<s>
The	O
DMS-100	B-Protocol
is	O
a	O
member	O
of	O
the	O
Digital	B-Protocol
Multiplex	I-Protocol
System	I-Protocol
(	O
DMS	O
)	O
product	O
line	O
of	O
telephone	O
exchange	O
switches	O
manufactured	O
by	O
Northern	O
Telecom	O
.	O
</s>
<s>
The	O
purpose	O
of	O
the	O
DMS-100	B-Protocol
Switch	O
is	O
to	O
provide	O
local	O
service	O
and	O
connections	O
to	O
the	O
PSTN	O
public	O
telephone	O
network	O
.	O
</s>
<s>
It	O
provides	O
plain	O
old	O
telephone	O
service	O
(	O
POTS	O
)	O
,	O
mobility	O
management	O
for	O
cellular	O
phone	O
systems	O
,	O
sophisticated	O
business	O
services	O
such	O
as	O
automatic	O
call	O
distribution	O
(	O
ACD	O
)	O
,	O
Integrated	B-Protocol
Services	I-Protocol
Digital	I-Protocol
Network	I-Protocol
(	O
ISDN	B-Protocol
)	O
,	O
and	O
Meridian	O
Digital	O
Centrex	B-Device
(	O
MDC	O
)	O
,	O
formerly	O
called	O
Integrated	B-Device
Business	I-Device
Network	I-Device
(	O
IBN	O
)	O
.	O
</s>
<s>
It	O
also	O
provides	O
Intelligent	O
Network	O
functions	O
(	O
AIN	O
,	O
CS1-R	O
,	O
ETSI	O
INAP	B-Protocol
)	O
.	O
</s>
<s>
There	O
are	O
also	O
DMS-200	B-Protocol
and	O
DMS-250	B-Protocol
variants	O
for	O
tandem	B-Device
switches	I-Device
.	O
</s>
<s>
Much	O
of	O
the	O
hardware	O
used	O
in	O
the	O
DMS-100	B-Protocol
,	O
with	O
the	O
possible	O
exception	O
of	O
the	O
line	O
cards	O
,	O
is	O
used	O
in	O
other	O
members	O
of	O
the	O
DMS	O
family	O
,	O
including	O
the	O
DMS-200	B-Protocol
toll	O
switch	O
.	O
</s>
<s>
The	O
DMS	O
SuperNode	O
Computing	O
Module	O
was	O
first	O
based	O
on	O
the	O
Motorola	B-Device
68020	I-Device
Central	O
Processing	O
Unit	O
(	O
CPU	O
)	O
and	O
then	O
upgraded	O
to	O
the	O
Motorola	B-Device
68030	I-Device
.	O
</s>
<s>
In	O
the	O
early	O
1990s	O
it	O
was	O
further	O
upgraded	O
to	O
use	O
the	O
Motorola	O
88100	B-Architecture
and	I-Architecture
88110	I-Architecture
Reduced	B-Architecture
Instruction	I-Architecture
Set	I-Architecture
Computing	I-Architecture
(	O
RISC	B-Architecture
)	O
CPUs	O
.	O
</s>
<s>
This	O
RISC	B-Architecture
version	O
of	O
the	O
SuperNode	O
Computing	O
Module	O
was	O
known	O
as	O
the	O
BRISC	O
(	O
BNR	O
Reduced	B-Architecture
Instruction	I-Architecture
Set	I-Architecture
Computing	I-Architecture
)	O
CPU	O
.	O
</s>
<s>
The	O
Message	O
Switches	O
of	O
the	O
DMS	O
Bus	O
operate	O
in	O
a	O
load-sharing	O
mode	O
and	O
one	O
of	O
them	O
provides	O
the	O
main	O
clock	O
source	O
for	O
the	O
DMS-100	B-Protocol
system	O
while	O
the	O
others	O
are	O
synchronized	O
to	O
it	O
.	O
</s>
<s>
The	O
operating	O
system	O
used	O
by	O
both	O
generations	O
of	O
the	O
DMS-100	B-Protocol
switch	O
was	O
called	O
Support	O
Operating	O
System	O
(	O
SOS	O
)	O
and	O
was	O
written	O
in	O
a	O
high	O
level	O
language	O
called	O
PROTEL	B-Language
which	O
stood	O
for	O
PRocedure	O
Oriented	O
Type	O
Enforcing	O
Language	O
developed	O
at	O
Bell	O
Northern	O
Research	O
(	O
BNR	O
)	O
.	O
</s>
<s>
Analog	O
lines	O
are	O
