ETSI TS 183 025 V2.5.1 (2009-04)

Technical Specification
Telecommunications and Internet converged Services and
Protocols for Advanced Networking (TISPAN);
H.248 Non-Call Related Procedures and
Management System Interaction
2 ETSI TS 183 025 V2.5.1 (2009-04)

Reference
RTS/TISPAN-03193-NGN-R2
Keywords
H.248, MGC
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3 ETSI TS 183 025 V2.5.1 (2009-04)
Contents
Intellectual Property Rights . 6
Foreword . 6
1 Scope . 7
1.1 Applicability . 7
1.2 Relation to H.248 Standards . 7
2 References . 8
2.1 Normative references . 8
2.2 Informative references . 8
3 Definitions and abbreviations . 9
3.1 Definitions . 9
3.2 Abbreviations . 10
4 Reference Architecture . 10
5 H.248 Concepts And Logical Entities . 11
5.1 H.248 Entities . 11
5.2 H.248 Non-Call Related Commands . 11
5.3 H.248 Service State . 12
6 Management Primitives . 12
7 Failure/Recovery Scenarios . 12
8 Redundancy Scenarios . 13
9 General Use Cases . 13
10 Interaction Between Use Cases and Non-Call Related H.248 Procedures . 14
10.1 Enable MG . 14
10.1.1 Enable MG (at MGC) . 14
10.1.2 Enable MG (at MG) . 14
10.2 Enable MGC . 16
10.3 Disable MG (Graceful) . 17
10.3.1 Disable MG (Graceful) (at MGC) . 17
10.3.2 Disable MG (Graceful) (at MG) . 18
10.4 Disable MG (Immediate) . 18
10.4.1 Disable MG (Immediate) (at MGC) . 18
10.4.2 Disable MG (Immediate) (at MG) . 19
10.5 Disable MGC . 19
10.6 Enable Termination . 19
10.6.1 Enable Termination (at MGC) . 19
10.6.2 Enable Termination (at MG) . 20
10.7 Disable Termination (Graceful) . 20
10.7.1 Disable Termination (Graceful) (at MGC) . 20
10.7.2 Disable Termination (Graceful) (at MG) . 21
10.8 Disable Termination (Immediate) . 21
10.8.1 Disable Termination (Immediate) (at MGC) . 21
10.8.2 Disable Termination (Immediate) (at MG) . 22
10.9 MG Failure and Recovery . 22
10.10 MG Termination Failure and Recovery . 23
10.11 MGC Failure and Recovery. 23
10.12 User Plane Failure . 23
10.12.1 Failure affecting a Single Termination . 23
10.12.2 Failure affecting Multiple Terminations . 24
10.13 MGC-MG Control Association Failure and Recovery . 24
10.14 MG Overload . 26
10.15 MGC Overload . 27
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4 ETSI TS 183 025 V2.5.1 (2009-04)
10.16 MGC Hand-Off . 27
10.17 MGC Triggered MG Redirect . 28
10.18 MG Failover . 28
10.19 Change of MG Resources . 29
11 Non-Call Related H.248 Procedures and their Contents . 30
11.1 MG Registration (Cold Boot) . 31
11.2 MG Restoration . 32
11.3 Packages Audit . 32
11.4 Context Audit . 33
11.5 MG Termination Available . 35
11.6 MG Termination Unavailable. 36
11.7 Audit Termination State . 37
11.8 Set ROOT Termination Events/Properties . 37
11.9 MGC Initiated Service Restoration . 38
11.10 Check MG Availability . 38
11.11 MG Service Cancellation (Graceful) . 39
11.12 MG Service Cancellation (Immediate) . 39
11.13 MGC Hand-Off . 40
11.14 MG Re-Registration (Handoff) . 41
11.15 MG Termination OOS Graceful . 42
11.16 MGC Overload Notification . 42
11.17 MG Registration Redirect . 43
11.18 User Plane Failure . 44
11.19 Root Event Notification . 44
11.20 MG Lost Communication (Disconnected) . 45
11.21 MG Lost Communication (Failover) . 46
11.22 MG Redundant Takeover (Primary) . 47
11.23 MG Re-Registration (Restart) . 48
11.24 Wildcarded Subtract . 49
11.25 MG Redundant Takeover (Secondary) . 49
11.26 MGC Initiated Service Cancellation. 50
11.27 Void . 50
11.28 Audit ROOT Properties . 50
Annex A (informative): Stage 3 Non-Call Related H.248 Procedures and their Contents . 51
A.1 MG Registration (Cold Boot) . 51
A.2 MG Restoration . 51
A.3 Packages Audit . 52
A.4 Context Audit . 53
A.5 MG Termination Available . 54
A.6 MG Termination Unavailable . 55
A.7 Audit Termination State . 55
A.8 Set ROOT Termination Events/Properties . 56
A.9 MGC Initiated Service Restoration . 56
