SIST ETS 300 010-2 E1:2003
(Main)Transmission and Multiplexing (TM); Synchronous cross connect equipment; 64 kbit/s and n x 64 kbit/s cross connection rate 2 048 kbit/s access ports; Part 2: Management aspects
Transmission and Multiplexing (TM); Synchronous cross connect equipment; 64 kbit/s and n x 64 kbit/s cross connection rate 2 048 kbit/s access ports; Part 2: Management aspects
Draft ETS 300 010-2 covering management ascpects of 64 kbit/s DXCs
Prenos in multipleksiranje (TM) – Oprema za sinhrono prespajanje za 64 kbit/s in n x 64 kbit/s za dostopovne porte s hitrostjo prespajanja 2 048 kbit/s – 2. del: Vidiki upravljanja
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2003
Prenos in multipleksiranje (TM) – Oprema za sinhrono prespajanje za 64 kbit/s in n
x 64 kbit/s za dostopovne porte s hitrostjo prespajanja 2 048 kbit/s – 2. del: Vidiki
upravljanja
Transmission and Multiplexing (TM); Synchronous cross connect equipment; 64 kbit/s
and n x 64 kbit/s cross connection rate 2 048 kbit/s access ports; Part 2: Management
aspects
Ta slovenski standard je istoveten z: ETS 300 010-2 Edition 1
ICS:
33.040.20 Prenosni sistem Transmission systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN ETS 300 010-2
TELECOMMUNICATION March 1997
STANDARD
Source: ETSI TC-TM Reference: DE/TM-01014-3
ICS: 33.020
Key words: Cross connect, digital, management, transmission, SDH, leased line
Transmission and Multiplexing (TM);
Synchronous cross connection equipment
64 kbit/s and n x 64 kbit/s
cross connection rate 2 048 kbit/s access ports;
Part 2: Management aspects
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: secretariat@etsi.fr
Tel.: +33 4 92 94 42 00 - Fax: +33 4 93 65 47 16
Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the
foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1997. All rights reserved.
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ETS 300 010-2: March 1997
Whilst every care has been taken in the preparation and publication of this document, errors in content,
typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to
"ETSI Editing and Committee Support Dept." at the address shown on the title page.
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ETS 300 010-2: March 1997
Contents
Foreword .5
1 Scope .7
2 Normative references.7
3 Abbreviations.8
4 DXC management network.10
5 Information model .10
6 Management interfaces.11
7 Applications functions.11
7.1 Fault management.11
7.1.1 Alarm surveillance.11
7.1.1.1 Principle.11
7.1.1.2 Alarm-related functions.13
7.1.2 Alarm classification.14
7.1.2.1 Alarm type.14
7.1.2.1.1 Communications alarm.14
7.1.2.1.2 Equipment alarms.14
7.1.2.1.3 Processing alarm.15
7.1.2.1.4 Environmental alarm.15
7.1.2.2 Perceived severity level .15
7.1.2.3 Alarm record .16
7.1.3 Test functions.16
7.1.3.1 Loopbacks .16
7.1.3.1.1 Loopbacks at the 2 048 kbit/s level.16
7.1.3.1.2 n x 64 kbit/s dropping function.17
7.1.3.1.3 Internal n x 64 kbit/s loopback .18
7.1.3.1.4 Loopback characteristics .18
7.1.3.1.5 Internal tests .18
7.2 Performance management .18
7.2.1 Long term performance evaluation .19
7.2.2 Short term performance evaluation.19
7.2.2.1 Elementary events for in-service measurement .19
7.2.2.1.1 Anomaly event, receive part .19
7.2.2.1.2 Anomaly event, transmit part .20
7.2.2.1.3 Defect events, receive part .20
7.2.2.1.4 Defect events, transmit part.20
7.2.2.2 Elementary events for out-of-service measurement.20
7.2.3 Condition of measurement .20
7.2.4 Performance parameters evaluation.21
7.2.5 Performance process.21
7.2.5.1 15 minute process .21
7.2.5.1.1 Option 1 - evaluation without
hysteresis.22
7.2.5.1.2 Option 2 - Evaluation with hysteresis.23
7.2.5.2 24 Hour process .23
7.2.6 Performance evaluation .24
7.2.7 General performance functional diagram.25
7.3 Configuration management .26
7.3.1 Configuration management overview.26
7.3.1.0 Glossary.26
7.3.1.1 Functional architecture .27
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ETS 300 010-2: March 1997
7.3.1.1.1 Main functions . 27
7.3.1.1.2 CAS cross-connection functions . 28
7.3.1.1.3 Transfer of unstructured CCITT
Recommendation G.703 / 2 048 kbit/s. 29
7.3.1.1.4 Synchronization function . 30
7.3.1.1.5 Time Slot 0 cross-connection
functions. 30
7.3.1.1.5.1 4 kbit/s granularity . 30
7.3.1.1.5.2 64 kbit/s granularity . 33
7.3.1.2 Object classes. 35
7.3.1.3 Entities-relationships diagrams . 35
7.3.2 Description of the fragments. 38
7.3.2.1 Managed element fragment. 39
7.3.2.2 Termination point fragment. 42
7.3.2.3 Cross-connection fragment. 47
