1、STD-ETSI TR LO1 123-ENGL 1997 R 3Li00855 02445b4 573 R TR 1 O1 123 1.1.1 (1997-11) I Technical Repon Broadband Integrated Services Digital Network (B-ISDN); Resource management procedures and cases of their possible usage 2 TR 101 123 Vl.l.1 (1997-11) Reference DTFUNA-052809 (aecOOics.PDF) Keywords
2、ATM, B-ISDN, control, management, traffic ETSI Secretariat Postai address F-O6921 Sophia Antipolis Cedex - FRANCE Office address 650 Route des Lucioles - Sophia Antipolis Valbonne - FRANCE Tel.: +33 4 92 94 42 O0 Fax: +33 4 93 65 47 16 Siret No 348 623 562 00017 - NAF 742 C Association but non lucra
3、tif enregistre la Sous-Prfecture de Grasse (06) No 7803/88 X.400 c= fr; a=atlas; p=etsi; s=secretariat Internet secretariata et.s.fr http:/www.etsi.f r Copyright Notification No part may be reproduced except as authorized by written permission. The copyright and the foregoing restriction extend to r
4、eproduction in ail media. O European Telecommunications Standards Institute 1997. Ail rights reserved. 3 TR 101 123 Vl.l.1 (1997-11) Contents Intellectual Property Rights 5 Foreword 5 1 Scope 6 2 References 6 3 Abbreviations . 6 4 General principles 7 ABT/DT Protocol description 7 5 5.1 Introduction
5、 7 5.2 Notation and conventions 8 5.3 Functions supported by the ABT/DT protocol . 9 5.3.1 5.3.2 User maintenance functions 10 5.3.3 Traffic control functions . 10 5.3.4 Network maintenance functions 11 5.3.4.1 5.3.4.2 Other Network Maintenance functions . 5.4 RM cell format . 11 5.5 Protocol messag
6、es 12 5.5.1 BCR negotiation messages . 12 5.5.1.1 Rigid BCR negotiation . 12 5.5.1.2 Elastic BCR negotiation . 12 5.5.2 5.5.2.1 Forward and backward status enquiry . 13 5.5.3 Traffic control messages 13 5.5.3.1 Rigid traffic control 13 5.5.3.2 Elastic traffic control 14 5.5.4 Network maintenance mes
7、sages . 14 5.6 Normal protocol procedures . 14 5.6.1 5.6.1.2 Rigid BCR negotiation procedures 16 5.6.1.2.1 Rigid forward BCR decrease 16 5.6.1.2.2 5.6.1.2.3 Rigid backward BCR increase or decrease . 17 5.6.1.3 Elastic BCR negotiation procedures . 19 5.6.1.3.1 Elastic forward BCR increase . 19 5.6.1.
8、3.2 Elastic backward BCR increase 19 5.6.2 User maintenance procedures . 20 5.6.2.1 Forward status enquiry procedures . 21 5.6.2.2 5.6.3 5.6.3.1 5.6.3.1.1 5.6.3.1.2 5.6.3.2 5.6.3.2.1 5.6.3.2.2 5.6.4 5.6.4.1.1 5.6.4.1.2 BCR negotiation functions . 9 Time-out handling functions . 11 User maintenance m
9、essages . 13 5.5.2.2 Not ready 13 5.5.4.1 Time-out handling . 14 BCR negotiation procedures . 15 5.6.1.1 General principles 15 Rigid forward BCR increase . 16 Backward status enquiry procedures 21 Traffic control procedures 21 Rigid traffic control procedures 21 Elastic traffic control procedures 23
10、 Rigid forward traffic control . 21 Rigid backward traffic control 22 Elastic forward traffic control . 23 Elastic backward traffic control 23 Network maintenance procedures 24 Timers associated with ABT/DT procedures 24 5.6.4.1 Time-out handling procedures . 24 Recovering from ingress Time-out . 27
11、 STD-ETSI TR 101 123-ENGL 1997 3400855 02445b7 2T2 = 5.6.4.1.3 5.6.4.1.4 5.7 5.7.1 5.7.2 5.7.3 5.7.3.1 5.7.3.2 5.7.3.3 5.7.3.4 4 TR 101 123 Vl.l.1 (1997-11) Recovering from Egress Time-out . 28 Further considerations . 29 Behaviour in the case of collision of different procedures . 30 Collision at t
12、he ingress node 30 Collision at the egress node 30 Collision within the network . 30 Collision between forward and backward BCR negotiation . 31 Collision between backward BCR negotiation and Forward Traffic Control procedures . 32 Collision between forward BCR negotiation and backward traffic contr
13、ol procedures 33 Collision between forward and backward traffic control procedures . 35 6 Cases of possible applications . 36 6.1 Support of A-VPN . 36 Annex A: Reference behaviours . 38 A . 1 Source reference behavio ur 38 A.2 Destination reference behaviour 41 A.3 Network element reference behavio
14、ur 43 A.3.2 Intermediate node 46 A.4 Further considerations 52 History 53 A.3.1 Ingress node . 43 A.3.3 Egress node 49 STD-ETSI TR 101 123-ENGL 1997 3Li00055 02Li45bB 139 m 5 TR 101 123 V1.l.l (1997-11) Intellectual Property Rights PRs essentiai or potentially essential to the present document may h
15、ave been declared to ETSI. The information pertaining to these essential PRs, if any, is publicly available for ETSI members and non-members , and can be found in ETR 314: “Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“,
16、which is available free of charge from the ETSI Secretariat. Latest updates are available on the ETSI Web server (http: / www .et si. fdipr). hrsuant to the ETSI interim IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence
17、of other IPRs not referenced in ETR 314 (or the updates on http:/www.etsi.fr/ipr) which are, or may be, or may become, essential to the present document. Foreword This Technical Report (TR) has been produced by ETSI Technical Committee Network Aspects (NA). 6 TR 101 123 Vl.l.1 (1997-11) 1 Scope The
18、present document is to define a specific resource management protocol to support the transfer ABT-DT capability and to consider some specific cases of its possible application. The material contained in the present document is strictly informative to give guidance for implementation in networks. No
