1、 ETSI TS 102 229 V4.1.1 (2003-08)Technical Specification Telecommunications and Internet ProtocolHarmonization Over Networks (TIPHON) Release 4;Interface Protocol Requirements Definition;Aggregate Bearer Load Control - H.248 PackageETSI ETSI TS 102 229 V4.1.1 (2003-08) 2 Reference DTS/TIPHON-03022R4
2、 Keywords bearer, control, H.248, IP, protocol, telephony, voice, VoIP ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7
3、803/88 Important notice Individual copies of the present document can be downloaded from: http:/www.etsi.org The present document may be made available in more than one electronic version or in print. In any case of existing or perceived difference in contents between such versions, the reference ve
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5、tatus. Information on the current status of this and other ETSI documents is available at http:/portal.etsi.org/tb/status/status.asp If you find errors in the present document, send your comment to: editoretsi.org Copyright Notification No part may be reproduced except as authorized by written permi
6、ssion. The copyright and the foregoing restriction extend to reproduction in all media. European Telecommunications Standards Institute 2003. All rights reserved. DECTTM, PLUGTESTSTM and UMTSTM are Trade Marks of ETSI registered for the benefit of its Members. TIPHONTMand the TIPHON logo are Trade M
7、arks currently being registered by ETSI for the benefit of its Members. 3GPPTM is a Trade Mark of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. ETSI ETSI TS 102 229 V4.1.1 (2003-08) 3 Contents Intellectual Property Rights4 Foreword.4 Introduction 4 1 Scope 6
8、 2 References 6 3 Definitions and abbreviations.6 3.1 Definitions6 3.2 Abbreviations .7 4 Reference architecture7 5 General load control functions .8 6 Admission control - aggregate capacity availability 8 6.1 Support of different media types 8 6.2 Support of High/Low load thresholds 8 6.3 Load Cont
9、rol message from ABM to ABAC .9 6.4 Admission control mechanism .9 6.4.1 ABAC admission control9 6.4.2 Media Layer admission control (ABM in media layer application) .9 7 Admission control - transport network QoS performance10 8 Traffic management support - Capacity event report and capacity statist
10、ics .10 9 Load Control primitives and parameters10 Annex A (normative): Aggregate Bearer Load Control (ABLC) - H.248 Package11 A.1 Events.11 A.1.1 Aggregate Load Control Capacity Alarm11 A.1.2 Capacity event - Report12 A.1.3 AggregateQoS 13 A.2 Statistics .14 History 16 ETSI ETSI TS 102 229 V4.1.1 (
11、2003-08) 4 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: “Intellectu
12、al 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 investigati
13、on, 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 Specificatio
14、n (TS) has been produced by ETSI Project Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON). Introduction Aggregate Bearer functionality in ETSI TIPHON has been first described in TS 101 329-3 2. With aggregated transport resource reservation or bulk reservation the IP Tel
15、ephony Application Plane reserves an amount of resources for media transport that is sufficient to support a number of media flows. This allows the application plane to more efficiently use allocated resources by using statistical multiplexing of variable bit-rate media streams. Resource aggregation
16、 may be performed in the Transport Plane under the control of either Transport Network Operators or IP Telephony Service Provider (ITSP). Aggregation involves a quantity of transport resource with guaranteed QoS characteristics being allocated prior to the set up of an individual media flow. Individ
17、ual media flows will then consume a portion of this. When control of the aggregated resource is performed by a Service Provider, an IP Telephony application may reserve a quantity of transport resource with quaranteed QoS characteristics prior to the set up of an individual media flow. This would be
18、 by agreement with the Transport Network Operator. The IP Telephony application then maintains the availability of QoS reserved resource calculating the actual utilization of the aggregate resource. Resource aggregation requires aggregate bearer bandwidth management and connection admission control
19、functionality. The following methods are identified for aggregate resource creation: a) provisioning on a semi-permanent basis (pre-assigned); b) dynamic aggregate resource establishment/clear down. A dynamic aggregate may also be implemented with optional bandwidth negotiation. Connection admission
