<s>
Data	B-Protocol
Over	I-Protocol
Cable	I-Protocol
Service	I-Protocol
Interface	I-Protocol
Specification	I-Protocol
(	O
DOCSIS	B-Protocol
)	O
is	O
an	O
international	O
telecommunications	O
standard	O
that	O
permits	O
the	O
addition	O
of	O
high-bandwidth	O
data	O
transfer	O
to	O
an	O
existing	O
cable	O
television	O
(	O
CATV	O
)	O
system	O
.	O
</s>
<s>
It	O
is	O
used	O
by	O
many	O
cable	O
television	O
operators	O
to	O
provide	O
cable	B-Device
Internet	I-Device
access	I-Device
over	O
their	O
existing	O
hybrid	B-Architecture
fiber-coaxial	I-Architecture
(	O
HFC	O
)	O
infrastructure	O
.	O
</s>
<s>
DOCSIS	B-Protocol
was	O
originally	O
developed	O
by	O
CableLabs	O
and	O
contributing	O
companies	O
,	O
including	O
Arris	O
,	O
BigBand	O
Networks	O
,	O
Broadcom	O
,	O
Cisco	O
,	O
Comcast	O
,	O
Conexant	O
,	O
Correlant	O
,	O
Cox	O
,	O
Harmonic	O
,	O
Intel	O
,	O
Motorola	O
,	O
Netgear	O
,	O
Terayon	O
,	O
Time	O
Warner	O
Cable	O
,	O
and	O
Texas	O
Instruments	O
.	O
</s>
<s>
Released	O
in	O
March	O
1997	O
,	O
DOCSIS	B-Protocol
1.0	O
included	O
functional	O
elements	O
from	O
preceding	O
proprietary	O
cable	B-Device
modems	I-Device
.	O
</s>
<s>
Released	O
in	O
April	O
1999	O
,	O
DOCSIS	B-Protocol
1.1	O
standardized	O
quality	O
of	O
service	O
(	O
QoS	O
)	O
mechanisms	O
that	O
were	O
outlined	O
in	O
DOCSIS	B-Protocol
1.0	O
.	O
</s>
<s>
Released	O
in	O
December	O
2001	O
,	O
DOCSIS	B-Protocol
2.0	O
enhanced	O
upstream	O
data	O
rates	O
in	O
response	O
to	O
increased	O
demand	O
for	O
symmetric	O
services	O
such	O
as	O
IP	B-Application
telephony	I-Application
.	O
</s>
<s>
Released	O
in	O
August	O
2006	O
,	O
DOCSIS	B-Protocol
3.0	I-Protocol
significantly	O
increased	O
data	O
rates	O
(	O
both	O
upstream	O
and	O
downstream	O
)	O
and	O
introduced	O
support	O
for	O
Internet	B-Protocol
Protocol	I-Protocol
version	I-Protocol
6	I-Protocol
(	O
IPv6	B-Protocol
)	O
.	O
</s>
<s>
First	O
released	O
in	O
October	O
2013	O
,	O
and	O
subsequently	O
updated	O
several	O
times	O
,	O
the	O
DOCSIS	B-Protocol
3.1	I-Protocol
suite	O
of	O
specifications	O
support	O
capacities	O
of	O
up	O
to	O
10Gbit/s	O
downstream	O
and	O
1Gbit/s	O
upstream	O
using	O
4096	O
QAM	B-Device
.	O
</s>
<s>
The	O
new	O
specifications	O
eliminated	O
6MHz	O
and	O
8MHz	O
wide	O
channel	O
spacing	O
and	O
instead	O
use	O
narrower	O
(	O
25kHz	O
or	O
50kHz	O
wide	O
)	O
orthogonal	B-Protocol
frequency-division	I-Protocol
