Internet Engineering Task Force V.Bajaj K.Laha Internet Draft Hughes Software Systems Document: draft-manyfolks-megaco-caspackage-02 Bill Foster Category: Standards Track Cisco Systems Kevin Boyle II Wendy Bothwell Nortel Networks Michael Brown March 2002 Megaco/H.248 Basic CAS Packages Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026 [2]. 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 defines Basic Channel Associated Signalling (CAS) and R1 packages and supplemental CAS packages in association with the Megaco/H.248 Protocol that can be used to control a Media Gateway (MG) from an external controller, called a Media Gateway controller (MGC). It is intended to satisfy the requirements in section 12 of the Megaco/H.248 requirement document [1]. 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 [3]. 3. Document Organization The subsequent portion of this draft is organized into the following major sections: Manyfolks Standards Track -- Expires Sept. 2002 1 Megaco/H.248 Basic CAS Package Mar 2002 * Introduction * Assumptions and Partitioning * Description of the Basic CAS package * Description of the Robbed Bit Signalling package * Description of the Operator Services and Emergency Services package * Description of the Operator Services Extension package * References * Author's Addresses * Appendix showing call flows 4. Introduction The Basic CAS (Channel Associated Signalling) Package provides a baseline package. Basic CAS defines abstract events and signals that are common to all CAS protocols. For some protocols, Basic CAS provides all of the functionality required to satisfy the interface, such as North American single-stage dialing applications or R1 signalling. For other protocols, Basic CAS provides a baseline package for which additional protocol specific extension packages can be defined. Further line signals and events required for international signaling protocols can be provided through extension packages. The RBS (Robbed Bit Signalling) Package, Operator Services and Emergency Services Package and the Operator Services Extension Package can be used to provide functionality required in addition to the Basic CAS Package. 5. Assumptions and Partitioning The termination the MGC addresses is the channel. With TS16, the MG associates the line signal with the appropriate channel. For some applications, the Basic CAS package provides all of the functionality needed to satisfy the interface. In other cases (e.g. operator services), additional supplementary packages may be needed to meet the complete interface requirements. This internet draft includes three supplementary packages which may be used to provide additional functionality required by some interfaces: The Robbed Bit Signalling package provides basic RBS supervisory signalling that is required in addition to the Basic CAS package. The Operator Services and Emergency Services package provides supervisory signalling that is specific to North American Operator Services and Emergency Services. The Operator Services Extension package provides supervisory signalling that is specific to North American Operator Services and Manyfolks Standards Track -- Expires Sept. 2002 2 Megaco/H.248 Basic CAS Package Mar 2002 is required in addition to the Operator Services and Emergency Services package. 6. Basic CAS Package Description 6.1 Package Package Name: Basic CAS Package Package ID: bcas (0x003f) Description: This package provides basic event and signal handling for terminations that support CAS Signalling. Version: 1 Extends: None 6.2 Properties The MG has a provisioned value for each of the following properties. The MG uses the provisioned value by default. Depending on the CAS signalling protocols, it may be necessary for the MGC to change these values for a call. Property Name: seize signal validation time PropertyID: sztim (0x0001) Description: Specifies the minimum duration for which the "seizing" signal must persist for the same to be reported as an event. Type: integer Possible Values: 0 and up in milliseconds Defined In: TerminationState Characteristics: Read/Write Property Name: start dialing timeout PropertyID: sdto (0x0002) Description: Specifies the timer for the receipt of the "start dialing" signal. A value of 0 indicates a timer should not be applied. Type: integer Possible Values: 0 and up in milliseconds. Defined In: TerminationState Characteristics: Read/Write Property Name: answer signal validation time