7.3.2.4 Synchronization fragment . 51
7.3.2.5 Power feeding fragment. 55
7.3.2.6 Time Slot 0 cross-connection. 56
7.3.2.6.1 4 kbit/s granularity . 56
7.3.2.6.1.1 Termination point fragment . 56
7.3.2.6.1.2 Cross-Connection fragment . 58
7.3.2.6.2 64 kbit/s granularity . 59
7.3.2.6.2.1 Termination point fragment . 59
7.3.2.6.2.2 Cross-Connection fragment . 63
Annex A (informative): Management functions .65
A.1 Object classes . 65
A.2 Entities-relationship diagrams. 65
A.3 Cross-connection fragment . 67
A.4 Management fragment . 67
History. 68
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ETS 300 010-2: March 1997
Foreword
This European Telecommunication Standard (ETS) has been produced by the Transmission and
Multiplexing (TM) Technical Committee of the European Telecommunications Standards Institute (ETSI).
The ETS is required in order to meet the requirements of network operators and equipment
manufacturers for the deployment and design of synchronous cross connect equipment to be used in
synchronous digital leased line networks.
The corresponding standard for equipment used in cross connection of subrate signals is under
development.
This ETS consists of 2 parts as follows:
Part 1: "Core functions and characteristics";
Part 2: "Management aspects".
Transposition dates
Date of adoption 21 February 1997
Date of latest announcement of this ETS (doa): 30 June 1997
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 31 December 1997
Date of withdrawal of any conflicting National Standard (dow): 31 December 1997
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ETS 300 010-2: March 1997
Blank page
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ETS 300 010-2: March 1997
1 Scope
This ETS addresses management aspects of the 64 (or n x 64) kbit/s cross connect. The Digital Cross
Connect (DXC) equipment management functions are specified and management network architecture is
described.
Part 1 of this ETS describes requirements of cross connect equipment with 2 048 kbit/s access ports for
use in synchronous digital leased line networks. These requirements are limited to the basic functions,
external characteristics and performance of the equipment.
The part 1 of this ETS (ETS 300 010-1[14]) defines functions and makes precise whether they are
mandatory or not. If supported, a function has to be managed according to part 2 of this ETS. Part 2 of
this ETS specifies when necessary the optional management characteristics (attributes, operations and
notifications) of the objects.
2 Normative references
This ETS incorporates by dated or undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications
apply to this ETS only when incorporated in it by amendment or revision. For undated references, the
latest edition of the publication referred applies.
[1] CCITT Recommendation G.703: "Physical/electrical characteristics of
hierarchical digital interfaces".
[2] CCITT Recommendation G.704: "Synchronous frame structures used at primary
and secondary hierarchical levels".
[3] ITU-T Recommendation G.826: "Error performance parameters and objectives
for international, constant bit-rate digital paths at or above the primary rate".
[4] ITU-T Recommendation M.20: "Maintenance philosophy for telecommunications
networks".
[5] ITU-T Recommendation M.2100: "Performance limits for bringing into service
and maintenance of international digital paths, sections and transmission
systems".
[6] ITU-T Recommendation M.2110: "Bringing into service international digital
paths, sections and transmission systems".
[7] ITU-T Recommendation M.2120: "Digital path, section and transmission system
fault detection and localization procedures".
[8] ITU-T Recommendation M.3010: "Principles for a telecommunications
management network".
[9] ITU-T Recommendation M.3100: "Generic network information model".
[10] ITU-T Recommendation O.151: "Error performance measuring equipment
operating at the primary rate and above".
[11] CCITT Recommendation X.710: "Common management information service
definition for CCITT applications".
[12] ITU-T Recommendation X.733: "Information technology - Open Systems
Interconnection - Systems Management: Alarm reporting function".
[13] ITU-T Recommendation G.784: "Synchronous digital hierarchy (SDH)
management".
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ETS 300 010-2: March 1997
[14] ETS 300 010-1 (1995): "Transmission and Multiplexing (TM); Synchronous
cross connect equipment 64 and n x 64 kbit/s cross connection rate 2 048 kbit/s
access ports. Part 1: Core functions and characteristics".