multiplexing	I-Protocol
(	O
OFDM	B-Protocol
)	O
subcarriers	O
;	O
these	O
can	O
be	O
bonded	B-Architecture
inside	O
a	O
block	O
spectrum	O
that	O
could	O
end	O
up	O
being	O
about	O
200MHz	O
wide	O
.	O
</s>
<s>
DOCSIS	B-Protocol
3.1	I-Protocol
technology	O
also	O
includes	O
power-management	O
features	O
that	O
will	O
enable	O
the	O
cable	O
industry	O
to	O
reduce	O
its	O
energy	O
usage	O
,	O
and	O
the	O
DOCSIS-PIE	O
algorithm	O
to	O
reduce	O
bufferbloat	O
.	O
</s>
<s>
In	O
the	O
United	O
States	O
,	O
broadband	O
provider	O
Comcast	O
announced	O
in	O
February	O
2016	O
that	O
several	O
cities	O
within	O
its	O
footprint	O
will	O
have	O
DOCSIS	B-Protocol
3.1	I-Protocol
availability	O
before	O
the	O
end	O
of	O
the	O
year	O
.	O
</s>
<s>
At	O
the	O
end	O
of	O
2016	O
,	O
Mediacom	O
announced	O
it	O
would	O
become	O
the	O
first	O
major	O
U.S.	O
cable	O
company	O
to	O
fully	O
transition	O
to	O
the	O
DOCSIS	B-Protocol
3.1	I-Protocol
platform	O
.	O
</s>
<s>
Improves	O
DOCSIS	B-Protocol
3.1	I-Protocol
to	O
use	O
the	O
full	O
spectrum	O
of	O
the	O
cable	O
plant	O
(	O
0MHz	O
to	O
~	O
1.8GHz	O
)	O
at	O
the	O
same	O
time	O
in	O
both	O
upstream	O
and	O
downstream	O
directions	O
.	O
</s>
<s>
This	O
technology	O
enables	O
multi-gigabit	O
symmetrical	O
services	O
while	O
retaining	O
backward	B-General_Concept
compatibility	I-General_Concept
with	O
DOCSIS	B-Protocol
3.1	I-Protocol
.	O
</s>
<s>
Previously	O
branded	O
as	O
DOCSIS	B-Protocol
3.1	I-Protocol
Full	O
Duplex	O
,	O
these	O
technologies	O
have	O
been	O
rebranded	O
as	O
part	O
of	O
DOCSIS	B-Protocol
4.0	O
.	O
</s>
<s>
In	O
1994	O
,	O
802.14	O
was	O
chartered	O
to	O
develop	O
a	O
media	B-Protocol
access	I-Protocol
control	I-Protocol
over	O
an	O
HFC	O
.	O
</s>
<s>
As	O
frequency	O
allocation	O
bandwidth	O
plans	O
differ	O
between	O
United	O
States	O
and	O
European	O
CATV	O
systems	O
,	O
DOCSIS	B-Protocol
standards	O
earlier	O
than	O
3.1	O
have	O
been	O
modified	O
for	O
use	O
in	O
Europe	O
.	O
</s>
<s>
These	O
modifications	O
were	O
published	O
under	O
the	O
name	O
EuroDOCSIS	B-Protocol
.	O
</s>
<s>
The	O
differences	O
between	O
the	O
bandwidths	O
exist	O
because	O
European	O
cable	O
TV	O
conforms	O
to	O
PAL/DVB	O
-C	O
standards	O
of	O
8MHz	O
RF	O
channel	O
bandwidth	O
and	O
North	O
American	O
cable	O
TV	O
conforms	O
to	O
NTSC/ATSC	O
standards	O
which	O
specify	O
6MHz	O
per	O
channel	O
.	O
</s>
<s>
The	O
wider	O