PropertyID: anstim (0x0004) Description: Specifies the minimum duration for which the "answer" signal must persist for the same to be reported as an event. Type: integer Possible Values: 0 and up in milliseconds Defined In: TerminationState Characteristics: Read/Write Property Name: clear signal validation time PropertyID: clrtim (0x0005) Manyfolks Standards Track -- Expires Sept. 2002 3 Megaco/H.248 Basic CAS Package Mar 2002 Description: Specifies the minimum duration for which the gateway, if behaving as an incoming end, validates the "clear-forward" signal (or on-hook). Type: integer Possible Values: 0 and up in milliseconds Defined In: TerminationState Characteristics: Read/Write 6.3 Events 6.3.1 Event Name: Seizure EventID: sz (0x0001) Description: The Seizure event shall be reported when an incoming "Seizing" signal occurs on the termination. The event is reported by the MG if either the timed transition to this line signal is detected or the line signal already exists. The line signal condition against which the "Seizing" signal is verified is provisioned in the MG. EventsDescriptor Parameters: none defined for this package ObservedEventsDescriptor Parameters: none defined by this package 6.3.2 Event Name: Start Dialing EventID: sd (0x0002) Description: The "Start Dialing" event indicates that out-pulsing should begin. For R1 interfaces, the event is reported when the "start dialing"/"proceed to send" signal occurs. For wink start trunks, the "Start Dialing" event is reported when the trailing edge of the wink-start signal occurs. For immediate start trunks, the "Start Dialing" event is provided by the media gateway as an immediate response to the request for that event from the MGC. EventsDescriptor Parameters: none defined for this package ObservedEventsDescriptor Parameters: none defined by this package 6.3.3 Event Name: Answer EventID: ans (0x0003) Description: The Answer event shall be reported when an incoming line signal "Answer" occurs on the termination. The event is reported by the MG if either the timed transition to this line signal is detected or the line signal already exists. The line signal condition against which the "Answer" signal is verified is provisioned in the MG. EventsDescriptor Parameters: none defined for this package Manyfolks Standards Track -- Expires Sept. 2002 4 Megaco/H.248 Basic CAS Package Mar 2002 ObservedEventsDescriptor Parameters: none defined by this package 6.3.4 Event Name: Clear Forward EventID: cf (0x0004) Description: This event applies to an incoming interface and is reported when a "Clear" line signal occurs on the termination. For an R1 interface, the Clear Forward event shall be reported when a "Clear-forward" line signal occurs on the termination. For robbed bit signalling digital interfaces, it corresponds to an "on-hook" indication on the termination. The event is reported by the MG if either the timed transition to this line signal is detected or the line signal already exists. The condition against which the signal is verified is provisioned in the MG. The parameter "clear guard timing" can optionally be included. EventsDescriptor Parameters: Parameter Name: Clear Guard Timing ParameterID: clgdt (0x0001) Description: Specifies whether the MG shall start a clear guard timer for the receipt of the "clear forward" signal. If the clear guard timer expires prior to the detection of clear forward signal and the CAS Failure event is active, the MG shall report a CAS Failure event with a "clto" error code. The timer value is provisioned on the MG. If the clgdt parameter is not provided, the MG does not perform timing by default. Type: boolean Possible values: True when the clear guard timing is requested and false when the clear guard timing is turned off. ObservedEventsDescriptor Parameters: none defined by this package 6.3.5 Event Name: Clear Back EventID: cb (0x0005) Description: This event applies to an outgoing interface and is reported when a "Clear" line signal occurs on the termination. For an R1 interface, the Clear Back event shall be reported when a "Clear-back" line signal occurs on the termination. For robbed bit signalling digital interfaces, it corresponds to an "on-hook" indication on the termination. The event is reported by the MG if either the timed transition to this line signal is detected or the line signal already exists. The condition against which the signal is verified is provisioned in the MG. The parameter "clear