A.10 Check MG Availability . 57
A.11 MG Service Cancellation (Graceful) . 57
A.12 MG Service Cancellation (Immediate) . 58
A.13 MGC Hand-Off . 58
A.14 MG Re-Registration (Handoff) . 59
A.15 MG termination OOS (Graceful) . 60
A.16 MGC Overload Notification . 60
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5 ETSI TS 183 025 V2.5.1 (2009-04)
A.17 MG Registration Redirect . 61
A.18 User Plane Failure . 61
A.19 Root Event Notification. 62
A.20 MG Lost Communication (Disconnected) . 62
A.21 MG Lost Communication (Failover) . 63
A.22 MG Redundant Takeover (Primary) . 64
A.23 MG Re-Registration (Restart) . 64
A.24 Wildcarded Subtract . 65
A.25 MG Redundant Takeover (Secondary) . 65
A.26 MGC Initiated Service Cancellation . 66
A.27 Void . 66
A.28 Audit ROOT Properties . 66
Annex B (informative): Relation of the H.248 ServiceStates Property Model with
Management Models . 68
B.1 Introduction . 68
B.2 Scope . 68
B.3 Mapping between Models . 68
B.3.1 Example Management Models . 68
B.4 Interaction Aspects . 69
B.4.1 Effect of H.248 Actions on Management Models . 69
B.4.2 Effect of Management Model State Transition on H.248 Model . 69
B.4.2.1 Configuration management . 69
B.4.2.2 Fault management . 70
B.4.3 Effect of failures in H.248 entities on State Transition in Management Model and H.248 Model . 70
Annex C (informative): Change history . 71
History . 72

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6 ETSI TS 183 025 V2.5.1 (2009-04)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://webapp.etsi.org/IPR/home.asp).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Specification (TS) has been produced by ETSI Technical Committee Telecommunications and Internet
converged Services and Protocols for Advanced Networking (TISPAN).
This technical specification was previously published as a Technical Report.
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7 ETSI TS 183 025 V2.5.1 (2009-04)
1 Scope
The purpose of the present document is to define guidelines with regard to the interaction of non-call related H.248
procedures and generic network management use cases and vice versa. More specifically, the interaction between the
following is considered:
• Control procedures at the H.248 interface. These are the procedures between Media Gateway Controllers
(primary and secondary) and their associated Media Gateways (primary, and secondary if available). These
procedures primarily utilize the H.248 ServiceChange and H.248 Audit procedures.
• Management procedures at the management interface(s) of H.248 systems (i.e. both Media Gateway
Controller and Media Gateway) to perform non call related tasks such as configuration management (start-up,
capability change, maintenance locking) and fault management (failure handling).
It is intended that these guidelines are then subsequently used in corresponding H.248 profiles to produce detailed
non-call related procedures. At the current time, the existing set of ETSI H.248 profiles ( [i.1], [i.2], [i.3] and [i.4]) lack
any such detailed procedures.
Specific management systems, architectures and protocols are outside the scope of the present document; only the
general requirements and Use Cases related to the management system shall be discussed.
1.1 Applicability
The present document is applicable to any network element that exhibits a H.248 interface and a management interface
(e.g. SNMP). The intent of the present document is to provide guidelines so as to facilitate a consistent set of behaviour
for non-call related procedures in the related H.248 profile specifications. Due to the general nature of the present
document, it is possible that some of the procedures herein will not be applicable to certain H.248 profiles - it is for a
specific profile itself to define which procedures are mandatory/optional/not applicable.