channel	O
bandwidth	O
in	O
EuroDOCSIS	B-Protocol
architectures	O
permits	O
more	O
bandwidth	O
to	O
be	O
allocated	O
to	O
the	O
downstream	O
data	O
path	O
(	O
toward	O
the	O
user	O
)	O
.	O
</s>
<s>
EuroDOCSIS	B-Protocol
certification	O
testing	O
is	O
executed	O
by	O
Belgian	O
company	O
Excentis	O
(	O
formerly	O
known	O
as	O
tComLabs	O
)	O
,	O
while	O
DOCSIS	B-Protocol
certification	O
testing	O
is	O
executed	O
by	O
CableLabs	O
.	O
</s>
<s>
The	O
ITU	O
Telecommunication	O
Standardization	O
Sector	O
(	O
ITU-T	O
)	O
has	O
approved	O
the	O
various	O
versions	O
of	O
DOCSIS	B-Protocol
as	O
international	O
standards	O
.	O
</s>
<s>
DOCSIS	B-Protocol
1.0	O
was	O
ratified	O
as	O
ITU-T	O
Recommendation	O
J.112	O
Annex	O
B	O
(	O
1998	O
)	O
,	O
but	O
it	O
was	O
superseded	O
by	O
DOCSIS	B-Protocol
1.1	O
which	O
was	O
ratified	O
as	O
ITU-T	O
Recommendation	O
Annex	O
B	O
(	O
2001	O
)	O
.	O
</s>
<s>
Subsequently	O
,	O
DOCSIS	B-Protocol
2.0	O
was	O
ratified	O
as	O
ITU-T	O
Recommendation	O
.	O
</s>
<s>
Most	O
recently	O
,	O
DOCSIS	B-Protocol
3.0	I-Protocol
was	O
ratified	O
as	O
ITU-T	O
Recommendation	O
J.222	O
(	O
,	O
,	O
,	O
)	O
.	O
</s>
<s>
Note	O
:	O
While	O
ITU-T	O
Recommendation	O
J.112	O
Annex	O
B	O
corresponds	O
to	O
DOCSIS/EuroDOCSIS	O
1.1	O
,	O
Annex	O
A	O
describes	O
an	O
earlier	O
European	O
cable	B-Device
modem	I-Device
system	O
(	O
"	O
DVB	B-Application
EuroModem	O
"	O
)	O
based	O
on	O
ATM	O
transmission	O
standards	O
.	O
</s>
<s>
Annex	O
C	O
describes	O
a	O
variant	O
of	O
DOCSIS	B-Protocol
1.1	O
that	O
is	O
designed	O
to	O
operate	O
in	O
Japanese	O
cable	O
systems	O
.	O
</s>
<s>
The	O
ITU-T	O
Recommendation	O
J.122	O
main	O
body	O
corresponds	O
to	O
DOCSIS	B-Protocol
2.0	O
,	O
J.122	O
Annex	O
F	O
corresponds	O
to	O
EuroDOCSIS	B-Protocol
2.0	O
,	O
and	O
J.122	O
Annex	O
J	O
describes	O
the	O
Japanese	O
variant	O
of	O
DOCSIS	B-Protocol
2.0	O
(	O
analogous	O
to	O
Annex	O
C	O
of	O
J.112	O
)	O
.	O
</s>
<s>
DOCSIS	B-Protocol
provides	O
a	O
variety	O
of	O
options	O
available	O
at	O
Open	O
Systems	O
Interconnection	O
(	O
OSI	O
)	O
layers	O
1	O
and	O
2	O
—	O
the	O
physical	B-Application
and	O
data	B-Protocol
link	I-Protocol
layers	I-Protocol
.	O
</s>
<s>
Downstream	O
:	O
All	O
versions	O
of	O
DOCSIS	B-Protocol
earlier	O
than	O
3.1	O
use	O
either	O
6MHz	O
channels	O
(	O
e.g.	O
</s>
<s>
North	O
America	O
)	O
or	O
8MHz	O
channels	O
(	O
"	O
EuroDOCSIS	B-Protocol