guard timing" can optionally be included. EventsDescriptor Parameters: Parameter Name: Clear Guard Timing ParameterID: clgdt (0x0001) Manyfolks Standards Track -- Expires Sept. 2002 5 Megaco/H.248 Basic CAS Package Mar 2002 Description: Specifies whether the MG shall start a clear guard timer for the receipt of the "clear back" signal. If the clear guard timer expires prior to the detection of clear back signal and the CAS Failure event is active, the MG shall report a CAS Failure event with a "clto" error code. The timer value is provisioned on the MG. If the clgdt parameter is not provided, the MG does not perform timing by default. Type: boolean Possible values: True when the clear guard timing is requested and false when the clear guard timing is turned off. ObservedEventsDescriptor Parameters: none defined by this package 6.3.6 Event Name: CAS Failure EventID: casf (0x0006) Description: Reports general CAS failures associated with this package. EventsDescriptor Parameters: none defined for this package ObservedEventsDescriptor Parameters: none defined by this package Parameter Name: Error code ParameterID: ec (0x0001) Description: describes the failure reason Type: enumeration Possible Values: "ULS" (0x0001) Unexpected line signal "LTO" (0x0002) Line signal timeout "RTO" (0x0003) Register signal timeout "SME" (0x0004) Protocol State machine malfunction "SDO" (0x0005) Start Dialing Timeout "ANO" (0x0006) Answer Timeout "ADR" (0x0007) Error during outpulsing "CLTO" (0x0008) Clear Guard Timeout 6.4 Signals 6.4.1 Signal Name: Seizure SignalID: sz (0x0001) Description: Applies a "Seizing" signal on the termination. The signal that is actually sent on the physical termination is provisioned in the MG. The Seizure signal is not terminated by the MG when an event is detected. Signal Type: (BR) Brief Duration: Not applicable Additional Parameters: None Manyfolks Standards Track -- Expires Sept. 2002 6 Megaco/H.248 Basic CAS Package Mar 2002 6.4.2 Signal Name: Answer SignalID: ans (0x0002) Description: Applies an "Answer" signal on the termination. The signal that is actually sent on the physical termination is provisioned in the MG. The Answer signal is not terminated by the MG when an event is detected. Signal Type: (BR) Brief Duration: Not applicable Additional Parameters: None 6.4.3 Signal Name: Clear Forward SignalID: cf (0x0003) Description: This signal applies to an outgoing interface and is used to clear a call in the forward direction. The signal type that is actually sent on the physical termination is provisioned in the MG. The Clear Forward signal is not terminated by the MG when an event is detected. Signal Type: (BR) Brief Duration: Not applicable Additional Parameters: None 6.4.4 Signal Name: Clear Back SignalID: cb (0x0004) Description: This signal applies to an incoming interface and is used to clear a call in the backward direction. The signal type that is actually sent on the physical termination is provisioned in the MG. The Clear Back signal is not terminated by the MG when an event is detected. Signal Type: (BR) Brief Duration: Not applicable Additional Parameters: None 6.4.5 Signal Name: Address SignalID: addr (0x0005) Description: Applies the address signals in the form of either DTMF, dial-pulse or MF-tones on the trunk. The actual frequency, cadence, duration and amplitude values for the multi- frequency tones that convey the address information are provisioned in the MG. Signal Type: (BR) Brief Duration: Provisioned Additional Parameters: Parameter Name: Digit String ParameterID: ds (0x0001) Description: The digit string that needs to be sent as address signals. Type: string of digits. Manyfolks Standards Track -- Expires Sept. 2002 7 Megaco/H.248 Basic CAS Package Mar 2002 Possible Values: a sequence of the characters "0" through "9" as well as "A" through "H" ("A" through "H" used for MF signalling - refer to the symbols defined for the digit map in the MF Tone Detection package). Parameter Name: Address Delay ParameterID: ad (0x0002) Description: Specifies a timed delay that is applied prior to signalling the address. The address delay is optional. If the address delay parameter is not provided, the MG uses the provisioned value by default. Type: integer Possible Values: 0 and up in milliseconds Parameter Name: Address Coding ParameterID: ac (0x0003) Description: Specifies the coding of Digit String parameter in tones or DC pulses. Address Coding is optional; if not