ETSI ETS 300 010-1 ed.2 (1995-05)

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 1: Core functions and characteristics

RE/TM-01014-2

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 – 1. del: Jedrne funkcije in karakteristike

General Information

• Status: Published
• Publication Date: 15-May-1995
• Technical Committee: TM 1 - TM Core networks, fibres and cables
• Current Stage: 12 - Completion
• Due Date: 01-Mar-1995
• Completion Date: 16-May-1995
• Ref Project: SIST ETS 300 010-1 E2:2003 - 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 1: Core functions and characteristics

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 – 1. del: Jedrne
funkcije in karakteristike
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 1: Core functions
and characteristics
Ta slovenski standard je istoveten z: ETS 300 010-1 Edition 2
ICS:
33.040.20 Prenosni sistem Transmission systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN ETS 300 010-1
TELECOMMUNICATION May 1995
STANDARD Second Edition
Source: ETSI TC-TM Reference: RE/TM-01014-2
ICS: 33.040.40
Transmission, multiplexing
Key words:
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
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
F-06921 Sophia Antipolis CEDEX - FRANCE
Postal address:
650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
Office address:
c=fr, a=atlas, p=etsi, s=secretariat - [e-mail]
X.400: Internet:
Tel.: [phone] - Fax: [phone]
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 1995. All rights reserved.
New presentation - see History box

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ETS 300 010-1: May 1995
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 300 010-1: May 1995
Contents
Foreword .7
1 Scope .9
2 Normative references.9
3 Definitions.10
4 Symbols and abbreviations .11
5 Network reference configuration .11
6 Reference model.12
7 General characteristics .14
7.1 Size .14
7.2 Timing signal.14
7.2.1 Control of timing signal.14
7.2.2 Timing performance .14
8 Functions.14
8.1 Cross connection .14
8.2 Management.14
9 Interfaces.15
9.1 2 048 kbit/s interface.15
9.1.1 Physical interface .15
9.1.2 Frame structure.15
9.2 Synchronization interface at 2 048 kHz .15
9.3 Interface with the TMN.15
9.4 User interface .15
9.5 Power supply interface.15
10 Frame alignment and CRC procedure .15
10.1 Loss of frame alignment .15
10.2 Recovery of frame alignment.15
10.3 CRC multiframe alignment in TS 0 .15
10.4 CRC bit monitoring.15
11 Defect or failure conditions and performance monitoring .16
11.1 Defect or failure conditions at the G2 (or A2) reference point and consequent actions
at the J2 (or G2) and G1 (or A1) reference points.16
11.1.1 Defect or failure condition.16
11.1.1.1 Failure of power supply.16
11.1.1.2 Loss of incoming signal at 2 048 kbit/s.16
11.1.1.3 Loss of frame alignment .16
-3
11.1.1.4 Error ratio 1:10 .16
11.1.1.5 Reception of Alarm Indication Signal (AIS) .16
11.1.1.6 Defect indication from a remote equipment.16
11.1.2 Consequent actions.17
11.2 Defect or failure conditions and consequent actions for the core of the equipment.18
11.2.1 Defect or failure conditions.18
11.2.1.1 Failure of a connection .18
11.2.1.2 Loss of synchronization signal(s).18
11.2.2 Consequent actions.18
11.3 Performance monitoring .18