"	O
)	O
.	O
</s>
<s>
DOCSIS	B-Protocol
3.1	I-Protocol
uses	O
channel	O
bandwidths	O
of	O
up	O
to	O
192MHz	O
in	O
the	O
downstream	O
.	O
</s>
<s>
Upstream	O
:	O
DOCSIS	B-Protocol
1.0/1.1	O
specifies	O
channel	O
widths	O
between	O
200kHz	O
and	O
3.2MHz	O
.	O
</s>
<s>
DOCSIS	B-Protocol
2.0	O
&	O
3.0	O
specify	O
6.4MHz	O
,	O
but	O
can	O
use	O
the	O
earlier	O
,	O
narrower	O
channel	O
widths	O
for	O
backward	B-General_Concept
compatibility	I-General_Concept
.	O
</s>
<s>
DOCSIS	B-Protocol
3.1	I-Protocol
uses	O
channel	O
bandwidths	O
of	O
up	O
to	O
96MHz	O
in	O
the	O
upstream	O
.	O
</s>
<s>
Downstream	O
:	O
All	O
versions	O
of	O
DOCSIS	B-Protocol
prior	O
to	O
3.1	O
specify	O
that	O
64-level	O
or	O
256-level	O
QAM	B-Device
(	O
64-QAM	B-Device
or	O
256-QAM	B-Device
)	O
be	O
used	O
for	O
modulation	O
of	O
downstream	O
data	O
,	O
using	O
the	O
ITU-T	O
J.83-Annex	O
B	O
standard	O
for	O
6MHz	O
channel	O
operation	O
,	O
and	O
the	O
DVB-C	B-Device
modulation	O
standard	O
for	O
8MHz	O
(	O
EuroDOCSIS	B-Protocol
)	O
operation	O
.	O
</s>
<s>
DOCSIS	B-Protocol
3.1	I-Protocol
adds	O
16-QAM	B-Device
,	O
128-QAM	B-Device
,	O
512-QAM	B-Device
,	O
1024-QAM	B-Device
,	O
2048-QAM	B-Device
and	O
4096-QAM	B-Device
,	O
with	O
optional	O
support	O
of	O
8192-QAM/16384	O
-QAM	O
.	O
</s>
<s>
Upstream	O
:	O
Upstream	O
data	O
uses	O
QPSK	O
or	O
16-level	O
QAM	B-Device
(	O
16-QAM	B-Device
)	O
for	O
DOCSIS	B-Protocol
1.x	O
,	O
while	O
QPSK	O
,	O
8-QAM	B-Device
,	O
16-QAM	B-Device
,	O
32-QAM	B-Device
,	O
and	O
64-QAM	B-Device
are	O
used	O
for	O
DOCSIS	B-Protocol
2.0	O
and	O
3.0	O
.	O
</s>
<s>
DOCSIS	B-Protocol
2.0	O
and	O
3.0	O
also	O
support	O
128-QAM	B-Device
with	O
trellis	O
coded	O
modulation	O
in	O
S-CDMA	O
mode	O
(	O
with	O
an	O
effective	O
spectral	B-Protocol
efficiency	I-Protocol
equivalent	O
to	O
that	O
of	O
64-QAM	B-Device
)	O
.	O
</s>
<s>
DOCSIS	B-Protocol
3.1	I-Protocol
supports	O
data	O
modulations	O
from	O
QPSK	O
up	O
to	O
1024-QAM	B-Device
,	O
with	O
optional	O
support	O
for	O
2048-QAM	B-Device
and	O
4096-QAM	B-Device
.	O
</s>
<s>
DOCSIS	B-Protocol
employs	O
a	O
mixture	O
of	O
deterministic	O
access	O
methods	O
for	O
upstream	O
transmissions	O
,	O
specifically	O
time-division	O
multiple	O
access	O
(	O
TDMA	O
)	O
for	O
DOCSIS	B-Protocol
1.0/1.1	O
and	O
both	O
TDMA	O
and	O
S-CDMA	O
for	O
DOCSIS	B-Protocol
2.0	O
and	O
3.0	O
,	O
with	O
a	O
limited	O
use	O
of	O
contention	O