provided, the MG uses the value provisioned as an attribute of the circuit associated with the signal. Type: enumeration Possible Values: "DTMF" (0x0000) DTMF Digits "MF" (0x0001) MF Digits "DP" (0x0002) Dial Pulse Digits 6.5 Statistics none 6.6 Procedures 6.6.1 Glare Procedures Gateways shall have a configurable glare information element on a per-DS0 basis that can be set to indicate whether the gateway is the controlling or non-controlling "switch". In the case of PBX interconnect, PBXs are either pre-configured or can be configured to behave as non-controlling switches. In this case if they see an off-hook that exceeds the allowable wink length, they will attach a receiver, go on-hook, and await digits for a new call. The PBX will in addition retry its original call on another trunk. In the case where the DS0 is configured for the non-controlling switch, the gateway will indicate a glare occurrence by reporting a seizure event to the MGC. Upon receipt of the seizure event, the MGC begins procedures to release the outgoing call attempt and begins procedures to process the incoming call attempt. If the gateway is a controlling switch, when glare is detected, the gateway will wait for a timeout value (default value of 4 seconds) until the incoming off-hook changes to an on-hook state at which time it will start out-pulsing in the normal manner. If the timeout occurs before the state change to on-hook occurs, the far end has Manyfolks Standards Track -- Expires Sept. 2002 8 Megaco/H.248 Basic CAS Package Mar 2002 refused to back down. This may occur if both ends of the interface are provisioned as the controlling switch. In this case, when the timeout occurs, the gateway reports the seizure event to the MGC. The MGC, upon receipt of the notify with seizure event, begins procedures to back down on the outgoing call attempt and begins procedures to process the incoming call attempt. It is possible for internal glare to occur between the MGC and the gateway. With internal glare, the gateway detects a seizure event on the DS0, signals a start dial and reports the seizure event to the MGC. At the same time the gateway reports the seizure event to the MGC, the MGC sends a request to the gateway to signal a seizure on the DS0. In this case, the start dial has already been signaled by the gateway in response to the incoming seizure. Therefore the MGC must back down on the outgoing call attempt. The gateway, upon receipt of the modify request to signal a seizure, recognizes internal glare has occurred and takes no action on the modify request. The MGC, upon receipt of the notify with seizure event, recognizes internal glare has occurred and begins procedures to back down on the outgoing call attempt and begins procedures to process the incoming call attempt. 6.6.2 Timestamp Procedures Inclusion of a timestamp in the ObservedEvents descriptor is mandatory for the basic CAS package. The timestamp reflects the detection time for the event and may be used by services (e.g. automatic message accounting) on the MGC. 6.6.3 Signal Procedures The Seizure, Answer, Clear Forward and Clear Back signals shall not be terminated by the MG when an event is detected. If one of these signals is active when the MG detects an event, the MG shall keep the signal active and report the event. 6.6.4 Error Handling A line signal should always be present on a CAS interface. If the MGC sets a SignalsDescriptor that would result in the removal of a line signal without the specification of a new line signal, such as an empty SignalsDescriptor, the execution of the command fails. The MG SHALL include error code 458 "Illegal action, line signal can not be stopped" in its response. 6.7 Error Code This package defines a new error code: 458 - Illegal action, line signal can not be stopped The procedure for use with this error code is given in section 6.6.4. 