[15] ETS 300 371 (1994): "Transmission and Multiplexing (TM); Plesiochronous
Digital Hierarchy (PDH) information model for the Network Element (NE) view".
[16] ETR 135 (1994): "Transmission and Multiplexing (TM); Network aspects and
applications for a 4 (and n x 4 kbit/s) data link in a 2 048 kbit/s frame".
[17] ETR 241: "Transmission and Multiplexing (TM); Functional architecture of
2 Mbit/s based Plesiochronous Digital Hierarchy (PDH) transport networks".
[18] ITU-T Recommendation X.731: "Information technology - Open Systems
Interconnection - Systems Management: State management function".
[19] ETS 300 304 (1994): "Synchronous Digital Hierarchy (SDH) information model
for the network element (NE) view".
[20] ETS 300 376-1: "Signalling Protocols and Switching (SPS); Q3 interface at the
Access Network (AN) for configuration management of V5 interfaces and
associated user ports".
3 Abbreviations
For the purposes of this ETS, the following abbreviations apply:
2 048S 2 048 kbit/s CCITT Recommendation G.704 [2] framed Signal
2 048U 2 048 kbit/s Unstructured signal
2MB 2 Mbit/s
2ME 2 Mbit/s - External remote
2MI 2 Mbit/s - Internal local
A2, J1, J2, reference points according to ETS 300 010-1 [14]
A-bit bit 3, TS0 FAS
AE Anomaly Event
AIS 2 048 kbit/s Alarm Indication Signal
AISTS16 64 kbit/s Alarm Indication Signal in TS16
BBE Background Block Error
BBER Background Block Error Ratio
BE Block Error
CASXC Channel Associated Signalling Cross Connection Function
CPU Control Processing Unit
CRC4 Cyclic Redundancy Check procedure-4
DE Defect Event
DFC Defect or Failure Condition
DP Degraded Performance
DXC Digital Cross Connect equipment
EB Errored Block
E-bit Remote block error indication
EOC Embedded Operation Channel
ES Errored Second
ESR Errored Second Ratio
EXBER Excessive Bit Error Ratio
F A management interface according to ITU-T Recommendation M.3010 [8]
FAS Frame Alignment Signal
G1, G2, A1, reference points according to ETS 300 010-1 [14]
G1a, G1b, reference points according to ETS 300 010-1 [14]
G'2, A'1, A'2 reference points according to ETS 300 010-1 [14]
G2a, G2b, reference points according to ETS 300 010-1 [14]
H Hour
J'1, J'2, G'1, reference points according to ETS 300 010-1 [14]
LC Local Control interface
LMFA Loss of Multiframe Alignment
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ETS 300 010-2: March 1997
LOF Loss of Frame
LOS Loss of Signal
LSYNC Loss of Synchronization
m m reference point according to ITU-T Recommendation M.3010 [8]
M Mandatory
MCF Message Communication Function
MD Mediation Device
min Minute
NE Network Element
NEF Network Element Function
NP Normal Performance
O Optional
OS Operations System
OSF Operations System Function
PI Physical Interface
PLPT Plesiochronous Lower order Path Termination
POH Path Overhead
PPT Plesiochronous Path Termination
PRBS Pseudo Random Bit Sequence
Q Management interface to the TMN
Q3 A management interface according to ITU-T Recommendation M.3010 [8]
Qx A management interface between a Q-adaptation function (QAF) and a
Network Element Function (NEF) according to ITU-T Recommendation
M.3010 [8]
RAI Remote Alarm Indication
RMAI Remote Multiframe
RTR1ES Reset Threshold for Errored Second counting
RTR1SES Reset Threshold for Severely Errored Second
s Second
Sa Spare bit in TS0 NFAS
San A spare bit in TS0 NFAS
SDH Synchronous Digital Hierarchy
SER Severely Errored Second ratio
SES Severely Errored Second
T1 Internal timing signal
T4 Output timing signal
TIPI Timing Input Physical Interface
TMN Telecommunication Management Network
TOPI Timing Output Physical Interface
TR1ES Threshold 1 for Errored Second counting
TR1SES Threshold 1 for Severely Errored Second counting
TR2ES Threshold 2 for Errored Second counting
TR2SES Threshold 2 for Severely Errored Second counting
TS Time Slot
TS0 FAS Time Slot 0 with Frame Alignment Signal
TS0 NFAS Time Slot 0 without Frame Alignment Signal
TS16 Time Slot 16
TX/RX Transmit/Receive
UP Unacceptable Performance
UT Unavailable Time
WS Work Station
XC Cross Connect
XCTS Cross Connect Timing Source
NOTE: Abbreviations used in subclause 7.3 are listed in subclause 7.3.1.0.