for	O
bandwidth	O
requests	O
.	O
</s>
<s>
Because	O
of	O
this	O
,	O
DOCSIS	B-Protocol
systems	O
experience	O
relatively	O
few	O
collisions	O
,	O
in	O
contrast	O
to	O
the	O
pure	O
contention-based	O
MAC	O
CSMA/CD	O
employed	O
in	O
older	O
Ethernet	O
systems	O
(	O
of	O
course	O
,	O
there	O
is	O
no	O
contention	O
in	O
switched	B-Protocol
Ethernet	I-Protocol
)	O
.	O
</s>
<s>
For	O
DOCSIS	B-Protocol
1.1	O
and	O
above	O
,	O
the	O
data	O
layer	O
also	O
includes	O
extensive	O
quality-of-service	O
(	O
QoS	O
)	O
features	O
that	O
help	O
to	O
efficiently	O
support	O
applications	O
that	O
have	O
specific	O
traffic	O
requirements	O
such	O
as	O
low	O
latency	O
,	O
e.g.	O
</s>
<s>
voice	B-Application
over	I-Application
IP	I-Application
.	O
</s>
<s>
DOCSIS	B-Protocol
3.0	I-Protocol
features	O
channel	B-Architecture
bonding	I-Architecture
,	O
which	O
enables	O
multiple	O
downstream	O
and	O
upstream	O
channels	O
to	O
be	O
used	O
together	O
at	O
the	O
same	O
time	O
by	O
a	O
single	O
subscriber	O
.	O
</s>
<s>
The	O
first	O
three	O
versions	O
of	O
the	O
DOCSIS	B-Protocol
standard	O
support	O
a	O
downstream	O
throughput	O
with	O
256-QAM	B-Device
of	O
up	O
to	O
42.88Mbit/s	O
per	O
6MHz	O
channel	O
(	O
approximately	O
38Mbit/s	O
after	O
overhead	O
)	O
,	O
or	O
55.62Mbit/s	O
per	O
8MHz	O
channel	O
for	O
EuroDOCSIS	B-Protocol
(	O
approximately	O
50Mbit/s	O
after	O
overhead	O
)	O
.	O
</s>
<s>
DOCSIS	B-Protocol
3.1	I-Protocol
supports	O
a	O
downstream	O
throughput	O
with	O
4096-QAM	B-Device
and	O
25kHz	O
subcarrier	O
spacing	O
of	O
up	O
to	O
1.89Gbit/s	O
per	O
192MHz	O
OFDM	B-Protocol
channel	O
.	O
</s>
<s>
DOCSIS	B-Protocol
modems	O
are	O
managed	O
via	O
an	O
Internet	B-Protocol
Protocol	I-Protocol
(	O
IP	O
)	O
address	O
.	O
</s>
<s>
The	O
'	O
DOCSIS	B-Protocol
2.0	O
+	O
IPv6	B-Protocol
 '	O
specification	O
allowed	O
support	O
for	O
IPv6	B-Protocol
on	O
DOCSIS	B-Protocol
2.0	O
modems	O
via	O
a	O
firmware	O
upgrade	O
.	O
</s>
<s>
DOCSIS	B-Protocol
3.0	I-Protocol
added	O
management	O
over	O
IPv6	B-Protocol
.	O
</s>
<s>
Tables	O
assume	O
256-QAM	B-Device
modulation	O
for	O
downstream	O
and	O
64-QAM	B-Device
for	O
upstream	O
on	O
DOCSIS	B-Protocol
3.0	I-Protocol
,	O
and	O
4096-QAM	B-Device
modulation	O
for	O
OFDM/OFDMA	O
(	O
first	O
downstream/upstream	O
methods	O
)	O
on	O
DOCSIS	B-Protocol
3.1	I-Protocol
,	O
although	O
real-world	O
data	O
rates	O
may	O
be	O
lower	O