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ETS 300 010-1: May 1995
12 Performance . 19
12.1 Blocking factor. 19
12.2 Jitter. 19
12.2.1 Jitter at 2 048 kbit/s output. 19
12.2.2 Jitter tolerance at 2 048 kbit/s input. 19
12.2.3 Jitter transfer function . 19
12.3 Transfer delay . 20
12.4 Slips. 20
12.5 Error characteristics of the equipment . 20
Annex A (normative): Additional requirements for cross connection of channel associated signalling
bits in TS 16. 21
A.1 Network reference configuration (clause 5). 21
A.2 Cross connection (subclause 8.1) . 21
A.3 Frame structure (subclause 9.1.2). 21
A.4 Defect or failure conditions and performance monitoring (clause 11). 22
A.4.1 Defect or failure conditions (subclause 11.1.1). 22
A.4.1.1 Loss of multiframe alignment. 22
A.4.1.2 Reception of AIS in TS 16 . 22
A.4.1.3 Defect indication in TS 16 from a remote equipment . 22
A.4.2 Consequent actions (subclause 11.1.2). 23
A.4.3 Defect or failure conditions and consequent actions for the core of the equipment
(subclause 11.2). 24
A.4.3.1 Failure of a connection (subclause 11.2.1.1). 24
A.4.3.2 Consequent actions (subclause 11.2.2) . 24
A.5 Transfer delay (subclause 12.3) . 24
A.5.1 64 and n x 64 kbit/s signals. 24
A.5.2 Channel associated signalling in TS 16 . 24
Annex B (normative): Additional TS allocation . 25
B.1 Cross connection (subclause 8.1) . 25
B.2 Frame structure (subclause 9.1.2). 25
Annex C (normative): Other timing and slip performance requirements . 26
C.1 More stringent performance . 26
C.1.1 Timing performance (subclause 7.2.2) . 26
C.2 Less stringent performance. 26
C.2.1 Timing performance (subclause 7.2.2) . 26
C.2.2 Slips (subclause 12.4). 26
Annex D (normative): Additional requirements for cross connection. 27
D.1 Additional requirements for cross connection of unstructured signal 2 048 kbit/s signal . 27
D.1.1 Function. 27
D.1.2 Characteristics . 27
D.1.2.1 Type of cross connection. 27
D.1.2.2 Framing structure . 27
D.1.2.3 Bit sequence independence . 27
D.1.3 Performance. 27
D.1.3.1 Blocking . 27
D.1.3.2 Integrity . 27
D.1.3.3 Transfer delay. 27
D.1.3.4 Slips . 27
D.1.4 Defect or failure conditions and consequent actions. 27

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ETS 300 010-1: May 1995
D.1.4.1 Defect or failure conditions at the A2 reference point .27
D.1.4.1.1 Loss of incoming 2 048 kbit/s signal.28
D.1.4.1.2 Line code violation .29
D.1.4.2 Defect or failure conditions in the core equipment .29
D.1.4.2.1 Consequent actions.30
D.2 Additional requirements for cross connection of CCITT Recommendation G.704 framed
2 048 kbit/s signal.30
D.2.1 Function .30
D.2.2 Characteristics .31
D.2.2.1 Type of cross connection .31
D.2.2.2 CRC 4 procedure .31
D.2.2.3 Far end defect or failure indication.31
D.2.2.3.1 TS 0 NFAS.31
D.2.2.3.2 Bit 6 TS 16 fr0.31
D.2.3 Performance .31
D.2.3.1 Blocking.31
D.2.3.2 Integrity.31
D.2.3.3 Transfer delay .31
D.2.4 Defect or failure conditions and consequent actions .32
D.3 Additional requirements for TS 0 cross connection.32
D.3.1 Function .32
D.3.2 Characteristics .32
D.3.2.1 Type of cross connection .32
D.3.2.2 Transformation/substitution of Frame Alignment Signal (FAS).32
D.3.2.3 TS allocation.32
D.3.2.4 CRC 4 procedure .33
D.3.2.5 Far end defect or failure indication.33
D.3.3 Defect or failure conditions and consequent actions .33
D.3.3.1 Access port i.33
D.3.3.2 Access port j.33
D.3.4 Performance .34
D.3.4.1 Blocking.34
D.3.4.2 Transfer delay .34
D.3.4.3 Integrity.34
Annex E (informative): Bibliography.35
History.36

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ETS 300 010-1: May 1995
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ETS 300 010-1: May 1995
Foreword
This second edition European Telecommunication Standard (ETS) has been produced by the
Transmission and Multiplexing (TM) Technical Committee of the European Telecommunications
Standards Institute (ETSI).
This ETS has been produced 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.
This ETS consists of 2 parts as follows:
Part 1: "Core functions and characteristics".
Part 2: "Management" (DE/TM-01014-3).
NOTE: Part 2 of this ETS (ETS 300 010-2) is under development within ETSI TC-TM.
The corresponding ETS for equipment for cross connection of sub-rate signals is under development.
Proposed transposition dates
Date of latest announcement of this ETS (doa): 31 August 1995
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 31 August 1995
Date of withdrawal of any conflicting National Standard (dow): 29 February 1996