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ETS 300 010-2: March 1997
4 DXC management network
Characterization of a Digital Cross Connect (DXC) equipment management network is derived from ITU-T
Recommendation G.784 [13], especially figure 1 of that document. Figure 1 below reproduces a similar
organization for the management view of management network where an Embedded Operation Channel
EOC replaces the specific Synchronous Digital Hierarchy (SDH) Embedded Control Channel (ECC). This
figure relates only to functional aspects and does not imply implementation or routeing facilities. EOC
could be either supported by a particular 64 kbit/s Time Slot (TS) or by one or some of the Sa bits of the
CCITT Recommendation G.704 [2] frame Network Elements (NE) could be directly connected with a
Mediation Device (MD) or via other devices, including NEs.
NOTE: Network operators may be required to provide duplication of the management
interface.
OSF
OS
NETWORK
Q/EOC
VIEW
TMN
FUNCTIONS
SERVICES
MF
MD
Q/EOC Q/EOC
Q/EOC
NEF NEF
QAF
NE
Network
DXC
element
m reference point
DXC
MD Mediation Device
MF Mediation Function
NEF Network Element Function
QAF Q Adapter Function
OS Operations System
OSF Operations System Function
TMN Telecommunications Management Network
Figure 1: Functional view of management network
5 Information model
There is no information model in this edition of the ETS.
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ETS 300 010-2: March 1997
6 Management interfaces
The DXC shall be able to terminate and generate the cross connect management control channel(s). For
this purpose, the DXC should present, according to ITU-T Recommendation M.3010 [8], the following
interfaces:
Q-interface: This interface provides a management control channel between the Operations System (OS)
and the DXC. Depending on the management network implementation, it could be a Qx or a Q3 interface.
There are no protocol suites in this edition of the ETS.
If this interface is not provided, an interface supporting an m-reference point shall be provided.
F-interface: This optional interface provides Work Station (WS) access to the OS via the DXC.
m-reference point: This is supported by a proprietary interface and allows, via an external Q Adaptation
Function (QAF), a management connection between an OS conforming to TMN recommendations and a
DXC that does not conform to TMN recommendations.
Additionally, the DXC shall provide a Local Control (LC) interface for local attachment of a proprietary
management entity. This interface is concerned with:
- installation and maintenance (with changes of the DXC-configuration), in cases where the
connection to the OS is interrupted or voluntarily blocked;
- local monitoring of the DXC status (without changes of the DXC-configuration).
NOTE: For the first case, means should be implemented in the DXC and/or the OS to
overcome conflict/misalignment situations between the DXC configuration locally
induced via the LC interface and the DXC configuration as it is stored in the OS
database.
7 Applications functions
7.1 Fault management
7.1.1 Alarm surveillance
7.1.1.1 Principle
Alarm surveillance is concerned with the detection and reporting of relevant events/conditions which occur
in the equipment or which are detected at equipment level. Events/conditions detected within the
equipment and in the incoming signals shall be reportable. Alarms are indications that are automatically
generated by the equipment or NE as the result of certain events/conditions and associated processing.
The user shall have the ability to define which events/conditions generate autonomous reports. The
remaining events/conditions are reportable on request.
The relevant events/conditions are derived from the Defect or Failure Conditions (DFC) given in
ETS 300 010-1 [14]. The processing associated with the occurrence of DFC is described in figure 2.
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ETS 300 010-2: March 1997
Performance
Internal
Defect
Time
notification
Processing
or
filtering
filtering
Failure
Q/F/m/LC
(Configure)
Notification
Q/F/m/LC
module
(Notifications)
Maintenance
Q/F/m/LC
log
Q/F/m/LC
(Request)
NOTE 1: TMN requires a notification function: this may be supported either by the equipment itself or by
a QAF function.
NOTE 2: The "configure" arrow is shown according to the text of subclause 7.1.1.1. This representation
does not preclude that the filtering module, internal notification module and processing module
are also configurable.
Figure 2: Alarm related maintenance functions
Functions associated with the various functional blocks to figure 2 are as follows:
defect or failure: This functional block performs the elementary functions necessary for the detection of
any of the defect or failure conditions specified in ETS 300 010-1 [14] or in this ETS.
time filtering: This functional block provides optional programmable time filtering, ranging from 0 to 10 s
in steps of 1 s, which allows notification of a selected defect or failure condition only if its duration is
greater than the predetermined value.
Internal notification
filtering: This functional block manages the sending of notifications (occurrence, disappearance of DFC)
to the appropriate functional block. It also enables/disables discrimination of a given DFC depending upon
its nature and if necessary, to forward it to appropriate functional blocks.
processing: This function receives the various notifications, gathers them and performs the necessary
correlation in such a way that no redundant information will be needed. In addition, this function may allow
provision of a diagnostic for the occurrence of a DFC. The processing functional block also generates
synthetic notifications destined for the Equipment Management Function.
