated operation -- > } !RejectProblem:invoke-unexpectedLinkedOperation) > }) > > > >_______________________________________________ >ASN1 mailing list >[email protected] >http://lists.asn1.org/mailman/listinfo/asn1 _______________________________________________ ASN1 mailing list [email protected] http://lists.asn1.org/mailman/listinfo/asn1