due	O
to	O
variable	O
modulation	O
depending	O
on	O
SNR	O
.	O
</s>
<s>
Higher	O
data	O
rates	O
are	O
possible	O
but	O
require	O
higher	O
order	O
QAM	B-Device
schemes	O
which	O
require	O
higher	O
downstream	O
modulation	O
error	O
ratio	O
(	O
MER	O
)	O
.	O
</s>
<s>
DOCSIS	B-Protocol
3.1	I-Protocol
was	O
designed	O
to	O
support	O
up	O
to	O
8192-QAM/16	O
,	O
384-QAM	O
,	O
but	O
only	O
support	O
of	O
up	O
through	O
4096-QAM	B-Device
is	O
mandatory	O
to	O
meet	O
the	O
minimum	O
DOCSIS	B-Protocol
3.1	I-Protocol
standards	O
.	O
</s>
<s>
For	O
DOCSIS	B-Protocol
3.0	I-Protocol
,	O
the	O
theoretical	O
maximum	O
throughput	O
for	O
the	O
number	O
of	O
bonded	B-Architecture
channels	O
are	O
listed	O
in	O
the	O
table	O
below	O
.	O
</s>
<s>
Note	O
that	O
the	O
maximum	O
downstream	O
bandwidth	O
on	O
all	O
versions	O
of	O
DOCSIS	B-Protocol
depends	O
on	O
the	O
version	O
of	O
DOCSIS	B-Protocol
used	O
and	O
the	O
number	O
of	O
upstream	O
channels	O
used	O
if	O
DOCSIS	B-Protocol
3.0	I-Protocol
is	O
used	O
,	O
but	O
the	O
upstream	O
channel	O
widths	O
are	O
independent	O
of	O
whether	O
DOCSIS	B-Protocol
or	O
EuroDOCSIS	B-Protocol
is	O
used	O
.	O
</s>
<s>
Traditional	O
DOCSIS	B-Protocol
upstream	O
in	O
North	O
America	O
uses	O
the	O
5	O
–	O
42MHz	O
frequency	O
range	O
.	O
</s>
<s>
The	O
5	O
–	O
65MHz	O
range	O
is	O
used	O
by	O
EuroDOCSIS	B-Protocol
.	O
</s>
<s>
This	O
is	O
known	O
as	O
a	O
"	O
low-split	O
"	O
or	O
"	O
sub-split	O
"	O
design	O
,	O
capable	O
of	O
a	O
total	O
shared	O
capacity	O
of	O
~	O
108Mbit/s	O
upstream	O
(	O
assuming	O
4	O
SC-QAM	O
upstream	O
channels	O
)	O
.	O
</s>
<s>
A	O
mid-split	O
increases	O
the	O
upstream	O
frequency	O
range	O
to	O
5	O
–	O
85MHz	O
,	O
supporting	O
a	O
total	O
shared	O
upstream	O
capacity	O
of	O
~	O
450Mbit/s	O
(	O
assuming	O
4	O
SC-QAM	O
+	O
OFDMA	O
channels	O
)	O
.	O
</s>
<s>
A	O
high-split	O
increases	O
the	O
upstream	O
frequency	O
range	O
to	O
5	O
–	O
204MHz	O
,	O
supporting	O
a	O
total	O
shared	O
upstream	O
capacity	O
of	O
~	O
1.5Gbit/s	O
(	O
assuming	O
4	O
SC-QAM	O
+	O
OFDMA	O
channels	O
)	O
.	O
</s>
<s>
DOCSIS4.0	O
in	O
both	O
full-duplex	O
(	O
FDX	O
)	O
and	O
extended	O
spectrum	O
DOCSIS	B-Protocol
(	O
ESD	O
)	O
configurations	O
will	O
support	O
upstream	O
speeds	O
surpassing	O
5Gbit/s	O
.	O
</s>
<s>
A	O
DOCSIS	B-Protocol
architecture	O
includes	O
two	O
primary	O
components	O
:	O
a	O
cable	B-Device
modem	I-Device