The present document assumes an IP-based transport for H.248 signalling. The IP transport may be provided by either
UDP or SCTP.
1.2 Relation to H.248 Standards
The present document is considered to be complementary to H.248 standards where there are discrepancies between the
present document and the correspondent ITU-T Recommendation H.248 series Recommendations, the procedures of
these ITU-T Recommendations (in particular ITU-T Recommendation H.248.1 [i.5] and its annex F on ServiceChange),
take precedence over those described in the present document.
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8 ETSI TS 183 025 V2.5.1 (2009-04)
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• Non-specific reference may be made only to a complete document or a part thereof and only in the following
cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the
purposes of the referring document;
- for informative references.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are indispensable for the application of the present document. For dated
references, only the edition cited applies. For non-specific references, the latest edition of the referenced document
(including any amendments) applies.
Not applicable.
2.2 Informative references
The following referenced documents are not essential to the use of the present document but they assist the user with
regard to a particular subject area. For non-specific references, the latest version of the referenced document (including
any amendments) applies.
[i.1] ETSI ES 283 002 (V1.1.1): "Telecommunications and Internet converged Services and Protocols
for Advanced Networking (TISPAN); PSTN/ISDN Emulation Subsystem (PES); NGN Release 1
H.248 Profile for controlling Access and Residential Gateways".
[i.2] ETSI ES 283 024 (V1.1.1): "Telecommunications and Internet converged Services and Protocols
for Advanced Networking (TISPAN); PSTN/ISDN Emulation: H.248 Profile for controlling
Trunking Media Gateways in the PSTN/ISDN Emulation Subsystem (PES); Protocol
specification".
[i.3] ETSI ES 283 018 (V1.1.1): "Telecommunications and Internet converged Services and Protocols
for Advanced Networking (TISPAN); Resource and Admission Control: H.248 Profile for
controlling Border Gateway Functions (BGF) in the Resource and Admission Control Subsystem
(RACS); Protocol specification".
[i.4] ETSI ES 283 031 (V1.1.1): "Telecommunications and Internet converged Services and Protocols
for Advanced Networking (TISPAN); IP Multimedia: H.248 Profile for controlling Multimedia
Resource Function Processors (MRFP) in the IP Multimedia System (IMS); Protocol
specification".
[i.5] ITU-T Recommendation H.248.1 (2005): "Gateway Control Protocol: Version 3".
[i.6] ITU-T Recommendation H.248.10 (2001): "Gateway control protocol: Media Gateway Resource
Congestion Handling package".
[i.7] ITU-T Recommendation H.248.14 (2002): "Gateway control protocol: Inactivity timer package".
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9 ETSI TS 183 025 V2.5.1 (2009-04)
[i.8] ITU-T Recommendation H.248.11 (2002): "Gateway control protocol: Media Gateway Overload
Control package".
[i.9] ETSI ES 283 039-4 (V2.1.1): "Telecommunications and Internet converged Services and Protocols
for Advanced Networking (TISPAN); NGN Overload Control Architecture; Part 4: Adaptative
Control for the MGC".
[i.10] ITU-T Recommendation H.248.40 (2007): "Gateway control protocol: Application Data Inactivity
Detection package".
[i.11] IETF RFC 4268: "Entity State MIB".
[i.12] ITU-T Recommendation X.731: "Information technology - Open Systems Interconnection -
Systems management: State management function".
[i.13] ITU-T Recommendation H.248.8: " Gateway control protocol: Error code and service change
reason description ".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
control association: H.248 Control Association is defined in clause F.2/H.248.1 version 3 [i.5]
H.248 entity: any primary or secondary MGC or MG may be also denoted as H.248 entity
NOTE 1: An H.248 entity relates to a Functional Entity (FE), any implementation of an H.248 entity is mapping the
functional entity on a Physical Entity (PE).
NOTE 2: E.g. a virtual MG (VMG) is a H.248 FE. Multiple VMGs are realized in a single physical MG, which
relates to an H.248 PE.
