Internet DRAFT - draft-hss-megaco-r1package
draft-hss-megaco-r1package
Internet Engineering Task Force V.Bajaj
Internet Draft K.Laha
Document: draft-hss-megaco-r1package-00.txt Hughes Software Systems
April 11, 2000
Expires october 11, 2000
Megaco/H.248 R1 Package
Status of this document
This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of RFC2026 [ ].
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1. Abstract
This document is work in progress and defines the MF package 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 [ ].
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. Document Organization
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Internet Draft Megaco/H.248 R1 Package April 11, 2000
The subsequent portion of this draft is organized into the following
major sections:
* Introduction to R1 signaling
* Assumptions
* Description of the R1 package
* References
* Author's Address
4. Introduction to R1 signaling
Signaling System R1 [ ] may be applied for automatic and semi-automatic
operation of one-way or both-way circuits, within an international region.
It employs both line and register signaling to convey supervisory and
address signals respectively.
Signaling System R1 transmits supervisory signals, link-by-link, using a
single frequency in-band continuous tone for analogue working. The
presence or absence of this frequency on the line indicates a specific
signal. The line signaling on PCM systems is channel associated.
The register signaling uses link-by-link multi-frequency (MF) in-band
pulse signaling for the transmission of address signals. The address
signals follow a 2-out-of-6 frequency combination preceded by a
start-of-pulsing indication (KP) and terminated by an end-of-pulsing
indication (ST).
5. Assumptions
The following draft assumes the support of ITU-T compliant [4] R1
signaling only.
R1 defines a "delay-dialing" backward line signal to acknowledge the
"seizing" forward signal and delay the attachment of registers at the
outgoing end till registers are attached at the incoming end for
collecting address signals. When registers are attached at the incoming
end and it is ready to receive address signals, the incoming end sends
the "start-dialing"/"proceed-to-send" signal to the outgoing end. The
"start-dialing" signal is simply an indication to start out-pulsing the
address signals and it is sufficient that the interpretation of this
signal remains confined to MG and is not needed to be routed to MGC as
an event. Hence the event reporting "delay-dialing" to MGC is equivalent
to an acknowledgement to the signal that generates "seizing" signal on
the trunk.
The KP and ST signals which form the pre-amble and post-amble of the
inter-register signaling, can also be confined to MG which it attaches
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or strips on its own without the MGC bothering about the same. The MGC
only sends the digit information and collects the same from MG.
6. R1 Package Description
6.1 Package
Package Name: R1 Package
Package ID: r1 (To be allocated through IANA)
Description: This package is used to handle signals and events on
terminations supporting Signaling System R1 between the Media
Gateway and the PSTN network.
Version: 1
Extends: None
6.2 Properties
None defined by this package
6.3 Events
6.3.1
Event Name: Seizure
EventID: sz (0x0001)
Description: The Seizure event shall be reported when an incoming R1
"Seizing" signal occurs on the termination and an events descriptor
is activated that requests the Seizure event. The line signal
condition against which the "Seizing" signal is verified is
provisioned in the MG.
EventsDescriptor Parameters:
Parameter Name: Seize signal validation time
Parameter id: sztim (0x0001)
Description: specifies the minimum duration for which the "Seizing"
signal must persist for the same to be reported as an event.
Gateway shall have default value for this timer.
Type: integer, in milliseconds
Possible values: 0 and up
ObservedEventsDescriptor Parameters:
none defined by this package
6.3.2
Event Name: Seizure Acknowledge
EventID: sa (0x0002)
Description: The Seizure Acknowledge event shall be reported when an
incoming R1 line signal "delay-dialing" occurs on the termination
in response to an outgoing "Seizing" signal already sent and an
events descriptor is activated that requests the Seizure Acknowledge
event. The line signal condition against which the "delay-dialing"
signal is verified is provisioned in the MG.
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EventsDescriptor Parameters:
none defined by 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 R1
line signal "Answer" occurs on the termination and an events
descriptor is activated that requests the Answer event. The line
signal condition against which the "Answer" signal is verified is
provisioned in the MG.
EventsDescriptor Parameters:
none defined by this package
ObservedEventsDescriptor Parameters:
none defined by this package
6.3.4
Event Name: Clear
EventID: clr (0x0004)
Description: The Clear event shall be reported when an incoming R1
line signal "Clear-forward" or "Clear-back" occurs on the
termination and the an events descriptor is activated that requests
the Clear event. Whether "Disconnect" or "Hang-up" shall depend on
the end initiating the call clearing. The line condition against
which either of the signals is verified is provisioned in the MG.