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ETS 300 010-2: March 1997
Notification
module: This functional block is under the control of the user who may determine the notifications
required to be spontaneously transmitted to the Q/F/m interface/reference point. Also included is
programmable notification filtering in the range of 0 s to 60 s in steps of 10 s.
Maintenance
log: This functional block registers all the DFCs occurring in the DXC in an allotted memory area. A
stored DFC should include: nature (i.e. LOS, LFA, etc.), type, managed function, time (occurrence,
clearing). The user shall have the ability to request transmission or display of stored information according
to criteria which are described in subclause 7.1.1.2.
7.1.1.2 Alarm-related functions
The following alarm-related functions may be required to be supported at the equipment level:
- report autonomous alarms;
- request all alarms;
- report all alarms;
- allow/inhibit alarm reporting over any EOC;
- request status of allow/inhibit alarm reporting;
- report status of allow/inhibit alarm reporting.
The following table 1 contains the minimum list of alarm conditions (default values) described in
subclause 7.1.2.
Table 1: Alarm conditions
Alarm type Alarm condition Mandatory/ Perceived
optional severity
level
Communication LOS 2 048U M Major
EXBER O Pending
LOS 2 048S M Critical
LOF M Critical
EXBER O Minor
RAI M Minor
AIS M Minor
LMFA M Minor
RMAI (note) M Minor
AIS TS16 M Minor
Management link failure O Critical
LSYNC M Major
Equipment 2MB Port M Major
Power supply M Critical
Cross Connection function M Critical
Common logic M Major
Special functions M Major
Processing Misalignment database M Major
Time management O Minor
Alarm memory M Minor
Downloading software error O Major
Software corrupting M Major
Quality of service Degraded performance (DP) O Minor
Unacceptable performance (UP) O Major
NOTE: Remote Multiframe Alarm Indication (RMAI): this alarm corresponds to the Remote
Alarm Indication (RAI) in time slot 16.
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ETS 300 010-2: March 1997
7.1.2 Alarm classification
Alarms should be classified using the alarm type categories and perceived severity defined in ITU-T
Recommendation X.733 [12].
7.1.2.1 Alarm type
Five basic categories of alarms are specified. These are given in the following subclauses.
7.1.2.1.1 Communications alarm
This type of alarm includes the following defect or failure conditions which are shown with the related
functional part of the 64 (or n x 64) kbit/s digital cross connect equipment.
- 2 048 kbit/s unstructured;
- loss of incoming signal;
- excessive error ratio (bipolar coding violations) (see note).
- 2 048 kbit/s structured access port carrying signals with channel associated signalling;
- loss of incoming signal (see subclause 11.1.1.2 of ETS 300 010-1 [14]);
- loss of frame alignment (see subclause 10.1 of ETS 300 010-1 [14]);
- excessive error ratio;
- defect indication from remote end (bit3 and any additional spare bit of Time Slot 0 without
Frame Alignment Signal (TS0 NFAS));
- 2 048 kbit/s Alarm Indication Signal (AIS) received (see subclause 11.1.1.5 of
ETS 300 010-1 [14]);
- loss of multiframe alignment (bit 6 in TS16) (see subclause A.11.1.1.7 of
ETS 300 010-1 [14]);
- defect indication from remote end (see subclause A.11.1.1.9 of ETS 300 010-1 [14]);
- AIS received in TS16 (see subclause A.11.1.1.8 of ETS 300 010-1 [14]).
The notification of each alarm shall be in accordance with the filtering values defined in the
subclause 7.1.1.1.
NOTE: The detection of this alarm is optional.
- Management links.
Alarm indicating failure in management link(s), if appropriate.
- Synchronization interface(s).
Loss of synchronization signal (see subclause 11.2.1.2 of ETS 300 010-1 [14]).
7.1.2.1.2 Equipment alarms
This type of alarm includes at least the following defect or failure conditions:
Failure of a 2 048 kbit/s port
The 2 Mbit/s port (Physical Interface (PI) and Plesiochronous Path Termination (PPT) functions) shall be
provided with an appropriate check procedure to detect at least the following defect/failure conditions on
2 Mbit/s port:
- TX/RX circuits, included the elastic stores;
- loss of internal timing signals from Cross Connect Timing Source (XCTS) function;
- loss of internal power feed;
- internal communication interface with common logic;
- internal interface with cross-connection function.
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ETS 300 010-2: March 1997
Power failure
This alarm shall be activated either by absence of the external power supply or a fault in the single DXC
power supply unit.