located	O
at	O
the	O
customer	O
premises	O
,	O
and	O
a	O
cable	B-Device
modem	I-Device
termination	I-Device
system	I-Device
(	O
CMTS	O
)	O
located	O
at	O
the	O
CATV	O
headend	O
.	O
</s>
<s>
Cable	O
systems	O
supporting	O
on-demand	O
programming	O
use	O
a	O
hybrid	B-Architecture
fiber-coaxial	I-Architecture
system	O
.	O
</s>
<s>
Fiber	O
optic	O
lines	O
bring	O
digital	O
signals	O
to	O
optical	O
nodes	B-Protocol
in	O
the	O
system	O
where	O
they	O
are	O
converted	O
into	O
RF	O
channels	O
and	O
modem	O
signals	O
on	O
coaxial	O
trunk	O
lines	O
.	O
</s>
<s>
The	O
CPE	O
are	O
connected	O
to	O
the	O
cable	B-Device
modem	I-Device
,	O
which	O
is	O
in	O
turn	O
connected	O
through	O
the	O
HFC	B-Architecture
network	I-Architecture
to	O
the	O
CMTS	O
.	O
</s>
<s>
Using	O
provisioning	O
systems	O
and	O
through	O
the	O
CMTS	O
,	O
the	O
cable	O
operator	O
exercises	O
control	O
over	O
the	O
cable	B-Device
modem	I-Device
's	O
configuration	O
.	O
</s>
<s>
DOCSIS	B-Protocol
2.0	O
is	O
also	O
used	O
over	O
microwave	O
frequencies	O
(	O
10GHz	O
)	O
in	O
Ireland	O
by	O
Digiweb	O
,	O
using	O
dedicated	O
wireless	O
links	O
rather	O
than	O
HFC	B-Architecture
network	I-Architecture
.	O
</s>
<s>
DOCSIS	B-Protocol
includes	O
media	B-Protocol
access	I-Protocol
control	I-Protocol
(	O
MAC	O
)	O
layer	O
security	O
services	O
in	O
its	O
Baseline	O
Privacy	O
Interface	O
specifications	O
.	O
</s>
<s>
DOCSIS	B-Protocol
1.0	O
used	O
the	O
initial	O
Baseline	O
Privacy	O
Interface	O
(	O
BPI	O
)	O
specification	O
.	O
</s>
<s>
BPI	O
was	O
later	O
improved	O
with	O
the	O
release	O
of	O
the	O
Baseline	O
Privacy	O
Interface	O
Plus	O
(	O
BPI+	O
)	O
specification	O
used	O
by	O
DOCSIS	B-Protocol
1.1	O
and	O
2.0	O
.	O
</s>
<s>
Most	O
recently	O
,	O
a	O
number	O
of	O
enhancements	O
to	O
the	O
Baseline	O
Privacy	O
Interface	O
were	O
added	O
as	O
part	O
of	O
DOCSIS	B-Protocol
3.0	I-Protocol
,	O
and	O
the	O
specification	O
was	O
renamed	O
"	O
Security	O
"	O
(	O
SEC	O
)	O
.	O
</s>
<s>
The	O
intent	O
of	O
the	O
BPI/SEC	O
specifications	O
is	O
to	O
describe	O
MAC	B-Protocol
layer	I-Protocol
security	O
services	O
for	O
DOCSIS	B-Protocol
CMTS	O
to	O
cable	B-Device
modem	I-Device
communications	O
.	O
</s>
<s>
It	O
does	O
this	O
by	O
encrypting	O
data	O
flows	O
between	O
the	O
CMTS	O
and	O
the	O
cable	B-Device
modem	I-Device
.	O
</s>
<s>
BPI	O
and	O
BPI+	O
use	O
56-bit	O
Data	B-Algorithm
Encryption	I-Algorithm
