Media Gateway Control Sarah Cornel C. Michael Brown Internet Draft Nortel Networks Document: draft-cornel-megaco-enhancedd-00.txt July 2000 Category: Informational Enhanced DTMF Detection Package for Megaco/H.248 Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026 [1]. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet- Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. 1. Abstract This document provides proposed definitions for a supplemental package for Megaco/H.248. This package addresses enhanced support of DTMF detection. 2. Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC-2119 [2]. 3. Enhanced DTMF Detection Package Definition 3.1 Enhanced DTMF Detection Package PackageID: edd Version: 1 Extends: dd version 1 This packages extends the mechanisms for detecting and reporting DTMF tones. Additionally, it changes the way the digit maps are interpreted. cornel 1 draft-cornel-megaco-enhancedd-00.txt July 2000 The package depends on tones described in packages dg and dd (basic DTMF generator package and DTMF detection package). Properties None. Events DigitMap Matched Completion Event EventID: mce EventsDescriptor parameters: Digit map processing is activated only if a digit map parameter is present, specifying a digit map by name or by value. Other parameters such as a KeepActive flag, embedded Events or Signals Descriptors may be present. ObservedEventsDescriptor parameters: DigitString ParameterID: ds (0x0001) Type: string of digit map symbols (possibly empty) returned as a quotedString. Possible values: a sequence of the characters "0" through "9", "A" through "F", and the long duration modifier "Z". Description: the portion of the current dial string as described in the procedures section which matched all of an alternative event sequence specified in the digit map. Termination Method ParameterID: Meth (0x0003) Type: enumeration Possible values: "UM" (0x0001) Unambiguous match "FM" (0x0003) Full match, completion by timer expiry or unmatched event Description: indicates the reason for generation of the event. See the procedures section. Signals None. Statistics None. Procedures Procedures for detecting this event are different than those for the completion event (dd/ce). Procedures for invoking these procedures apply if the matched completion event is requested. It should be noted that the completion event (dd/ce) and the matched completion event (edd/mce) are incompatible. A request for both these events should treat the completion event (dd/ce) as the event with precedence. Cornel Informational - Expires: January 2001 2 draft-cornel-megaco-enhancedd-00.txt July 2000 The following describes the procedures for the matched digit map completion event.A digit map is active while the events descriptor which invoked it is active and it has not completed. A digit map completes when: an alternative event sequence has been matched and no other alternative event sequence in the digit map could be matched through detection of an additional event (unambiguous match), or an event has been detected (usually another digit or timer expiry) such that a match to a complete alternative event sequence of the digit map will be impossible no matter what additional events are received, and at least one event sequence is matched (full match). Upon completion, a digit map completion event as defined in this package providing the events being mapped into the digit map shall be generated. At that point the digit map is deactivated, however collection of events into the _event buffer_ continues until explicitly stopped. Alternatively, one of the following conditions may be detected: an event has been detected such that a match to a complete alternative event sequence of the digit map will be impossible no matter what additional events are received, and no event sequence is matched, or a timer has expired and no sequence is matched. If these conditions occur, the contents of the current dial string should have the first event in its buffer flushed, and the current digit map should be reapplied. These are considered to be reset conditions for the digit map. This process continues until either there is a match, or the request is terminated. Additionally, unless noted here, the processing of the current dial string and the digit map proceeds like the processing of a completion event (dd/ce) . 4. Formal Syntax Not Applicable The following syntax specification uses the augmented Backus-Naur Form (BNF) as described in RFC-2234 [3]. 5. Security Considerations Not Applicable 6. References Cornel Informational - Expires: January 2001 3 draft-cornel-megaco-enhancedd-00.txt July 2000 1 Bradner, S., "The Internet Standards Process -- Revision 3", BCP 9, RFC 2026, October 1996. 2 Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997 3 Crocker, D. and Overell, P.(Editors), "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, Internet Mail Consortium and Demon Internet Ltd., November 1997 7. Acknowledgments 8. Author's Addresses Sarah Cornel Nortel Networks 4008 Chapel Hill Road Research Triangle Park, NC USA 27709 Phone: (919) 991-2853 Email: sarahc@nortelnetworks.com C. Michael Brown Nortel Networks 4008 Chapel Hill Road Research Triangle Park, NC USA 27709 Phone: (919) 991-7767 Email: C.Michael.Brown@nortelnetworks.com 9. 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The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF Cornel Informational - Expires: January 2001 4 draft-cornel-megaco-enhancedd-00.txt July 2000 THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE." 10. Expiration Date This memo is filed as draft-cornel-megaco-enhancedd-00.txt, and expires January 2001. Cornel Informational - Expires: January 2001 5