7. Robbed Bit Signalling Package 7.1 Package Manyfolks Standards Track -- Expires Sept. 2002 9 Megaco/H.248 Basic CAS Package Mar 2002 PackageID: rbs (0x0040) Description: This package defines events and signals that are specific to robbed bit signalling and are required in addition to the base CAS functionality provided by the bcas package. Version: 1 Extends: None 7.2 Properties The MG has a provisioned value for each of the following properties. The MG uses the provisioned value by default. Depending on the CAS signalling protocols, it may be necessary for the MGC to change these values for a call. Property Name: Pulse Generation Duration PropertyID: psgen (0x0001) Description: Specifies the duration for a pulse signal. Type: integer Possible Values: 0 and up in milliseconds Defined In: TerminationState Characteristics: Read/Write Property Name: Minimum Pulse Detection Duration PropertyID: minpsdet (0x0002) Description: Specifies the minimum duration for detecting a pulse. Type: integer Possible Values: 0 and up in milliseconds Defined In: TerminationState Characteristics: Read/Write Property Name: Maximum Pulse Detection Duration PropertyID: maxpsdet Description: Specifies the maximum duration for detecting a pulse. Type: integer Possible Values: 0 and up in milliseconds Defined In: TerminationState Characteristics: Read/Write 7.3 Events 7.3.1 Event Name: Pulse Off EventID: psoff (0x0001) Description: The MG detects and reports a timed transition from on- hook to off-hook (leading edge) to on-hook (trailing edge). The parameter "pulse timeout" can be optionally included to specify a timeout for the receipt of the pulse. The default value for the timer is provisioned in the MG. The minimum and maximum duration of the pulse are defined by the Minimum Manyfolks Standards Track -- Expires Sept. 2002 10 Megaco/H.248 Basic CAS Package Mar 2002 Pulse Detection Duration and Maximum Pulse Detection Duration properties respectively. EventsDescriptor Parameters: Parameter Name: Pulse Timeout ParameterID: psto (0x0001) Description: Specifies the timer for the receipt of the pulse. A value of 0 indicates a timer should not be applied. Type: integer Possible values: 0 and up in milliseconds ObservedEventsDescriptor Parameters: None 7.3.2 Event Name: Pulse On EventID: pson (0x0002) Description: The MG detects and reports a timed transition from off- hook to on-hook (leading edge) to off-hook (trailing edge). The parameter "pulse timeout" can be optionally included to specify a timeout for the receipt of the pulse. The default value for the timer is provisioned in the MG. The minimum and maximum duration of the pulse are defined by the Minimum Pulse Detection Duration and Maximum Pulse Detection Duration properties respectively. EventsDescriptor Parameters: Parameter Name: Pulse Timeout ParameterID: psto (0x0001) Description: Specifies the timer for the receipt of the pulse. A value of 0 indicates a timer should not be applied. Type: integer Possible values: 0 and up in milliseconds ObservedEventsDescriptor Parameters: None 7.3.3 Event Name: RBS Failure EventID: rbsfail (0x0003) Description: Reports a failure condition when an rbs failure occurs. EventsDescriptor Parameters: None. ObservedEventsDescriptor Parameters: Parameter Name: Error Code ParameterID: ec (0x0001) Description: Describes the failure reason Type: enumeration Possible Values: "psto" (0x0001) Timeout waiting for a pulse event 7.4 Signals 7.4.1 Signal Name: Pulse Off-hook SignalID: psoff (0x0001) Description: The MG signals a timed transition from on-hook to off- hook (leading edge) to on-hook (trailing edge). Signal Type: Brief Manyfolks Standards Track -- Expires Sept. 2002 11 Megaco/H.248 Basic CAS Package Mar 2002 Duration: Defined by Pulse Generation Duration property. Additional Parameters: None 7.4.2 Signal Name: Pulse On-hook SignalID: pson (0x0002) Description: The MG signals a timed transition from off-hook to on- hook (leading edge) to off-hook (trailing edge). Signal Type: Brief Duration: Defined by Pulse Generation Duration property. Additional Parameters: None 7.5 Statistics None. 7.6 Procedures 7.6.1 Timestamp Procedures Inclusion of a timestamp in the ObservedEvents descriptor is mandatory for the RBS package. The timestamp reflects the detection time for the event and may be used by services (e.g. automatic message accounting) on the MGC. 8. Operator Services and Emergency Services Package 8.1 Package PackageID: oses (0x0041) Description: This package defines the CAS events and signals that are required for North American Operator Services and North American Emergency Services Signalling. Version: 1 Extends: None 8.2 Properties None. 8.3 Events 8.3.1 Event Name: Ringback EventID: rgbk (0x0001) Description: The ringback event is reported when a ringback signal is detected. The type of ringback signal and characteristics of the ringback signal are provisioned in the MG. EventsDescriptor Parameters: None ObservedEventsDescriptor Parameters: None Manyfolks Standards Track -- Expires Sept. 2002 12 