Standard	I-Algorithm
(	O
DES	B-Algorithm
)	O
encryption	O
,	O
while	O
SEC	O
adds	O
support	O
for	O
128-bit	O
Advanced	B-Algorithm
Encryption	I-Algorithm
Standard	I-Algorithm
(	O
AES	B-Algorithm
)	O
.	O
</s>
<s>
The	O
AES	B-Algorithm
key	I-Algorithm
,	O
however	O
,	O
is	O
protected	O
only	O
by	O
a	O
1024-bit	O
RSA	O
key	O
.	O
</s>
<s>
BPI/SEC	O
is	O
intended	O
to	O
allow	O
cable	O
service	O
operators	O
to	O
refuse	O
service	O
to	O
uncertified	O
cable	B-Device
modems	I-Device
and	O
unauthorized	O
users	O
.	O
</s>
<s>
BPI+	O
strengthened	O
service	O
protection	O
by	O
adding	O
digital	O
certificate	O
based	O
authentication	O
to	O
its	O
key	O
exchange	O
protocol	O
,	O
using	O
a	O
public	B-Architecture
key	I-Architecture
infrastructure	I-Architecture
(	O
PKI	O
)	O
,	O
based	O
on	O
digital	O
certificate	B-Architecture
authorities	I-Architecture
(	O
CAs	O
)	O
of	O
the	O
certification	O
testers	O
,	O
currently	O
Excentis	O
(	O
formerly	O
known	O
as	O
tComLabs	O
)	O
for	O
EuroDOCSIS	B-Protocol
and	O
CableLabs	O
for	O
DOCSIS	B-Protocol
.	O
</s>
<s>
Typically	O
,	O
the	O
cable	O
service	O
operator	O
manually	O
adds	O
the	O
cable	B-Device
modem	I-Device
's	O
MAC	O
address	O
to	O
a	O
customer	O
's	O
account	O
with	O
the	O
cable	O
service	O
operator	O
;	O
and	O
the	O
network	O
allows	O
access	O
only	O
to	O
a	O
cable	B-Device
modem	I-Device
that	O
can	O
attest	O
to	O
that	O
MAC	O
address	O
using	O
a	O
valid	O
certificate	O
issued	O
via	O
the	O
PKI	O
.	O
</s>
<s>
The	O
earlier	O
BPI	O
specification	O
(	O
ANSI/SCTE	O
)	O
had	O
limited	O
service	O
protection	O
because	O
the	O
underlying	O
key	O
management	O
protocol	O
did	O
not	O
authenticate	O
the	O
user	O
's	O
cable	B-Device
modem	I-Device
.	O
</s>
<s>
Security	O
in	O
the	O
DOCSIS	B-Protocol
network	O
is	O
vastly	O
improved	O
when	O
only	O
business	O
critical	O
communications	O
are	O
permitted	O
,	O
and	O
end	O
user	O
communication	O
to	O
the	O
network	O
infrastructure	O
is	O
denied	O
.	O
</s>
<s>
Successful	O
attacks	O
often	O
occur	O
when	O
the	O
CMTS	O
is	O
configured	O
for	O
backward	B-General_Concept
compatibility	I-General_Concept
with	O
early	O
pre-standard	O
DOCSIS	B-Protocol
1.1	O
modems	O
.	O
</s>
<s>
These	O
modems	O
were	O
"	O
software	O
upgradeable	O
in	O
the	O
field	O
"	O
,	O
but	O
did	O
not	O
include	O
valid	O
DOCSIS	B-Protocol
or	O
EuroDOCSIS	B-Protocol
root	O
certificates	O
.	O
</s>