19、additional ATM transfer capabilities as compared to FU-T Recommendation 1.371 i are introduced. The present document specifies the functions supported by the ABT-DT protocol, the-protocol messages and the protocol procedures. in order to achieve an effective resource management capability, these fun
20、ctions shall be complemented by additional functions (e.g. connection policing, resource allocation) that are network operator specific and are not covered by the present document. 2 References References may be made to: a) specific versions of publications (identified by date of publication, editio
21、n number, version number, etc.), in which case, subsequent revisions to the referenced document do not apply; or b) all versions up to and including the identified version (identified by “up to and including“ before the version identity); or c) all versions subsequent to and including the identified
22、 version (identified by “onwards“ following the version identity); or d) publications without mention of a specific version, in which case the latest version applies. A non-specific reference to an ETS shall also be taken to refer to later versions published as an EN with the same number. Pl ITU-T R
23、ecommendation .371: “Traffic Control and Congestion Control in B-ISDN; 3 Abbreviations For the purposes of the present document the following abbreviations apply: ABT ABT-DT ATM BCR B -VPN FRh4 IBT OAM QOS RM SCR ATM Block Transfer ATM Block Transfer with Delayed Transmission Asynchronous Transfer M
24、ode Block Cell Rate Broadband Virtual Private Network Fast Resource Management intrinsic Burst Tolerance Operation And Maintenance Quality of Service Resource Management Sustainable Cell Rate 7 TR 101 123 Vl.l.1 (1997-11) 4 General principles The protocol specified in the present document is an appl
25、ication of Fast Resource Management (FRM) techniques, specifically designed to support the ABT/DT transfer capability. FRM techniques operate on the time scale of the round-trip propagation delay of an ATM connection and allow the modification of the ATM resources allocated to a connection depending
26、 on the actual need of the connection and/or on the network status. A basic characteristic of FRM procedure is that the command messages required by the specific protocol are transported “in band“ into the data flow by means of specific Resource Management (RM) cells. This is intended to improve the
27、 protocol response time. The general format of RM cells is specified in EU-T Recommendation 1.371 i as well as the specific RM cell format used by the ABT/DT protocol. 5 ABT/DT Protocol 5.1 I nt roduction description This subclause presents the specification of a protocol for supporting the ATM Bloc
28、k Transfer with Delayed Transmission (ABTDT) capability. The high level description of ABT/DT as well as the definition of the ATM block are given in IT-T Recommendation 1.371 i. The basic principle behind ABT/DT is that the information is transmitted in block of cells (ATM Blocks) and that the band
29、width available for transmission, Le., the Block Cell Rate (BCR), is negotiated individually for each ATM Block. ATM Blocks are delineated by specific messages of the ABT/DT protocol, as will be specified later on in the present document. In the present specification, only point-to-point bidirection
30、al communications are considered and the protocol is limited to a single network; point-to-multipoint communications are for further study. Even though the ABTDT transfer capability may usually involve bi-directional data transmission, for the sake of simplicity the description provided by the prese
31、nt document refers only to a single direction of data transmission, the generalization to the bi-directional case being straightforward. With this restriction the reference configuration for an ABT/DT connection is shown in figure 1. The terminal originating the data is said to be the Source termina
32、l and the terminal receiving the data is said to be the Destination terminal. Between the two terminals there is a mono-directional data flow (from the source toward the destination) and a bi-directional control flow realized by means of RM cells. The direction of the control flow going from the sou
33、rce toward the destination is said to be the Forward direction; the reverse direction is said to be the Backward direction. Furthermore, the network node closest to the source is said to be the Ingress node; the one closest to the destination is said to be the Egress node. Network Node n 7r Figure 1
34、 : Reference configuration for ABTIDT Each direction of transmission is realized by means of an ABTDT connection, whose traffic contract specifies: 1) -The peak cell rate value for each cell flow of the connection, namely: - the maximum cell rate of the user generated CLP=O+l cell flow (including us
35、er OAM but no RM cells); 8 TR 101 123 Vl.l.1 (1997-11) - the maximum cell rate of the user OAM cell flow. Note that in the signalling message this peak cell rate is declared as a proportion of the aggregate peak cell rate Amax(o+i). Only the first parameter is mandatory; the second one is optional.