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ETS 300 010-1: May 1995
1 Scope
This European Telecommunication Standard (ETS) describes requirements of cross connect equipment
for use in synchronous digital leased line networks. It covers equipment having 2 048 kbit/s access ports
and is limited to the basic functions, external characteristics and performance of the equipment.
Requirements for the management of the equipment are to be covered in ETS 300 010-2 which should be
used in conjunction with this part of the ETS.
NOTE: ETS 300 010-2 is under development within ETSI TC-TM.
Some network operators may have additional requirements and these are provided in normative annexes
A to C.
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 to applies.
[1] CCITT Recommendation G.703 (1991): "Physical/electrical characteristics of
hierarchical digital interfaces".
[2] CCITT Recommendation G.704 (1988): "Synchronous frame structures used at
primary and secondary hierarchical levels".
[3] CCITT Recommendation G.706 (1991): "Frame alignment and cyclic
redundancy check (CRC) procedures relating to basic frame structures defined
in CCITT Recommendation G.704".
[4] CCITT Recommendation G.732 (1991): "Characteristics of primary PCM
multiplex equipment operating at 2 048 kbit/s".
[5] CCITT Recommendation G.735 (1988): "Characteristics of primary PCM
multiplex equipment operating at 2 048 kbit/s and offering synchronous digital
access at 384 and/or 64 kbit/s".
[6] CCITT Recommendation G.736 (1988): "Characteristics of a synchronous digital
multiplex equipment operating at 2 048 kbit/s".
[7] CCITT Recommendation G.773 (1988): "Protocol suites for Q interface for
management of transmission systems".
[8] CCITT Recommendation G.811 (1988): "Timing requirements at the outputs of
primary reference clocks suitable for plesiochronous operation of international
digital links".
[9] CCITT Recommendation G.812 (1988): "Timing requirements at the outputs of
slave clocks suitable for plesiochronous operation of international digital links".
[10] CCITT Recommendation G.822 (1988): "Controlled slip rate objectives on an
international digital connection".
[11] CCITT Recommendation G.823 (1988): "The control of jitter and wander within
digital networks which are based on the 2 048 kbit/s hierarchy".
[12] CCITT Recommendation M.20 (1988): "Maintenance philosophy for
telecommunication networks".
[13] CCITT Recommendation M.2100 (1992): "Performance limits for bringing into
service and maintenance of digital paths, sections and line sections".

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ETS 300 010-1: May 1995
[14] CCITT Recommendation M.3010 (1988): "Principles for a telecommunication
management network".
[15] CCITT Recommendation O.162: "Specifications for an instrument to monitor the
frame alignment signal of frame structures (frame alignment signal monitor)".
[16] CEPT Recommendation T/TR 02-02, edition 3 (1987): "Rack/telecommunication
centre power supply interfaces".
NOTE: This CEPT Recommendation is to be replaced by prETS 300 132 ("Equipment
Engineering (EE); Power supply interface at the input to the telecommunications
equipments (DE/EE-2001)") when available.
3 Definitions
For the purposes of this ETS, the following definitions apply.
synchronous cross connect equipment: A device which accepts a number of signals comprising
synchronously multiplexed lower bit rate signals and cross connects the constituent lower bit rate signals.
blocking factor: The existence of cross connections in a cross connect equipment can block the
establishing of any new cross connection. The blocking factor is the probability that a new cross
connection cannot be made, expressed as a decimal fraction of 1.
synchronization signal: A clock control signal obtained from a synchronization network.
access port: Access ports of a cross connect equipment are input and output ports used to terminate
2 048 kbit/s signals transporting synchronous 64 and n x 64 kbit/s signals to be cross connected.
cross connection capacity: This comprises the maximum number of equivalent channels at 64 kbit/s
which can be cross connected as equivalent to a 64 kbit/s channel.
NOTE: Cross connection of Time Slot 0 (TS 0) (or bits 1 to 8) or Time Slot 16 (TS 16)
information according to CCITT Recommendation G.704 [2] should be considered as
equivalent to a 64 kbit/s channel.