Megaco/H.248 Basic CAS Package Mar 2002 8.4 Signals 8.4.1 Signal Name: Ringback SignalID: rgbk (0x0001) Description: Applies a ringback signal on the termination. The type of ringback signal and characteristics of the ringback signal are provisioned on the MG. Signal Type: Brief Duration: Provisioned Additional Parameters: None 8.5 Statistics None. 8.6 Procedures None. 9. Operator Services Extension Package 9.1 Package PackageID: osext (0x0042) Description: This package defines the CAS events and signals that are specific to North American Operator Services Signalling and are required in addition to the events and signals defined in the Operator Services and Emergency Services package. Version: 1 Extends: oses (To be allocated through IANA) Version 1 9.2 Properties None. 9.3 Events 9.3.1 Event Name: Recall EventID: rcl (0x0002) Description: The recall event is reported when a recall signal is detected on a termination. The recall signal is a timed transition from off-hook to on-hook (leading edge) to off-hook (trailing edge). The duration of the timed transition is provisioned on the MG. EventsDescriptor Parameters: None Manyfolks Standards Track -- Expires Sept. 2002 13 Megaco/H.248 Basic CAS Package Mar 2002 ObservedEventsDescriptor Parameters: None 9.3.2 Event Name: Coin Collect EventID: cc (0x0003) Description: The coin collect event is reported when a coin collect signal is detected on a termination. The type of coin collect signal and characteristics of the coin collect signal are provisioned on the MG. EventsDescriptor Parameters: None ObservedEventsDescriptor Parameters: None 9.3.3 Event Name: Coin Return EventID: cr (0x0004) Description: The coin return event is reported when a coin return signal is detected on a termination. The type of coin return signal and characteristics of the coin return signal are provisioned on the MG. EventsDescriptor Parameters: None ObservedEventsDescriptor Parameters: None 9.3.4 Event Name: Operator Attached EventID: oa (0x0005) Description: The operator attached event is reported when an operator attached signal is detected on a termination. The type of operator attached signal and characteristics of the operator attached signal are provisioned on the MG. EventsDescriptor Parameters: None ObservedEventsDescriptor Parameters: None 9.3.5 Event Name: Operator Released EventID: or (0x0006) Description: The operator released event is reported when an operator released signal is detected on a termination. The type of operator released signal and characteristics of the operator released signal are provisioned on the MG. EventsDescriptor Parameters: None ObservedEventsDescriptor Parameters: None 9.4 Signals 9.4.1 Signal Name: Recall SignalID: rcl (0x0003) Description: Applies a timed transition from off-hook to on- hook(leading edge) to off-hook (trailing edge). Signal Type: Brief Duration: Provisioned Additional Parameters: None Manyfolks Standards Track -- Expires Sept. 2002 14 Megaco/H.248 Basic CAS Package Mar 2002 9.4.2 Signal Name: Coin Collect SignalID: cc (0x0004) Description: Applies a coin collect signal on the termination. The type of coin collect signal and characteristics of the coin collect signal are provisioned on the MG. Signal Type: Brief Duration: Provisioned Additional Parameters: None 9.4.3 Signal Name: Coin Return SignalID: cr (0x0005) Description: Applies a coin return signal on the termination. The type of coin return signal and characteristics of the coin return signal are provisioned on the MG. Signal Type: Brief Duration: Provisioned Additional Parameters: None 9.4.4 Signal Name: Operator Attached SignalID: oa (0x0006) Description: Applies an operator attached signal on the termination. The type of operator attached signal and characteristics of the operator attached signal are provisioned on the MG. Signal Type: Brief Duration: Provisioned Additional Parameters: None 9.4.5 Signal Name: Operator Released SignalID: or (0x0007) Description: Applies an operator released signal on the termination. The type of operator released signal and characteristics of the operator released signal are provisioned on the MG. Signal Type: Brief Duration: Provisioned Additional Parameters: None 9.5 Statistics None. 9.6 Procedures None. Formal Syntax Not Applicable Security Considerations Manyfolks Standards Track -- Expires Sept. 2002 15 Megaco/H.248 Basic CAS Package Mar 2002 Security considerations are addressed as per Section 10 of RFC-3015 [2]. IANA Considerations The packages defined in this document are registered as per Section 13, _IANA Considerations_, of RFC 3015 [2]. 