EventsDescriptor Parameters:
Parameter Name: Clear-forward signal validation time
Parameter id: clftim (0x0001)
Description: specifies the minimum duration for which the Gateway
if behaving as an incoming end, validates the "clear-forward"
signal before declaring it as a Clear event reportable to MGC.
This validation time differs depending on whether registers have
been attached or not. Gateway shall have default value for this
timer.
Type: integer, in milliseconds
Possible values: 0 and up
ObservedEventsDescriptor Parameters:
none defined by this package
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6.3.5
Event Name: Address
EventID: addr (0x0005)
Description: Detects the complete R1 address information as received
through register signaling. The event shall be reported after
collecting the complete address digits and an events descriptor is
activated requesting the Address event. The address digits shall be
collected as per a digitmap. The actual frequency, cadence, duration
and amplitude values against which the multi-frequency tones that
convey the address information are validated are provisioned in the
MG.
EventsDescriptor Parameters:
none defined by this package
ObservedEventsDescriptor Parameters:
Parameter Name: Digit String
ParameterID: ds (0x0001)
Description: The portion of the collected address digits which
matched part or all of an alternative event sequence specified
in the digit map.
Type: string of digits (possibly empty) returned as a quoted string.
Possible Values: a sequence of the characters "0" through "9"
Parameter Name: Termination Method
ParameterID: tm (0x0002)
Description: indicates the reason for the generation of the Address
event.
Type: enumeration
Possible Values:
"UM" (0x0001) Unambiguous Match
"PM" (0x0002) Partial Match, completion by timer expiry or
unmatched event
"FM" (0x0003) Full Match, completion by timer expiry or unmatched
event
6.3.6
Event Name: Failure
EventID: fail (0x0006)
Description: Reports a failure condition in the working of the R1
line or register signaling when an events descriptor is activated
requesting the Failure event.
EventsDescriptor Parameters:
none defined by this package
ObservedEventsDescriptor Parameters:
Parameter Name: Error code
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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
6.4 Signals
6.4.1
Signal Name: Seizure
SignalID: sz (0x0001)
Description: Applies a "Seizing" signal on the R1 termination. The
line signal that is actually sent on the physical termination is
provisioned in the MG.
Signal Type: (OO) on/off
Duration: Not applicable
Additional Parameters: None
6.4.2
Signal Name: Seizure Acknowledge
SignalID: sa (0x0002)
Description: Applies "delay-dialing" in response to "seizing" signal
and "start-dialing" once the registers are ready to receive the
address digits. The line condition that is actually sent on the
physical termination is provisioned in the MG.
Signal Type: (OO) on/off
Duration: Not applicable
Additional Parameters: None
6.4.3
Signal Name: Answer
SignalID: ans (0x0003)
Description: Applies an "Answer" signal on the R2 termination. The
line condition that is actually sent on the physical termination
is provisioned in the MG.
Signal Type: (OO) on/off
Duration: Not applicable
Additional Parameters: None
6.4.4
Signal Name: Clear
SignalID: clr (0x0004)
Description: Applies a "Clear-forward" or a "Clear-back" signal
depending on whether the Gateway represents the outgoing or incoming
side for the call on the concerned physical termination (R1 trunk).
The line condition that is actually sent on the physical termination
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is provisioned in the MG.
Signal Type: (OO) on-off
Duration: Provisioned
6.4.5
Signal Name: Address
SignalID: addr (0x0005)
Description: Applies the address signals in the form of MF-tones on
the R1 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.
Possible Values: a sequence of the characters "0" through "9"
6.5 Statistics
none
6.6 Procedures
None
7. References
8. 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.
mEmail: 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.
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Full Copyright Statement
"Copyright (C) The Internet Society (April,2000). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published and
distributed, in whole or in part, without restriction of any kind,
provided that the above copyright notice and this paragraph are included
on all such copies and derivative works. However, this document itself
may not be modified in any way, such as by removing the copyright notice
or references to the Internet Society or other Internet organizations,
except as needed for the purpose of developing Internet standards in
which case the procedures for copyrights defined in the Internet Standards
process must be followed, or as required to translate it into
1. Bradner, S., "The Internet Standards Process -- Revision 3", BCP 9,
RFC 2026, October 1996.
2. Draft Recommendation H.248 (February 2000), Temporary Document 37
(PLEN), Study Group 16, ITU-Telecommunication Standardization Sector
(to be issued as draft-ietf-megaco-protocol-07.txt)
3. Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels",
BCP 14, RFC 2119, March 1997
4. Specifications of Signaling System R1, Q.310-Q.331, Blue Book, CCITT