20、 control to the aggregate resource shall be performed on a per call flow basis. The resource usage information may be used for connection admission control. Aggregate resource usage can be calculated by different methods, e.g.: a) traffic engineering methods taking into account Traffic Descriptors;
21、b) resource usage measurements. Resource reservation renegotiation may take place at any time. For example when the resource usage of the aggregate flow exceeds a predetermined percentage of the reserved resource the allocation may be renegotiated or a new aggregate flow created. Similarly in low tr
22、affic conditions it may be desirable to renegotiate a lower aggregate reservation. ETSI ETSI TS 102 229 V4.1.1 (2003-08) 5 The present document supports the following methods: - Aggregate Resource Creation: Provisioned aggregate bearer creation. - Aggregate Resource Usage: Resource usage measurement
23、s. ETSI ETSI TS 102 229 V4.1.1 (2003-08) 6 1 Scope The present document defines the aggregate load control information flows which are part of the N2 and N3 reference points network architecture as described in TS 101 882 release 4 1. The present document is supporting only provisioned aggregate bea
24、rer functionality. Mixing of different bearer capabilities of PSTN/ISDN service over the same aggregate bearer is supported. The aggregate bearer is provisioned with a single set of QoS parameters. 2 References The following documents contain provisions which, through reference in this text, constit
25、ute provisions of the present document. 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. For a non-specific reference, the latest version applies. Referenced docume
26、nts which are not found to be publicly available in the expected location might be found at http:/docbox.etsi.org/Reference 1 ETSI TS 101 882 (all parts): “ Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON) Release 4; Protocol Framework Definition“. 2 ETSI TS 101 329-3: “
27、 Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON) Release 3; End-to-end Quality of Service in TIPHON systems; Part 3: Signalling and control of end-to-end Quality of Service (QoS)“. 3 ITU-T Recommendation H.248: “Gateway control protocol 3“. 4 ITU-T Recommendation Q.50:
28、“Signalling between Circuit Multiplication Equipment (CME) and International Switching Centres (ISC)“. 5 IETF RFC 1889: “RTP: A Transport Protocol for Real-Time Applications“. 3 Definitions and abbreviations 3.1 Definitions For the purposes of the present document, the following terms and definition
29、s apply: aggregate bearer: logical association of functional entities in an IP Telephony application and Transport Network which creates one or more concurrent end to end media flows and which is not limited to the duration of a single call Aggregate Bearer Admission Control (ABAC) function: functio
30、nal entity that determines whether or not a flow is to be admitted as part of an established Aggregate Bearer Aggregate Bearer Measurement (ABM) function: function that determines the capacity used and remaining in an aggregate bearer as a result of measuring the actual media flows after taking into
31、 account what flows were requested InterConnection Function (ICF): functional entity connecting two networks having differing administrative policy such as Quality of Service (QoS) or addressing policy but employing the same signalling protocol, and transport technology, at the point of interconnect
32、 ETSI ETSI TS 102 229 V4.1.1 (2003-08) 7 Transport Resource Manager (TRM): functional entity that applies a set of policies and mechanisms to a set of transport resources to ensure that those resources are allocated such that they are sufficient to enable transport flows with QoS guarantees across t
33、he domain of control of the TRM 3.2 Abbreviations For the purposes of the present document, the following abbreviations apply: ABAC Aggregate Bearer Admission Control ABLC Aggregate Bearer Load Control ABM Aggregate Bearer Measurement BC Bearer Control CC Call Control ICF Interconnection functionMG
34、= Media Gateway ITSP IP Telephony Service Provider MGC Media Gateway Control QoS Quality of Service RTP Real Time Protocol TMR Transmission Medium Requirement TRM Transport Resource Manager 4 Reference architecture The aggregate load control information flows are part of the N2 and N3 reference poin
35、ts in the ETSI-TIPHON architecture (see TS 102 882 series 1). The Aggregate Bearer Admission Control (ABAC) function determines whether or not a flow is to be admitted as part of an established Aggregate Bearer. It also keeps track of the capacity available for flows as they may change for reasons o