Connection failure
The cross-connection function shall be provided with appropriate check procedures to detect defect/failure
conditions on a 64 or n x 64 kbit/s connection. The DXC control system shall be able to indicate the part or
unit of the DXC that caused the connection failure.
Timing failure
The XCTS function shall be provided with an appropriate check procedure to detect the loss of T1 signal
(and/or T4 signal if required).
Common logic failure
The DXC shall be provided with appropriate check procedure to detect at least:
- defect/failure of the CPUs;
- defect of the program memory;
- defect of the data memory;
- loss of the internal power feeding.
Special function failure
Each different special function implemented in the DXC shall be provided with appropriate check
procedures to detect defect/failure conditions of its functionalities. More details will be given along with the
definition of the individual function.
7.1.2.1.3 Processing alarm
This type of alarm includes, where applicable, the following defect or failure conditions:
- time management;
- alarm memory (overflow);
- down loading software error;
- software corruption;
- misalignment of the data-base.
7.1.2.1.4 Environmental alarm
No particular environmental alarms are requested.
7.1.2.2 Perceived severity level
There are seven severity levels defined in ITU-T Recommendation X.733 [12] providing an indication of
how it is perceived that the capability of the managed object has been affected.
The levels to be used in this context are listed and defined hereafter:
- Cleared:
This level indicates the clearing of one or more previously reported alarms;
- Indeterminate:
This level indicates that the severity level of the service affecting condition cannot be determined;
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ETS 300 010-2: March 1997
- Critical:
This level indicates that a service affecting condition occurred and that immediate remedial action is
required;
- Major:
This level indicates that a service affecting condition occurred and that an urgent correction action
is required;
- Minor:
This level indicates the existence of a non-service affecting condition and that the correction action
should be taken in order to prevent a more serious condition (e.g. a service affecting condition);
- Warning:
This level indicates the detection of a potential or impeding service affecting condition, before any
significant effect has been felt;
- Pending:
This level indicates that some alarm condition has been recognized but has not persisted long
enough to qualify as a non-transient condition (as determined by some algorithm applied to the
alarm condition). This does not directly cause any alarm notification.
The equipment can provide part of these seven severity levels but not necessarily all of them.
7.1.2.3 Alarm record
The 64 (or n x 64) kbit/s cross connect equipment and its (local) management system shall provide an
alarm record. An alarm record represents information stored in logs.
Each record should include at least the following parameters:
- managed functions;
- alarm type;
- perceived severity;
- probable cause;
- event time.
Optionally the record should include the "backed-up status" parameter. This parameter indicates whether
or not the failed object has been backed up.
7.1.3 Test functions
7.1.3.1 Loopbacks
7.1.3.1.1 Loopbacks at the 2 048 kbit/s level
Referring to figure 2 of ETS 300 010-1 [14], at reference point G, the equipment shall provide local (2MI)
or remote (2ME) loopbacks for the purpose of transmission section testing. The description of these two
loopbacks is given in figure 3.
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ETS 300 010-2: March 1997
G1b
G1a
Plesiochronous
Physical
Low Order Path
Interface
2ME 2MI
Termination
(PI)
(PLPT)
G2b G2a
NOTE: G1b = G2b G1a = G2a
G1a = 2 048 kbp/s Alarm Indication Signal (AIS) G2b = AIS
G2a ignore G2b G1a ignore G1b
Figure 3: Test functions for 2 048 kbit/s access port
The provision of 2 048 kbp/s External (remote) Loopback (2ME) is mandatory while the 2 048 kbp/s
Internal (local) Loopback (2MI) is an option for the equipment depending on the telecommunications
organization maintenance strategy.
NOTE: Provision needs to be made to avoid activation of 2 048 kbit/s loopback when the
corresponding 2 Mbit/s signal is carrying the active EOC (when used).
Upon request from a management interface, the equipment shall provide all information about the active
loopbacks.
7.1.3.1.2 n x 64 kbit/s dropping function
The equipment shall provide an n x 64 kbit/s logical dropping function for test purposes for any selected
n x 64 kbit/s (n=1 to 31) connection set in the equipment. This function shall be activated (or deactivated)
under management system control.
Two different applications of this feature for testing n x 64 kbit/s channels are possible. One is a
monitoring function (figure 4a) where data signals of both directions are broadcasted towards one or more
2 048 kbit/s access port(s), depending on the number of channels to be tested. The second test is
realized in a split mode (figure 4b) where internal cross connections are set down and the two legs of the
communication channels are derived towards one or more 2 048 kbit/s access port(s), depending on the
number of channels to be tested.