10. References Normative 1 Cuervo, et al., "Megaco Protocol Version 1.0", RFC 3015, November 2000. Informative 2 Bradner, S., "The Internet Standards Process -- Revision 3", BCP 9, RFC 2026, October 1996. 3 Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997 14. Author's Addresses Vikas Bajaj Hughes Software Systems, Ltd. Gurgaon, Haryana, India. 122015. Ph: (91)-11-6346666.Ex-2804. Fax: (91)-124-6342810 or 811. Email: vbajaj@hss.hns.com. Kushanava Laha Hughes Software Systems, Ltd. Gurgaon, Haryana, India. 122015. Ph: (91)-11-6346666.Ex-3083 Email: klaha@hss.hns.com. Bill Foster Cisco Systems 170 West Tasman Dr San Jose, CA 95134 Ph: (408) 527-8791 Email: bfoster@cisco.com Wendy Bothwell Nortel Networks Manyfolks Standards Track -- Expires Sept. 2002 16 Megaco/H.248 Basic CAS Package Mar 2002 4008 Chapel Hill Road Research Triangle Park, NC USA 27709 Phone: (919) 991-7287 Email: Bothwell@nortelnetworks.com Kevin Boyle Nortel Networks 4008 Chapel Hill Road Research Triangle Park, NC USA 27709 Phone: (919) 991-2690 Email: Kboyle@nortelnetworks.com C. Michael Brown 1104 Hemingway Drive Raleigh, NC USA 27609 Email: cmbrown@mindspring.com Manyfolks Standards Track -- Expires Sept. 2002 17 Megaco/H.248 Basic CAS Package Mar 2002 15. Appendix A Call Flows 15.1 Basic Single-Stage MF or DTMF wink start or immediate start. Origination: PSTN/PBX MG MGC <-- request to be notified seizure, digits (digit map referenced) --seize-> ---- "bcas/sz"--> <-- seize ack and start dialing --digits--> ---- "mfd/ce" --> digits available later when the other end answers: <--off-hook-- <-- "bcas/ans" --- Termination: MGC MG PSTN/PBX Start with embedded request to do "sz" and if start dialing ("sd") occurs - automatically outpulse address: ---embedded request--> --- Seizure ---> <---- "bcas/sd"------- <-- wink/delay dial followed by proceed to send the MG as a reflex action to doing a seizure with request for "sd" --- digits ---> Note: digits outpulsed automatically because of the embedded request 15.2 EAOSS Termination - Telephone Company Operator Services Call : The following call flow also applies to operator services signalling interfaces defined prior to Exchange Access Operator Services Signalling (EAOSS). MGC MG PSTN Start with a request to seize and report the start dialing event. Option - can use an embedded request for the first set of address digits. ---- request -----> ----seizure---> <----"bcas/sd"----- <----wink----- Manyfolks Standards Track -- Expires Sept. 2002 18 Megaco/H.248 Basic CAS Package Mar 2002 Send a request to signal the first stage of digits (i.e. called) and look for an answer. Signal Completion event can be (optionally) used to indicate when outpulsing is complete. A timeout is specified for the ansto property. -- signal addr1 --> -----addr1----> <------"g/sc"------ <----"bcas/ans"---- <-- off-hook-- Send a request to signal the second stage of digits (i.e. ANI). Signal Completion event is used to indicate when outpulsing is complete. -- signal addr2 --> -----addr2----> <------"g/sc"------ 15.3 EAOSS Termination - IC/INC Operator Services Call indirect through an Access Tandem (Overlap Outpulsing): The following call flow also applies to Feature Group D (FGD) signalling with the exception of an acknowledgment wink in place of the off-hook hold request. MGC MG PSTN Start with a request to seize and report the start dialing event. Option - can use an embedded request for the first set of address digits. ---- request -----> ----seizure---> <----"bcas/sd"----- <----wink----- Send a request to signal the first stage of digits and look for a wink (i.e. a pulse). The first stage of digits consists of KP0ZZXXXXST/STP (national) or KP1N'XXXXXCCCST/STP (international). -- signal addr1 --> -----addr1----> <---"rbs/psoff"---- <-- wink ---- Send a request to signal the second stage of digits (i.e. ANI). Signal Completion event is used to indicate when outpulsing is complete, which supports overlap outpulsing. -- signal addr2 --> -----addr2----> <------"g/sc"------ Send a request to signal the third stage of digits (i.e. called) and look for an acknowledgment wink or an off-hook request for hold. -- signal addr3 --> -----addr3----> <----"rbs/psoff"--- <--- wink ---- OR <----"bcas/ans"---- <---off-hook--- Timeouts for the receipt of the winks are specified using parameter