36、Values of these two parameters are upperbounds for the respective negotiable BCR values of the different cell flows. 2) The CDV tolerance associated with each maximum cell rate, namely: - - CDV Tolerances may be implicitly or explicitly declared (note i). z,(+) of the CLP=O+1 cell flow (mandatory);
37、zm(om) of the OAM cell flow (optional and possibly implicit). 3) The maximum frequency of BCR negotiations by means of: - the peak cell rate 1/T, of the user request RM cells. 4) The CDV tolerance zRM associated with the peak cell rate of the user request RM cell flow. 5) The committed bandwidth of
38、the CLP=O+l cell flow by means of a Sustainable Cell Rate (SCR) and an Intrinsic Burst Tolerance (IBT); the SCR may be set equal to O. 6) The requested QoS class. NOTE 1: The CDV tolerance z associated with the CLP=O+1 cell flow may depend on the peak cell rate h of this cell flow, namely z is a fun
39、ction r(h) of h. in that case, the function z(h) is specified on a subscription basis and zm,(O+l)=z(Am,(O+l) . The CDV tolerance associated with OAM traffic should satisfy the general requirements given in Appendix i to FU-T Recommendation 1.371 i. An ABT/DT connection is subject to Connection Admi
40、ssion Control (CAC) on the basis of the declared parameters (peak and sustainable cell rates). At the establishment of an ABT/DT connection, the connectivity between the source and the destination is assured but no resources are allocated; the connection is then said domnt. Resources are allocated o
41、nly via BCR negotiation by means of RM cells and the connection is then said active. 5.2 Notation and conventions The following conventions are used in the present document in order to identify the different cell flows generated by a user terminal: - - - - OAM cell flow: includes only end to end OAM
42、 cells generated by the user; RM cell flow: includes any kind of RM cells generated by the user, user data CLP=O+l cell flow: includes all user data cells, regardless the value of the CLP bit; aggregated CLP=O+l cell flow: includes all user data cells and OAM cells, but not RM cells. Furthermore, th
43、e following symbols will be used in the rest of the present document: - - h(0+1): a generic value of the BCR for the aggregated CLP=Cl+l cell flow; A(0AM): a generic value of the BCR for the OAh4 cell flow; - kurrent(O+l): value of the BCR for the aggregated CLP=O+l cell flow currently allocated to
44、a connection at the ingress node; - - hc,(OAM): value of the BCR for the OAM cell flow Currently allocated to a connection at the ingress node; kment(O+l): value of the BCR for the aggregated CLP=O+l cell flow currently allocated to a connection at the Egress node; kment(OAM: value of the BCR for th
45、e OAM cell flow currently allocated to a connection at the Egress node; - STD-ETSI TR 101 123-ENGL 1797 D 3LI00855 0244572 bbT D 9 TR 101 123 V1.1.1 (1997-11) - AN(O+l): value of the BCR for the aggregated CLP=O+l cell flow currently allocated to a connection at the generic node N, AN(0AM): value of
46、 the BCR for the OAM cell flow currently allocated to a connection at the generic node N; - - Ac,(O+l): value of the BCR for the aggregated CLP=O+l cell flow currently reserved but not yet allocated to a connection at the ingress node; - Acwent(OAh4): value of the BCR for the OAM cell flow currently
47、 reserved but not yet allocated to a connection at the Ingress node; hc,(O+l): value of the BCR for the aggregated CLP=O+l cell flow currently reserved but not yet allocated to a connection at the Egress node; - - XCwe,(OAM): value of the BCR for the OAM cell flow currently reserved but not yet allo
48、cated to a connection at the Egress node; AReq(O+l): value of the BCR for the aggregated CLP=O+l cell flow requested by the source; ARq(OAM): value of the BCR for the OAM cell flow requested by the source; hRq(O+l): value of the BCR for the aggregated CLP=O+l cell flow requested by the destination;
49、hR,(OAM): value of the BCR for the OAM cell flow requested by the destination; AdoC(O+1): value of the BCR for the aggregated CLP=O+l cell flow that has been allocated following a negotiation request; - - - - - - h,(OAM): value of the BCR for the OAM cell flow that has been allocated following a negotiation request; 5.3 Functions supported by the ABT/DT protocol 5.3.1 BCR negotiation functions The BCR negotiation functions are the basic functions supported by the ABT-DT protocol. By means of these functions the user terminals may negotiate wit