At the end of the test the previous connections shall be restored.
a) b)
D X C D X C
2 048 kbit/s Access port
Internal n x 64 kbit/s connection
2 048 Kbit/s access port (for test purposes)
Figure 4: Description of n x 64 kbit/s dropping functions
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ETS 300 010-2: March 1997
7.1.3.1.3 Internal n x 64 kbit/s loopback
The equipment shall provide internal n x 64 kbit/s logical loopback for test purposes for any selected
n x 64 kbit/s channel cross connected in the equipment. This function shall be activated (or deactivated)
under management system control. Figure 5 shows the principle for n x 64 kbit/s loopback.
G1/A1 J1 J'1 G'1/A'1
G2/A2 J2 J'2 G'2/A'2
n x 64 kbit/s loopback
Figure 5: Principle for n x 64 kbit/s loopback
7.1.3.1.4 Loopback characteristics
For all loopbacks described in subclauses 7.1.3.1 to 7.1.3.3, the solution presented in figure 6 shall be
applied.
AIS
Figure 6: Type of loopback
7.1.3.1.5 Internal tests
It is considered that a monitoring function for essential parts of the 64 (or n x 64) kbit/s cross connect
equipment should be provided. The parts which are concerned are:
- cross connection matrix (or equivalent);
- timing signals;
- power feed;
- common logic;
- line card;
- TMN interfaces.
7.2 Performance management
The following subclauses refer to the quality of service monitoring in 2 048 kbit/s (CCITT
Recommendation G.704 [2]) paths using the Cyclic Redundancy Check procedure-4 (CRC4). Other
methods for 2 048 kbit/s (CCITT Recommendation G.704 [2]) signals performance measurement may be
implemented irrespective of whether they use the CRC4 procedure.
Performance management is an application function for the management of the 64 kbit/s cross connect
equipment. It applies to the 2 048 kbit/s digital path level. It involves some computing functions on
Anomaly Events (AE) or Defect Events (DE) which are listed later in this subclause. This function covers
two different requirements related respectively to long term or short term performance evaluation.
The long term performance evaluation provides results according to ITU-T Recommendation G.826 [3].
For the DXC application this is applicable to 2 048 kbit/s CCITT Recommendation G.704 [2] structured
digital paths.
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ETS 300 010-2: March 1997
The short term performance evaluation follows the principles described in ITU-T Recommendations
M.20 [4], M.2100 [5], M.2110 [6] and M.2120 [7]. This is to be provided to cover at least the second of the
two following situations where the equipment is involved:
- bringing-into-service a 2 048 kbit/s digital path (note);
- maintenance of a 2 048 kbit/s digital path in service.
NOTE: Alternatively, a Pseudo Random Bit Sequence (PRBS) generator and analyser
according to ITU-T Recommendation O.151 [10] may be used for performance
evaluation in the bringing-into-service situation.
7.2.1 Long term performance evaluation
The long term performance evaluation for CCITT Recommendation G.704 [2] framed 2 048 kbit/s signals
is based on ITU-T Recommendation G.826 [3]. For this evaluation, the following parameters are
considered and corresponding definitions are given in subclause 7.2.4:
- Errored Block (EB);
- Errored Second (ES);
- Severely Errored Second (SES);
- Background Block Error (BBE).
The associated computing functions are limited to the calculation of current ratio for ES, SES and BBE
parameters and identified as:
- Errored Second Ratio (ESR);
- Severely Errored second Ratio (SER);
- Background Block Error Ratio (BBER).
The accumulation of performance parameters and associated ratio calculation should be made on a long
term basis (e.g. 3 months or more). This does not preclude intermediate evaluation under request of the
operation system but this is not considered a mandatory function. Comparison of the long term
performance evaluation with the performance allocated to a given 2 048 kbit/s digital path and to the
specified limits for ESR, SER and BBER are not considered as a management function for the flexible
multiplexer.
Figure 11 depicts corresponding long term performance evaluation functions.
7.2.2 Short term performance evaluation
The associated computing function requires four levels of analysis. The first one concerns the detection of
elementary events which are necessary for the performance management. The second level realizes a
statistical calculation based on a one second time period in order to classify each second as Normal, as
an Errored Second (ES) or as a Severely Errored Second (SES). A notification module subsequently
provides the necessary information to the fourth level where the corresponding quality of service is
determined, individually per 2 048 kbit/s access port and for the received signal (optionally for the
transmitted signal). The performance evaluation is only applicable for the period of time when the digital
path is available.
7.2.2.1 Elementary events for in-service measurement
Elementary events affecting the performance of 2 048 kbit/s digital paths are classified into Anomaly
Events (AE) or Defect Events (DE) according to ITU-T Recommendation M.20 [4].
7.2.2.1.1 Anomaly event, receive part
The following events shall be detected:
- Block Error (BE): CRC4 code word violation (errored CRC4 block).
