Electronic and Postal Communications (Quality of Service)
G.N. No. 416 (contd)

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FIRST SCHEDULE
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(Made under Regulation 8)
QUALITY OF SERVICE PARAMETERS FOR PSTN SERVICES

S/No
Definition
1

Measurement

Supply time for initial connection
The duration from the instant a
valid service order being received
- % of orders completed by the
by a direct service provider to the
date agreed with the customer;
instant a working service is made
available for use. This includes
(Measurement to be made
cases where a new access line is
according to ETSI EG 201 769installed; an existing access line is
1)
taken over by another customer; or
an upgrade on the existing line.

2
The period starting when the
address information required for
setting up a call is received by the
network (e.g. recognized on the
calling user’s access line) and
finishing when the called party
busy tone or ringing tone or
answer signal is received by the
calling party.

Local call set-up time (s)
Post Selection Delay (in seconds)
[ITU-T Rec. E.721]
Mean value (in seconds)
(Measurements to be made
according to ETSI EG 201 7691)

Target Values

-

80% within 24
hrs;
- 90% within
48hrs;
100%
within 7
business
days.

The mean value of
the Post
Selection Delay (en
bloc) at normal load
should be 3.0sec
Mean value of local
call set-up time: <
3sec
Mean value of toll
call set-up time: <
5sec

3
Ratio of unsuccessful calls to the
total number of call attempts in a
specified time period.
An unsuccessful call is call
attempt to a valid number,
properly dialed following dial
tone, where neither called party
busy tone, ringing tone, nor
answer signal is recognized on the
access line of the calling user

Unsuccessful Call Ratio
Probability of end-to-end
blocking (ITU-T Rec. E.721);
Percentage of unsuccessful calls.
(Measurements to be made
according to ETSI EG 201 7691)
Call Completion Ratio: (CCR)

9

The mean value for
probability of endto-end blocking at
normal load should
be 2%

Local/Onnet/Intraoffice calls

Select target paragraph3