NOTE 3: Physical entities are sometimes also denoted as "platform" or "processor".
primary Media Gateway (MG): no explicit definition in H.248
NOTE: The primary MG is rather implicitly defined. See mainly ITU-T Recommendation H.248.1 version 3 [i.5],
clauses 7.2.8.1.11, 9, 11.2, 11.5, F.1, F.3.2, F3.5, F.3.11 or F.4.1.1. A primary MG is denoted by the facts
that:
1) there is a single H.248 Control Association terminated in the MG; and that
2) there may be a secondary MG existing. The association between primary and secondary entity is
given by support for redundancy on network level.
primary Media Gateway Controller (MGC): according to "Primary MG"
secondary Media Gateway (MG): according to "Primary MG"
secondary Media Gateway Controller (MGC): according to "Primary MGC"
NOTE: There can in general be a list of primary and secondary MGCs in each MG.
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10 ETSI TS 183 025 V2.5.1 (2009-04)
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AGW Access GateWay
DSP Digital Signal Processor
FE Functional Entity
IP Internet Protocol
IS In Service
MG Media Gateway
MGC Media Gateway Controller
MGW Media GateWay
NGN Next Generation Network
OOS Out-Of-Service
PE Physical Entity
RTP Real-time Transport Protocol
SC ServiceChange (H.248)
SCTP Stream Control Transmission Protocol
SDO Standardization Development Organizations
SNMP Simple Network Management Protocol
TISPAN Telecommunications and Internet converged Services and Protocols for Advanced Networking
TR Technical Report
UDP User Datagram Protocol
VMG Virtual Media Gateway
4 Reference Architecture
Figure 1 illustrates the reference architecture assumed in the present document.
Management
Commands
MGC
Management
System
H.248.1 Protocol
Procedures
Management
MG
Commands
Figure 1: Reference architecture
The present document discusses the message primitives that may be passed over the Management Command interface
and any related mappings into the H.248 control procedures and vice versa.
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11 ETSI TS 183 025 V2.5.1 (2009-04)
5 H.248 Concepts And Logical Entities
5.1 H.248 Entities
H.248 commands and procedures are acting on H.248 logical entities. These are the different types:
• Context: This is the entity that associates terminations together in a call or session. See also clause 6.1 of [i.5].
• NULL Context: This is a special Context which contains all Physical Terminations that are not associated with
any other Termination. However, commands may still be initiated to and from these terminations. See also
clause 6.1 of [i.5].
• Root Termination: This defines the MGW as an individual entity as a whole. See also clause 6.2.5 of [i.5].
• Physical Termination: This is an entity which has fixed physical characteristics (e.g. an analogue line) and
requires pre-configuration via the management system prior to use within H.248 protocol. For such
terminations, the MGC and MG are pre-provisioned to have a common view of the existing physical
terminations. See also clause 6.2 of [i.5].
• Ephemeral Termination: This is a logical entity representing a dynamically created termination within the
MGW (e.g. IP/RTP). No pre-configured characteristics are required for this type of entity, although in some
profiles the MGC may have a dependency on the MG via the termination naming principles. See also
clause 6.2 of [i.5].
Terminations may be individually addressed or as group (except Root Termination). Group addressing is performed via
H.248 wildcarding.
5.2 H.248 Non-Call Related Commands
The H.248.1 commands relevant to the present document are:
• AuditValue: This command enables a MGC to request the supported packages and current state of properties,
events, signals and statistics of terminations. For further details, see also clause 7.2.5 of [i.5].
• AuditCapability: This command enables a MGC to request all supported values for termination properties,
events and signals allowed by the Media Gateway (i.e. the ROOT Termination). This command is not used in
any of the TISPAN profiles and is thus considered to be out of scope in the present document. For further
details, see also clause 7.2.6 of [i.5].
• ServiceChange: This command enables a MG to notify the MGC that a termination or group of terminations is
about to be taken out of service or has just been returned to service. It also used by the MG to announce its
availability to a MGC (registration), and to notify the MGC of impending or completed restart of the MG. The
MGC may announce a handover to the MG by sending it a ServiceChange command. The MGC may also use
ServiceChange to instruct the MG to take a termination or group of terminations in or out of service. For
further details, see also clause 7.2.8 of [i.5].