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ETS 300 010-1: May 1995
4 Symbols and abbreviations
For the purposes of this ETS, the following symbols and abbreviations apply.
AIS Alarm Indication Signal
CRC Cyclic Redundancy Check
CRC 4 Cyclic Redundancy Check procedure relating to the 2 048 kbit/s basic frame
structure according to CCITT Recommendation G.704 [2]
EFS Error Free Second
FAS Frame Alignment Signal
fr0 frame 0
LOS Loss Of incoming 2 048 kbit/s Signal
SES Severely Errored Second
TMN Telecommunication Management Network
TS Time Slot
TS 0 Time Slot 0
TS 16 Time Slot 16
TS 0 NFAS Time Slot 0 without Frame Alignment Signal
5 Network reference configuration
Figure 1 gives typical representation of the cross connect equipment in its network environment.
Synchronous cross connect equipment
Multiplexer equipment, e.g. according to CCITT Recommendation G.736 [6]
2 048 kbit/s interface
Figure 1: Network reference configuration

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ETS 300 010-1: May 1995
6 Reference model
Figure 2 provides a reference model for the equipment, including the location of reference points.
Definitions of functional blocks are given below:
physical interface (PI): This function terminates and generates the signals at an access port. This
function also detects the Loss Of incoming 2 048 kbit/s Signal (LOS) condition, the line code violations as
appropriate.
plesiochronous path termination (PPT): This function terminates and generates a logical signal at
2 048 kbit/s at an access port. This function provides frame generation and recovery and detection of
defect or failure conditions on the 2 048 kbit/s logical signal.
cross connection function (XC): This function allows the cross connection of 64 and n x 64 kbit/s (n
ranging from 1 to 32) signals from J1 reference point of an access port i to J2 reference point of an other
access port j and from J1 reference point of this access port j to J2 reference point of access port i (see
Note 4 under Figure 2 for the meaning of J1 and J2 reference points).
channel associated signalling cross connection function (CASXC): If channel associated signalling is
used then this function provides the cross connection of the a, b, c and d signalling information from L1 to
L2 reference points in correspondence with the related 64 or n x 64 kbit/s cross connection from J1
reference point of an access port i to J2 reference point of an other access port j and from J1 reference
point of this access port j to J2 reference point of access port i assuming that access ports i and j are
carrying signals containing channel associated signalling (see Note 5 under Figure 2 for the meaning of L1
and L2 reference points).
special function (SF): Example of optional special function are analogue multipoint conference bridge,
data multipoint bridge, broadcasting, digital low bit rate transcoding for voice channel.
timing input physical interface (TIPI): This function terminates an external 2 048 kHz synchronization
signal.
timing output physical interface (TOPI): This function generates an external 2 048 kHz signal.
cross connect timing source (XCTS): This function provides all internal timing signals necessary for the
cross connect equipment.
equipment management function (EMF): This function is connected to all the other functional blocks
and provides for a local user or the Telecommunication Management Network (TMN) a mean to perform
all the management functions of the cross connect equipment.
message communication function (MCF): This function terminates and generates the cross connect
management control channel(s). The control channel may as well be a Q interface. The function is also
able to inter work as a relay function between the local workstation connected via a F interface and the
TMN. It also provides local access to internal management functions via a m interface which is not subject
to standardization.
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ETS 300 010-1: May 1995
A
ETS 300 010-1
PI
S1
G
S2
T2
PPT
TI
TIPI
U1
J
SF XC
CASXC
L
K TO
TOPI
S5
S4
U2
S3
T5 T4
T1
XCTS
T2
S6
S7
S8
S1
EMF
S5
V
F
U1
MCF
U2
m
Q
ETS 300 010-2
NOTE 1: T1 is distributed to all the others functional blocks.
NOTE 2: Not all functional blocks are always required.
NOTE 3: Not all the necessary functions are shown; e.g. internal code conversion or line
protection.
NOTE 4: Reference points A to J can each be divided into two reference points (e.g. A1 and A2)
which relate to the J to A (direction 2 on the figure) and A to J (direction 1 on the
figure) directions respectively.
NOTE 5: In the same way, reference points K and L can each be divided into two reference
points (K1, K2 and L1, L2 respectively).
NOTE 6: The functional reference model and the defined reference points are only for the
purpose of describing the functions of the cross connect equipment and are not
intended to represent actual implementations. References to signalling bits or
information, 64 kbit/s time slots or frame structures at internal reference points J, K
and L refer only to the logical processing/mapping of the information content as
observed from the external interfaces and do not impose a physical constraint within
the equipment.
Figure 2: Functional model of the cross connect equipment

