Table of Contents

1. Overview
2. Normative references
3. Definitions and syntax
4. Protocol details
5. Compliance
Annex A (informative) - Communication example (Layer 7
        and Layer 2)
Annex B (informative) - Packet transmission example
Annex C (informative) - Service sequence state control
Annex D (informative) - Modifications and extensions to
        ANSI C12.19-1997
Annex E (informative) - CRC examples
Annex F (informative) - Error handling
Annex G (normative) - Data encryption standard (DES)
Annex H (informative) - I command operational description
Annex I (informative) - Compatibility
Annex J (normative) - Listing of editorial errors and
        errors of omission in ANSI C12.21-2006

Abstract

Specifies the criteria required for communication between a C12.21 Device and a C12.21 Client via a modem connected to the switched telephone network.

General Product Information

Published
Document Type	Standard
Status	Current
Publisher	Institute of Electrical & Electronics Engineers
Pages
ISBN