<s>
A	O
circuit	B-Protocol
ID	I-Protocol
is	O
a	O
company-specific	O
identifier	O
assigned	O
to	O
a	O
data	O
or	O
voice	O
network	O
connection	O
between	O
two	O
locations	O
.	O
</s>
<s>
In	O
this	O
way	O
,	O
the	O
circuit	B-Protocol
ID	I-Protocol
is	O
similar	O
to	O
a	O
serial	O
number	O
on	O
any	O
product	O
sold	O
from	O
a	O
retailer	O
to	O
a	O
customer	O
.	O
</s>
<s>
Each	O
circuit	B-Protocol
ID	I-Protocol
is	O
unique	O
,	O
so	O
a	O
specific	O
customer	O
having	O
many	O
circuit	O
connections	O
sold	O
to	O
them	O
would	O
have	O
many	O
circuit	B-Protocol
IDs	I-Protocol
to	O
refer	O
to	O
those	O
connections	O
.	O
</s>
<s>
As	O
an	O
example	O
of	O
a	O
use	O
of	O
the	O
circuit	B-Protocol
ID	I-Protocol
,	O
when	O
a	O
subscriber/customer	O
has	O
an	O
issue	O
(	O
or	O
trouble	O
)	O
with	O
a	O
circuit	O
,	O
they	O
may	O
contact	O
the	O
Controlling	O
Local	O
Exchange	O
Carrier	O
(	O
Controlling	O
LEC	O
)	O
telecommunications	O
provider	O
,	O
identifying	O
the	O
circuit	O
that	O
has	O
the	O
issue	O
by	O
giving	O
the	O
LEC	O
that	O
circuit	B-Protocol
ID	I-Protocol
reference	O
.	O
</s>
<s>
The	O
LEC	O
would	O
refer	O
to	O
their	O
internal	O
records	O
for	O
this	O
circuit	B-Protocol
ID	I-Protocol
to	O
take	O
corrective	O
action	O
on	O
the	O
designated	O
circuit	O
.	O
</s>
<s>
Although	O
telecommunication	O
providers	O
are	O
not	O
required	O
to	O
follow	O
any	O
specific	O
standard	O
for	O
circuit	B-Protocol
IDs	I-Protocol
,	O
many	O
do	O
.	O
</s>
<s>
In	O
the	O
United	O
States	O
,	O
LECs	O
typically	O
generate	O
circuit	B-Protocol
IDs	I-Protocol
based	O
on	O
Telcordia	O
Technologies	O
 '	O
Common	O
Language	O
Information	O
Services	O
.	O
</s>
<s>
The	O
way	O
Telcordia	O
has	O
developed	O
circuit	B-Protocol
IDs	I-Protocol
,	O
different	O
types	O
of	O
circuit	O
connections	O
require	O
different	O
formats	O
for	O
the	O
circuit	B-Protocol
ID	I-Protocol
.	O
</s>
<s>
Now	O
,	O
with	O
many	O
different	O
technologies	O
and	O
uses	O
for	O
circuit	O
connections	O
,	O
different	O
types	O
of	O
circuits	O
may	O
use	O
different	O
types	O
of	O
circuit	B-Protocol
ID	I-Protocol
formats	O
that	O
provide	O
more	O
meaning	O
for	O
that	O
type	O
of	O
circuit	O
.	O
</s>
<s>
Below	O
are	O
"	O
examples	O
"	O
of	O
how	O
one	O
telecommunications	O
provider	O
,	O
CenturyLink	B-Application
,	O
has	O
published	O
their	O
choice	O
for	O
circuit	B-Protocol
IDs	I-Protocol
for	O
three	O
different	O
types	O
of	O
circuit	O
connections	O
.	O
</s>
<s>
The	O
above	O
example	O
circuit	B-Protocol
ID	I-Protocol
represents	O
an	O
unframed	O
T3	O
circuit	O
between	O
two	O
locations	O
in	O
Minnesota	O
with	O
a	O
"	O
serial	O
number	O
"	O
of	O
HN101	O
.	O
</s>
<s>
For	O
more	O
on	O
Carrier	O
Facility	O
formatted	O
circuit	B-Protocol
IDs	I-Protocol
using	O
Telcordia	O
's	O
standards	O
,	O
see	O
Common	O
Language	O
Facility	O
Identification	O
.	O
</s>
<s>
Parts	O
of	O
this	O
circuit	B-Protocol
ID	I-Protocol
may	O
also	O
have	O
additional	O
intelligence	O
(	O
or	O
meaning	O
)	O
built	O
in	O
.	O
</s>