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ETS 300 010-1: May 1995
7 General characteristics
7.1 Size
This parameter depends mainly on network growth and can therefore change with time. It shall be
possible to increase the size of an equipment without disturbing the existing traffic.
7.2 Timing signal
7.2.1 Control of timing signal
It should be possible to configure the equipment to derive the internal timing signal from:
a) one of a number of external source(s) at 2 048 kHz according to subclause 9.2;
b) one of a number of 2 048 kbit/s signal(s) according to subclause 9.1;
c) an internal oscillator.
On fault condition on the active synchronization signal it shall be possible to program a fall-back strategy
up to three steps; see subclause 11.2.1.2.
Complementary information corresponding to management aspects of the equipment will be provided in
ETS 300 010-2 (currently under development).
-11
The frequency accuracy of signals in a) and b) should normally be ± 1×10 . To take into account
possible frequency deviations on these signals occurring due to failure in the synchronous network, the
design of timing derivation circuits should assume a frequency accuracy of ± 1 part per million.
The requirements for the 2 048 kbit/s physical interface according to subclause 9.1.1 are not affected.
7.2.2 Timing performance
The timing performance of the internal clock shall comply with CCITT Recommendation G.812 [9]. In the
holdover mode, the local clock requirements of CCITT Recommendation G.812 [9], § 2.2.2 shall be met.
NOTE: For other timing performance options, refer to annex C.
8 Functions
The cross connect equipment shall perform the functions given in subclauses 8.1 and 8.2.
8.1 Cross connection
Cross connection of 64 and n x 64 kbit/s signals, bidirectional.
The n x 64 kbit/s signals shall be according to CCITT Recommendation G.704 [2], § 5.2. 6 x 64 kbit/s
(384 kbit/s) signals according to CCITT Recommendation G.735 [5], § 2.2.3 should be taken into account
in the design of the equipment. The equipment shall maintain octet sequence integrity of the signals being
cross connected.
NOTE 1: For some n x 64 kbit/s applications it may be necessary to maintain octet sequence
integrity within each frame.
NOTE 2: Refer to annex B for other n x 64 kbit/s Time Slot (TS) allocations.
8.2 Management
This includes control functions and provision of maintenance information and will be detailed in
ETS 300 010-2 (currently under development).

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ETS 300 010-1: May 1995
9 Interfaces
9.1 2 048 kbit/s interface
9.1.1 Physical interface
The 2 048 kbit/s physical interface shall be according to section 6 of CCITT Recommendation G.703 [1].
9.1.2 Frame structure
The details of frame structure carrying channels at various bit rates in 2 048 kbit/s shall be according to
CCITT Recommendation G.704 [2], § 2.3 and § 5. Bit 1 of the frame shall be used in accordance with
CCITT Recommendation G.704 [2], § 2.3.3, i.e. for a Cyclic Redundancy Check (CRC) procedure.
However, CCITT Recommendation G.735 [5], § 2.2.3 for TS allocation of 384 kbit/s sound programme
signals contained in a 2 048 kbit/s frame should be taken into account.
NOTE: Refer to annex B for other n x 64 kbit/s TS allocation.
9.2 Synchronization interface at 2 048 kHz
The physical and electrical characteristics of the synchronization interface shall be according to section 10
of CCITT Recommendation G.703 [1].
9.3 Interface with the TMN
The interface with the TMN shall be the Q interface according to CCITT Recommendation G.773 [7].
9.4 User interface
The user interface shall be the F interface according to CCITT Recommendation M.3010 [14].
9.5 Power supply interface
The power supply interface shall be the A interface according to CEPT Recommendation T/TR 02-02 [16]
(see note to clause 2).
10 Frame alignment and CRC procedure
An illustration of the procedure is given in figure 2 of CCITT Recommendation G.706 [3].
10.1 Loss of frame alignment
The strategy for loss of frame alignment shall be according to CCITT Recommendation G.706 [3], § 4.1.1.
10.2 Recovery of frame alignment
The strategy for recovery of frame alignment shall be according to CCITT Recommendation G.706 [3],
§ 4.1.2.
10.3 CRC multiframe alignment in TS 0
CRC multiframe alignment in TS 0 shall comply with CCITT Recommendation G.706 [3], § 4.2.
10.4 CRC bit monitoring
The CRC bit monitoring shall be performed according to CCITT Recommendation G.706 [3], § 4.3.