• Notify: This command enables a MG to notify the MGC of any event occurring in the MG (that has been
requested by the MGC). The Notify command is applicable to both call and non-call related procedures. Only
the latter is in scope of the present document. For further details, see also clause 7.2.7 of [i.5].
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12 ETSI TS 183 025 V2.5.1 (2009-04)
5.3 H.248 Service State
One of the key descriptors of Terminations in the present document is the ServiceStates property within the Termination
State Descriptor:
Possible values:
InService The termination is in-service and functioning normally.
OutOfService The termination is out-of-service and not available for traffic.
Test The termination is undergoing testing.
The MG/MGC may report changes to the service state via the Service Change Command to its peer. Changes to the
service state can occur due to faults (MG only) or interaction with management commands (MG/MGC). In the latter
case, the H248 Service State is assumed to reflect the overall/resulting availability status of the termination based on the
administrative (i.e. the state of the resource as required by the management interface) and operational (i.e. the state of
the resource based whether it is working correctly or not) states.
Note that the transition into the TEST state has no impact on Service Change procedures. Service change procedures are
impacted only in the transition from TEST to OUT OF SERVICE states (see table F2/H248.1 of [i.5]).
6 Management Primitives
As stated previously, specific management systems, architectures and protocols are outside the scope of the present
document. Rather, the present document considers only a high level set of primitives which directly result in the
triggering of H.248 signalling.
The following management primitives are defined in the present document:
• Create Resource: This command creates a resource. A resource is typically created prior to it being enabled.
This command has no impact on H.248 signalling and is included only for completeness.
• Enable Resource: The resource moves from an OOS to an IS state (assuming that there is no problem with any
related physical state) and is now available for traffic.
• Disable Resource (Graceful): The resource is no longer available to new calls/connections. However, all
existing calls are permitted to terminate naturally at which point the resource moves into the OOS state. If
there are still remaining calls on the resource after a period of time, the operator may invoke the Disable
Resource (Immediate) primitive.
• Disable Resource (Immediate): Any existing calls/connections are force released, at which point the resource
moves into the OOS state.
• Delete Resource: This command deletes a resource. A resource would be disabled prior to it being deleted.
This command has no impact on H.248 signalling and is included only for completeness.
These management primitives (in general) are applicable at both the MG and MGC.
7 Failure/Recovery Scenarios
Certain failure scenarios also result in the triggering of H.248 signalling. The present document defines the following
set of such scenarios:
• Nodal failure and recovery of a MG/MGC. This can be due to hardware or software faults.
• Termination failure and recovery. Examples of this are termination failure/recovery on the MG (e.g. DSP
failure, interface failure such as loss of synchronization on an E1, etc.).
• User plane failure. Examples of this would be detection of loss of RTP media. The MG would inform the
MGC of such failure and the MGC may force release the call.
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13 ETSI TS 183 025 V2.5.1 (2009-04)
• MG-MGC signalling link (control association) failure/recovery. The detection of a signalling link failure
results in H.248 signalling to restore the link. On restoring the link, the MG and MGC may have become out
of step and thus additional H.248 audits are necessary to ensure the re-synchronization of each end.
8 Redundancy Scenarios
The H.248 non call related procedures are also impacted by the redundancy architectures chosen at a MG/MGC.
Examples of such scenarios are:
• MGC Hand-Off. This functionality enables a MGC to terminate an existing control association and establish a
new control association to an alternative MGC. This procedure can be applied to load share or due to
maintenance action.
• MGC Triggered MG Re-direct. This functionality enables a MGC to redirect an attempted registration to an
alternative MGC.
• MG Failover. This functionality enables a MG to inform a MGC that a secondary MG is taking over an
existing control association.
It should be noted that processor redundancy can be achieved within a functional node thus being invisible to the H.248
protocol peer or additionally within the functional node but between logical entities within that node and thus using
H.248 procedures but using the same nodal address. The scope of the present document does not extend to inter-nodal
protocol solutions to support other such redundancy scenarios.