36、ther than the admission or cessation of media flows. The Aggregate Bearer Measurement (ABM) function determines the capacity used and remaining in an Aggregate Bearer as a result of measuring the actual media flows after taking into account what flows were requested. Aggregate load control informati
37、on flow may also be applied on the I3 reference point of TS 102 882 series 1. TRMIC FIC FABACLoadControlABMTRIC FFigure 1: Aggregate Load Control application ETSI ETSI TS 102 229 V4.1.1 (2003-08) 8 5 General load control functions Load Control information flows between ABM and ABAC provide the capab
38、ility to provide admission control functionality based on aggregate bandwidth usage measurements and transport network QoS performance. The load control shall enable the following functions: a) Admission control based on aggregate capacity availability. b) Admission control based on transport networ
39、k QoS performance. c) Support of traffic management (e.g. load balancing, codec rate reduction etc.) by means of bandwidth usage (or unused bandwidth) report. 6 Admission control - aggregate capacity availability 6.1 Support of different media types Load control may be performed per Media types. ITU
40、-T Recommendation Q.50 4 defines load control for two Transmission Medium Requirement (TMR) types: 3,1 kHz audio or speech - capacity available/unavailable 64 kbit/s unrestricted - capacity available/unavailable For traffic originating from the PSTN/ISDN, the load control protocol shall support the
41、aggregation of different PSTN/ISDN bearer capabilities over the same aggregate bearer. Bearer capabilities are described as Media types. 6.2 Support of High/Low load thresholds When the bandwidth usage of the aggregate flow exceeds a predetermined percentage of the reserved bandwidth (High_threshold
42、) “capacity unavailability“ shall be declared. “Capacity unavailability“ shall be changed to “ Capacity available“ when the bandwidth usage of the aggregate flow is below a predetermined percentage of the reserved bandwidth (Low_threshold). ETSI ETSI TS 102 229 V4.1.1 (2003-08) 9 CapacityAvailableCa
43、pacityUnavailableCapacityAvailableHighThresholdLowThresholdTimeAggregateUsageFigure 2: Example of capacity Available/Unavailable transitions It shall be possible to define the following types of load thresholds: High/Low threshold of bandwidth usage of total aggregate (percentage). Optionally the th
44、resholds may be set in addition also per media type: High/Low threshold of bandwidth usage of media type (percentage). 6.3 Load Control message from ABM to ABAC Load threshold passing shall be indicated from the ABM to the ABAC. The load control message from ABM to ABAC shall consist of: - The statu
45、s of the capacity (available/unavailable), and the media type. NOTE: One of the media types shall represent the total aggregate (i.e. all media types). 6.4 Admission control mechanism 6.4.1 ABAC admission control The ABAC shall not admit any new calls to the aggregate after reception of “aggregate c
46、apacity unavailable“ message. Reception of “aggregate capacity available“ message will enable again the admission of new calls to the aggregate. How the MGC handles calls that cannot be admitted to an aggregate bearer is implementation dependent. 6.4.2 Media Layer admission control (ABM in media lay
47、er application) For ABM implementations in the media layer the following procedure may be applied: - The media layer may reject the admission of a call to the aggregate during any phase of the connection establishment process. i.e. even if the ABAC has admitted a call to the aggregate, the media lay
48、er may still reject the connection request. This mechanism takes into account that the most updated information about aggregate bearer usage resides in the media layer ABM functional unit. This mechanism also resolves any possible inconsistencies between ABAC and media layer. ETSI ETSI TS 102 229 V4
49、.1.1 (2003-08) 107 Admission control - transport network QoS performance An aggregate is provisioned with a set of QoS parameters. In spite of the aggregate being provisioned with a set of QoS performance parameters, the transport network performance may deteriorate during the lifetime of the aggregate. A new call shall be admitted by the ABAC function, only if the per call QoS parameters requirement can be accommodated with the current transport network QoS parameters. QoS performance notifications may be obtained from the transport layer vi