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ETS 300 010-1: May 1995
11 Defect or failure conditions and performance monitoring
11.1 Defect or failure conditions at the G2 (or A2) reference point and consequent actions at
the J2 (or G2) and G1 (or A1) reference points
11.1.1 Defect or failure condition
The equipment shall detect the conditions given in subclauses 11.1.1.1 to 11.1.1.6.
11.1.1.1 Failure of power supply
See table 1.
11.1.1.2 Loss of incoming signal at 2 048 kbit/s
The detection of this defect is required only when it does not result in an indication of loss of frame
alignment.
11.1.1.3 Loss of frame alignment
The strategy for loss of frame alignment shall be according to CCITT Recommendation G.706 [3], § 4.1.1.
-3
11.1.1.4 Error ratio 1:10
The detection of this defect shall comply with CCITT Recommendation G.736 [6], § 4.1.5.
The detection of this defect is optional. When required, it can be determined by counting either the
number of errored frame alignment signals or the number of errored bits in frame alignment signals or by
using the CRC procedure relating to the 2 048 kbit/s basic frame structure according to CCITT
Recommendation G.704 [2] (CRC 4). ETS 300 010-2 (currently under development) will cover the details
of this.
11.1.1.5 Reception of Alarm Indication Signal (AIS)
The detection of AIS shall comply with CCITT Recommendation G.736 [6], § 4.2.4, and CCITT
Recommendation O.162 [15], § 3.3.2.
11.1.1.6 Defect indication from a remote equipment
See table 1.
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ETS 300 010-1: May 1995
11.1.2 Consequent actions
Following to the detection of a defect or a failure condition, appropriate actions shall be taken as specified
in table 1. These actions should be taken as soon as possible:
- AIS at J2 reference point should be applied within 3 ms of the detection of the relevant defect or
failure condition;
- the maximum period between the detection of a defect or a failure condition and the transmission of
defect indication at the A1 reference point shall be of the order of 100 ms;
- the maximum period between the detection of a defect or a failure condition and the generation of
any failure information is dependant on the maintenance strategy for the equipment. This will be
covered in ETS 300 010-2 (currently under development).
-3
However, in case of the fault condition error ratio 1.10 provision shall be made for some form of
persistence check (e.g. 2 or 3 times the integration time) with appropriate confidence that a fault condition
does exist (see CCITT Recommendation G.736 [6], § 4.1.5.1 and § 4.1.5.2).
Table 1: Defect or failure conditions and consequent actions for a 2 048 kbit/s access port
Defect or failure Consequent actions
condition at G2 (or A2) reference pointFailure information Defect indication to AIS applied to data
generated (note 1) remote end at A1 TS at J2 reference
reference point point
Failure of power supply Yes if practicable
Loss of incoming signal Yes, bit 3 Yes
TS 0 NFAS
Loss of frame alignment Yes, bit 3 Yes
TS 0 NFAS
Error ratio Yes, bit 3 Yes
-3
1.10 (note 4) TS 0 NFAS (note 2)
Defect indication received from No No
remote end, bit 3 TS 0 NFAS
AIS received Yes (note 3) Yes
(note 5)
NOTE 1: Consequent actions related to the generation of failure information will be specified in
ETS 300 010-2 (currently under development). These actions could be taken at the level of
the equipment (e.g. bell, lamp, etc.) or at the level of the management of the equipment.
NOTE 2: Provision shall be made for disabling this action.
NOTE 3: In order to enable appropriate actions at the remote end, the indication of reception of AIS
may be transmitted in addition to any other defect information to the remote end. The use of
the 4 kbit/s data link on Sa4 in TS 0 NFAS or the use of a free Sa bit of TS 0 NFAS is
suggested for this application.
NOTE 4: The detection of this defect condition is optional.
NOTE 5: This consequent action is optional.