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ETS 300 010-2: March 1997
7.2.2.1.2 Anomaly event, transmit part
The following event shall be detected:
- reception of E bit.
7.2.2.1.3 Defect events, receive part
The following events shall be detected:
- Loss of Frame (LOF) alignment;
- Loss of Signal (LOS).
7.2.2.1.4 Defect events, transmit part
The following event shall be detected:
- bit 3 of TS0 NFAS.
7.2.2.2 Elementary events for out-of-service measurement
The usefulness of having a test function inside the DXC able to generate/analyse a PRBS for the purpose
of out-of-service performance measurement depends on the maintenance strategy of the operator. When
providing this function, the equipment is able to generate unframed 2 048 kbit/s, framed 31 x 64 kbit/s (or
30 x 64 kbit/s in case of 2 048 kbit/s signals carrying channel associated signalling) PRBS signals at the
level of a number of 2 048 kbit/s access ports.
The out-of-service performance measurement concerns either a bringing-into-service situation or a test
process following a failure condition and repair in a point-to-point configuration or on a remote 2ME
loopback (refer to subclause 7.1.3.1.1).
7.2.3 Condition of measurement
The final performance evaluation shall only be processed when the 2 048 kbit/s digital path is in the
available time, i.e. disabled when determined in unavailable time.
Definition of unavailable time:
Unavailable Time (UT) for a 2 048 kbit/s digital path starts at the outset of 10 consecutive SES as shown
in figure 7. A 2 048 kbit/s digital path is in a period of unavailable time if one or both directions are in the
unavailable state.
1 se co nd
ES
SES
UNAVAILABLE TIM E
Perform an ce m onitoring activated
Figure 7: Definition of unavailable time
The criterion to determine if one particular second is a SES is given in table 2.
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ETS 300 010-2: March 1997
7.2.4 Performance parameters evaluation
In addition to the detection of AE and DE events (first level of the performance evaluation), the equipment
shall be able to provide in-service performance parameters as shown in table 2.
The in-service performance parameters to be considered for a 2 048 kbit/s digital path using the CRC4
procedure are given in table 2.
Table 2: In-service performance parameters with CRC4
Path level POH available AE/DE per second Interpretation Interpretation
to derive for for
AE/DE data receive transmit
direction direction
ES + SES
≥ 1 LOF
≥1 LORS ES + SES
≥ 1 CRC4 error(s) ES
CRC4 ES + SES
≥ 805 CRC4 errors
E-bit ES
≥ 1 E-bit
2 048 kbit/s FAS ES + SES
≥ 830 E-bit
CRC4 A-bit ES
≥ 1 A-bit
San-bit ≥ 1 San-bit ES
≥ D1 A-bit ES + SES
7.2.5 Performance process
The ES and SES are counted individually in two counters C1 and C2 for the 15 minute basis evaluation
process and in two counters C3 and C4 for the 24 hour basis evaluation process.
7.2.5.1 15 minute process
ES and SES performance parameters are transmitted to the two counters C1 and C2 as indicated in
figure 8. These two counters are reset at the outset of every 15 minute calculation period. TR1ES and
TR1SES thresholds are associated with counters C1 and C2 respectively. Figure 9 depicts the calculation
mechanism of the number of received performance parameters and consequent actions within each
15 minute period.
ES ES SES SES ES
C1
ES COUNTER
C2
SES COUNTER
Figure 8: Counting of performance parameters
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ETS 300 010-2: March 1997
TR1ES,date,tim e TR1SES,date,tim e
report report
C1>=TR1ES
Continue to count
C1>=TR1SES
log registers
15 m inutes
reset C1 & C2
Figure 9: Consequent actions
The two options allowed for the 15 minute evaluation process are described next.
7.2.5.1.1 Option 1 - evaluation without hysteresis
When the content of counter C1 or counter C2 exceeds the thresholds TR1ES or TR1SES respectively in
a given 15 minute period, a time and date stamped report is sent. The two counters continue to count the
received ES or SES performance parameters. At the beginning of every 15 minute period, reports
including the content of the two counters C1 and C2 are sent to the log file. This is shown in figure 10.
15 m inutes
log reports
TR1ES TR1SES TR1ES
TR1SES date, time, report
Figure 10: Performance evaluation process without hysteresis
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ETS 300 010-2: March 1997
7.2.5.1.2 Option 2 - Evaluation with hysteresis
The ES counter (C1) has two thresholds TR1ES and W, with W not greater than TR1ES. The SES
counter (C2) has two thresholds TR1SES and 0.
When the content of C1 exceeds TR1ES within a period of 15 minutes, a TR1ES date and time stamped
report is sent. There is no additional report sent during the following 15 minute periods until a 15 minute
period with content of C1 no
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