9 General Use Cases
The following use cases and their interaction with the H.248 non-call related procedures are considered in the present
document.
Configuration Management:
• Enable MG.
• Enable MGC.
• Disable MG (Graceful).
• Disable MG (Immediate).
• Disable MGC.
• Enable Termination.
• Disable Termination (Graceful).
• Disable Termination (Immediate).
• Change of MG Resources.
Fault Management - Failure and recovery:
• MG failure and recovery.
• MG termination failure and recovery.
• MGC failure and recovery.
• User plane failure.
• MGC-MG signalling link failure and recovery.
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14 ETSI TS 183 025 V2.5.1 (2009-04)
Performance Management:
• MG Overload.
• MGC Overload.
Node Redundancy:
• MGC Handoff.
• MGC MG Triggered Redirect.
• MG Failover.
10 Interaction Between Use Cases and Non-Call
Related H.248 Procedures
This clause contains high level functional descriptions of the non call-related H.248 procedures in relation to the Use
Cases. There may be multiple procedures relating to one general use case. Clause 11 contains the detailed contents of
each of the cited procedures. The procedure names are denoted by the use of UPPER CASE letters.
10.1 Enable MG
This management primitive is applicable to both the MGC and MG. It is recommended that this primitive is initially
sent to the MGC and subsequently to the MG.
10.1.1 Enable MG (at MGC)
This use case is triggered by management action that results in a MG being enabled at the MGC. There are no H.248
procedures associated with this action. The MGC simply awaits a registration from the MG (see clause 10.1.2).
10.1.2 Enable MG (at MG)
This use case is triggered by management action that results in a MG being brought into service. The MG will have
been provisioned with the identity/address of one or more MGC(s). The H.248 procedures are dependent on whether the
MG undergoes a cold or warm boot and are as follows:
MG Cold Boot
1) The MG registers with one of its (pre-provisioned) MGCs using the MG REGISTRATION (COLD BOOT)
procedure. This step enables the H.248 protocol version to be negotiated as well as the support of any H.248
profiles.
2) In the event of there being no response to the registration request, the MG follows the procedures of
clause 11.5 of [i.5].
3) On completion of the initial registration procedure, the MGC assumes that all physical terminations are in the
NULL context and there are no existing ephemeral terminations. Thus no context/termination related audits
are required to be performed.
4) The MGC may optionally perform a PACKAGES AUDIT procedure in order to determine the MG support of
any optional packages in a mutually supported profile.
5) The MGC may optionally audit ROOT properties (in any mandatory and optional packages) via the AUDIT
ROOT PROPERTIES procedure.
6) The MGC may optionally set properties and events (in any mandatory and optional packages) in the MG on
ROOT level via the SET ROOT TERMINATION EVENTS/PROPERTIES procedure.
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15 ETSI TS 183 025 V2.5.1 (2009-04)
7) The MG may optionally inform the MGC of the state of its physical terminations via a MG TERMINATION
AVAILABLE/MG TERMINATION UNAVAILABLE procedure.
8) The MGC may optionally Audit the state of the physical terminations if it cannot be assumed that the state is
in-service or out-of-service via the AUDIT TERMINATION STATE procedure.
9) The MGC should not deblock associated circuits toward peer nodes before it has determined the true service
state of the MG's circuits by one of the two procedures above.

MGC
MG
MG Initial Registration
MG Initial Registration Ack
Packages Audit
Packages Audit Ack
(optional)
Audit ROOT Properties
(optional)
Audit ROOT Properties Ack
Set ROOT Term Events/Properties
Set ROOT Term Events/Properties Ack
(optional)
MG Termination (Un)Available
(optional)
MG Termination (Un)Available Ack

Audit Termination State
(optional)
Audit Termination State Ack
Figure 2: MG Cold Boot Procedures
MG Warm Boot
1) The MG registers with one of its (pre-provisioned) MGCs using the MG RESTORATION procedure This step
enables the H.248 protocol version to be negotiated as well as the support of any H.248 profiles.
2) In the event of there being no response to the registration request, the MG follows the proce
...