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ETS 300 010-1: May 1995
11.2 Defect or failure conditions and consequent actions for the core of the equipment
11.2.1 Defect or failure conditions
The equipment shall detect the conditions given in subclauses 11.2.1.1 and 11.2.1.2.
11.2.1.1 Failure of a connection
A connection inside the equipment shall be deemed to have failed when the 64 or n x 64 kbit/s path
between the A2 and A1 reference points of the relevant ports is not available for a period of more than 1 s.
11.2.1.2 Loss of synchronization signal(s)
The equipment is timed by its own internal oscillator in the case where this is not the normal mode of
operation. In the case of loss of active synchronization reference, the equipment shall switch over to
another reference according to the programmed fall-back strategy. In the case of selecting the internal
oscillator (case c) of subclause 7.2.1) the equipment shall enter into the holdover mode.
11.2.2 Consequent actions
Following the detection of a defect or a failure condition, appropriate consequent actions shall be taken as
specified in table 2. These actions shall be taken as soon as possible:
- the application of AIS at relevant J1 reference points (or J2 or A1) should be taken within 3 ms of
the detection of the failure condition;
- the maximum period between the detection of a defect or failure condition and the transmission of a
defect indication at the A1 reference point should be in the order of 100 ms;
- the maximum period between the detection of a defect or failure condition and the generation of any
failure information is dependent on the maintenance strategy for the equipment. ETS 300 010-2
(currently under development) will specify the management aspects of cross connect equipment.
Table 2: Defect or failure conditions and consequent actions for the core of the equipment
Consequent actions
Defect or failure condition Failure information Defect indication to AIS applied to data
generated (note 1) remote end at A1 TS at J1 reference
reference point point
(or J2 or A1)
Failure of a connection No Yes
(if practicable)
Loss of synchronization
signal(s) Yes, (note 2) No
NOTE 1: Consequent actions related to the generation of failure information will be specified in
ETS 300 010-2 (currently under development). These actions could be taken at the
level of the equipment (e.g. bell, lamp, etc.) or at the level of the management of the
equipment.
NOTE 2: This action should be taken at the level of all A1 reference points. In order to enable
appropriate actions at the remote ends the indication of loss of synchronization
signal(s) may be transmitted. The use of the 4 kbit/s data link on Sa4 in TS 0 NFAS or
the use of a free Sa bit of TS 0 NFAS is suggested for this application.
11.3 Performance monitoring
The following performance indications can be derived from error events or other defects:
- unavailable time;
- degraded performance;
- unacceptable performance.
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ETS 300 010-1: May 1995
The strategy to determine these quality performance parameters is described in CCITT Recommendation
M.20 [12] and CCITT Recommendation M.2100 [13]. See also ETS 300 010-2 (currently under
development) for the specification of management aspects of cross connect equipment.
12 Performance
12.1 Blocking factor
The blocking factor shall be zero for cross connect equipment of size up to at least 256 x 2 048 kbit/s
access ports.
12.2 Jitter
12.2.1 Jitter at 2 048 kbit/s output
When the timing source is jitter free, the peak-to-peak jitter at any 2 048 kbit/s output shall not exceed
0,05 Unit Interval when it is measured in the range from f1 = 20 Hz to f4 = 100 kHz (refer to figure 2 of
CCITT Recommendation G.823 [11]).
12.2.2 Jitter tolerance at 2 048 kbit/s input
The tolerance to jitter of any 2 048 kbit/s input port shall be according CCITT Recommendation
G.823 [11], § 3.
12.2.3 Jitter transfer function
The jitter transfer function between the input used for synchronization purposes and any 2 048 kbit/s
output shall not exceed the gain/frequency limits given in figure 3. The input signal shall be modulated with
sinusoidal jitter.
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ETS 300 010-1: May 1995
dB
20 dB/decade
0,5
400 Hz 100 kHz
f 40 Hz
-19,5
NOTE 1: The frequency f should be less than 20 Hz and as low as possible (e.g. 10 Hz), taking
into account the limitation of measuring equipment.
NOTE 2: To achieve accurate measurements, the use of a selective method is recommended
with a bandwidth sufficiently small referred to the relevant measurement frequency, but
not wider than 40 Hz.
Figure 3: Limits for jitter transfer function
12.3 Transfer delay
The transfer delay of 64 and n x 64 kbit/s signals through a cross connect equipment should be as small
as possible taking account of buffer sizes. The delay shall not exceed 650 μs between the connectors of
the corresponding access ports. For a temporary period this limit may be exceeded for existing
equipment.
12.4 Slips
Three situations should be considered:
a) in normal operation the timing signal and the relevant input signal are timed from the same CCITT
-11
Recommendation G.811 [8] 1×10 clock. No slip should occur, assuming adequate wander
buffers are provided;
b) the timing signal and the relevant input signal are timed from separate CCITT Recommendation
G.811 [8] clocks. In this plesiochronous mode of operation, the rate of controlled slips should be in
accordance with CCITT Recommendation G.822 [10], § 2.3;
c) the timing signal and the relevant input signal are independently timed as the result of loss of all
synchronization signals. The rate of controlled slips shall be limited to that caused by internal clock
frequency changes in
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