psto. The minimum and maximum durations of the winks are specified using the minpsdet and maxpsdet properties. Manyfolks Standards Track -- Expires Sept. 2002 19 Megaco/H.248 Basic CAS Package Mar 2002 15.4 EAOSS Termination - IC/INC Operator Services Call indirect through an Access Tandem (No Overlap Outpulsing): This call flow is an optimization of the previous call flow when overlap outpulsing is not required. MGC MG PSTN Start with a request to seize and report the start dialing event. This call flow includes an embedded request to signal the first set of address digits (i.e. KP0ZZXXXXST/STP for national or KP1N'XXXXXCCCST/STP for international) and report an event of wink (i.e. a pulse). ---- request -----> ----seizure---> <------"sd"-------- <----wink------ -----addr1----> <----"rbs/psoff"--- <-- wink ---- Send a request that includes a signal list for the second (i.e. ANI)and third (i.e. called) stages of digits. Additionally, look for the acknowledgment wink or off-hook hold request. - signal addr2/3 -> -----addr2----> -----addr3----> <----"rbs/psoff"--- <--- wink ---- OR <----"bcas/ans"---- <---off-hook--- Timeouts for the receipt of the winks are specified using parameter psto. The minimum and maximum durations of the winks are specified using the minpsdet and maxpsdet properties. 15.5 EAOSS Termination - IC/INC "National" Operator direct to the IC/INC (Overlap Outpulsing): MGC MG PSTN Start with a request to seize and report the start dialing event. Option - can use an embedded request for the first set of address digits. ---- request -----> ----seizure---> <---"bcas/sd"------ <----wink----- Send a request to signal the first stage of digits (i.e. ANI). Signal Completion event is used to indicate when outpulsing is complete, which supports overlap outpulsing. -- signal addr1 --> -----addr1----> <------"g/sc"------ Send a request to signal the second stage of digits (i.e. called) and look for the acknowledgment wink or an offhook request for hold. -- signal addr2 --> ----seizure---> <--"rbs/psoff"----- <--- wink ---- OR ----"bcas/ans"------ <---off-hook--- Manyfolks Standards Track -- Expires Sept. 2002 20 Megaco/H.248 Basic CAS Package Mar 2002 The timeouts for the receipt of the wink is specified using parameter psto. The minimum and maximum duration of the wink is specified using the minpsdet and maxpsdet properties. 15.6 EAOSS Termination - IC/INC "National" Operator direct to the IC/INC (No Overlap Outpulsing): This call flow is an optimization of the previous call flow when overlap outpulsing is not required. MGC MG PSTN Start with a request to seize and report the start dialing event. Include an embedded request with a signal list and look for an event of wink or offhook. ---- request -----> ----seizure---> <---"bcas/sd"------ <----wink----- -----addr1----> -----addr2----> <---"rbs/psoff"---- <--- wink ---- OR <----"bcas/ans"---- <---off-hook--- The timeout for the receipt of the wink is specified using parameter psto. The minimum and maximum duration of the wink is specified using the minpsdet and maxpsdet properties. 15.7 EAOSS Origination - Telephone Operating Company serves the call: In this call flow, the MGC is the Telephone Operating Company switch that is providing operator services. The call originates from a PSTN EO and terminates to the MGC for operator handling. Following operator handling, the call completes to the packet network (not shown). PSTN MG MGC Start with a request to be notified of seizure and report digits (digit map referenced). <---- request ---- ------seize-----> ---"bcas/sz"-----> <-----wink------- -----addr1------> -----"mfd/ce"----> Based on the digits received (i.e. KP0ZZXXXXST/STP, KP1N'XXXXXCCCST/STP) and the resulting translation, the MGC determines the call should be served. Send a request to signal a wink and report the next set of digits (i.e. ANI). <-- request --- Manyfolks Standards Track -- Expires Sept. 2002 21 Megaco/H.248 Basic CAS Package Mar 2002 <-----wink------- -----addr2------> -----"mfd/ce"----> Send a request to report the next set of digits and signal an acknowledgment wink or off-hook in place of the acknowledgment wink (i.e. if MGC data indicates hold should be applied for this IC). <---- request ---- -----addr2------> -----"mfd/ce"----> <-----wink------- OR <---off-hook----- Full Copyright Statement "Copyright (C) The Internet Society (April,2000). All Rights Reserved. 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