terminated	O
on	O
individual	O
line	O
cards	O
,	O
each	O
with	O
its	O
own	O
codec	B-General_Concept
,	O
in	O
pull-out	O
Line	O
Drawers	O
in	O
frames	O
.	O
</s>
<s>
An	O
LCME	O
,	O
for	O
ISDN	B-Protocol
service	O
,	O
which	O
uses	O
NTBX27	O
cards	O
serve	O
Basic	B-Protocol
Rate	I-Protocol
ISDN	I-Protocol
lines	O
.	O
</s>
<s>
They	O
use	O
T1	B-Protocol
links	O
to	O
the	O
host	O
LGC	O
.	O
</s>
<s>
The	O
RCCs/RCC2s	O
are	O
usually	O
equipped	O
so	O
they	O
will	O
provide	O
calling	O
within	O
the	O
remote	O
office	O
if	O
the	O
host	O
links	O
fail	O
;	O
this	O
feature	O
is	O
called	O
ESA	O
;	O
Emergency	B-Protocol
Stand	I-Protocol
Alone	I-Protocol
.	O
</s>
<s>
They	O
used	O
2-6	O
T1	B-Protocol
links	O
on	O
copper	O
-	O
i.e.	O
</s>
<s>
Trunks	O
are	O
on	O
DTC	O
(	O
Digital	O
Trunk	O
Controller	O
)	O
or	O
DTCI	O
(	O
Digital	O
Trunk	O
Controller	O
ISDN	B-Protocol
)	O
or	O
PDTC	O
(	O
PCM30	O
Digital	O
Trunk	O
Controller	O
)	O
shelves	O
,	O
usually	O
two	O
T-1	B-Protocol
lines	O
per	O
card	O
,	O
ten	O
cards	O
per	O
DTC	O
for	O
a	O
total	O
of	O
480	O
ds0	O
voice	O
channels	O
.	O
</s>
<s>
At	O
the	O
turn	O
of	O
the	O
century	O
many	O
original	O
NT6X50AA	O
cards	O
were	O
still	O
in	O
service	O
that	O
cannot	O
perform	O
T-carrier	O
extended	O
superframe	O
signaling	O
,	O
this	O
can	O
be	O
performed	O
with	O
a	O
plug-in	O
replacement	O
NT6X50AB	O
card	O
,	O
used	O
for	O
services	O
such	O
as	O
PBX	O
ISDN	B-Protocol
T1s	O
.	O
</s>
<s>
Time	O
Division	O
switching	O
is	O
performed	O
in	O
E-Net	O
,	O
similar	O
to	O
the	O
Communication	O
Module	O
of	O
5ESS	B-Device
switch	I-Device
or	O
the	O
Switching	O
Network	O
of	O
EWSD	B-Device
or	O
the	O
Group	O
Switch	O
of	O
AXE	B-Device
telephone	I-Device
exchange	I-Device
.	O
</s>
<s>
There	O
are	O
also	O
DMS-200	B-Protocol
and	O
DMS-250	B-Protocol
variants	O
for	O
tandem	B-Device
switches	I-Device
.	O
</s>
<s>
In	O
2006	O
Nortel	O
introduced	O
the	O
Communication	O
Server	O
1500	O
(	O
CS	O
1500	O
)	O
Softswitch	O
based	O
on	O
VOIP	B-Application
to	O
modernize	O
the	O
DMS-based	O
telephone	O
switches	O
.	O
</s>
<s>
A	O
CS	O
1500	O
softswitch	O
system	O
can	O
replace	O
all	O
the	O
DMS	O
component	O
modules	O
except	O
for	O
the	O
LCMs	O
,	O
reducing	O
the	O
footprint	O
of	O
a	O
DMS-100	B-Protocol
to	O
one	O
19	O
"	O
rack	O
and	O
allowing	O
operators	O
to	O
reduce	O
cooling	O
and	O
power	O
requirements	O
significantly	O
.	O
</s>
<s>
A	O
successor	O
to	O
the	O
DMS-100	B-Protocol
is	O
the	O
Communication	O
Server	O
2000	O
(	O
CS2K	O
)	O
,	O
which	O
shares	O
many	O
components	O
and	O
software	O
with	O
the	O
DMS	O
.	O
</s>
<s>
The	O
significant	O
difference	O
is	O
the	O
addition	O
of	O
VOIP	B-Application
technology	O
into	O
the	O
CS2K	O
.	O
</s>
<s>
In	O
2010	O
,	O
Genband	O
purchased	O
Nortel	O
Networks	O
 '	O
Carrier	O
VoIP	B-Application
and	O
Application	O
Solutions	O
(	O
CVAS	O
)	O
business	O
for	O
$182.5	O
million	O
.	O
</s>
