INTRODUCTION

ASN1VE (ASN.1 Viewer / Editor) is a graphical user interface (GUI) tool for analyzing ASN.1 encoded data. It provides the capability to assign an ASN.1 schema to binary data to produce multiple views of the data showing all of the assigned type and element names.

Examples of some of the message types that can be viewed, created, or edited are:

• PER 3G and 4G ASN.1-based signaling protocol messages such as those used in the NBAP, RANAP, RNSAP, RRC, S1AP, and X2AP protocols.
• OMA Secure User Plane Location (SUPL) messages which are used in many GPS related applications.
• H.323 protocol signalling messages.
• X.509 certificates (*.cer,*.crt)
• Transferred Account Procedure (TAP3) batch files
• Files containing Call Detail Records (CDR's) in various vendor formats

The basic functionality contained within ASN1VE may be used free without a license. It includes viewing the basic structure of BER-encoded data in tree, hex, and detail views. Advanced functionality requires a license file be purchased. Advanced features include the following:

• Ability to associate an ASN.1 definition with a binary message
• Ability to edit data fields within a message.
• XML and brace text views of the ASN.1 message structure
• Search command to find various items in decoded messages
• Ability to input binary message data as Hexadecimal text
• Ability to create and edit Packed Encoding Rules (PER) messages.

ASN1VE will display a BER or DER encoded message in two different views:

• Tag View: This view will display a message in a generic form showing tags, lengths, and data. This is the default view when a message file is first opened. It is also the only view shown if no ASN.1 schema is assigned to describe the message.
• Element View: This view will display the structure of a message using type and element names from an assigned ASN.1 schema definition. The schema is assigned using the 'Assign ASN.1' or 'Assign ASN.1 Wizard' commands. This view will also allow editing of the encoded fields of a BER message. For PER, this is the only view supported since the structure of a PER message cannot be determined without schema information.