<s>
The	O
Skinny	B-Protocol
Client	I-Protocol
Control	I-Protocol
Protocol	I-Protocol
(	O
SCCP	O
)	O
is	O
a	O
proprietary	O
network	O
terminal	O
control	O
protocol	O
originally	O
developed	O
by	O
Selsius	O
Systems	O
,	O
which	O
was	O
acquired	O
by	O
Cisco	O
Systems	O
in	O
1998	O
.	O
</s>
<s>
The	O
protocol	O
architecture	O
is	O
similar	O
to	O
the	O
media	B-Protocol
gateway	I-Protocol
control	I-Protocol
protocol	I-Protocol
architecture	O
,	O
in	O
that	O
is	O
decomposes	O
the	O
function	O
of	O
media	O
conversion	O
in	O
telecommunication	O
for	O
transmission	O
via	O
an	O
Internet	B-Protocol
Protocol	I-Protocol
network	O
into	O
a	O
relatively	O
low-intelligence	O
customer-premises	O
device	O
and	O
a	O
call	O
agent	O
implementation	O
that	O
controls	O
the	O
CPE	O
via	O
signaling	O
commands	O
.	O
</s>
<s>
The	O
call	O
agent	O
product	O
is	O
Cisco	O
CallManager	O
,	O
which	O
also	O
performs	O
as	O
a	O
signaling	O
proxy	O
for	O
call	O
events	O
initiated	O
over	O
other	O
common	O
protocols	O
such	O
as	O
H.323	B-Protocol
,	O
and	O
Session	B-Application
Initiation	I-Application
Protocol	I-Application
(	O
SIP	O
)	O
for	O
voice	B-Application
over	I-Application
IP	I-Application
,	O
or	O
ISDN	B-Protocol
for	O
the	O
public	O
switched	O
telephone	O
network	O
.	O
</s>
<s>
An	O
SCCP	O
client	O
uses	O
TCP/IP	B-Protocol
to	O
communicate	O
with	O
one	O
or	O
more	O
Call	O
Manager	O
applications	O
in	O
a	O
cluster	O
.	O
</s>
<s>
It	O
uses	O
the	O
Real-time	B-Protocol
Transport	I-Protocol
Protocol	I-Protocol
(	O
RTP	O
)	O
over	O
UDP-transport	O
for	O
the	O
bearer	O
traffic	O
(	O
real-time	O
audio	O
stream	O
)	O
with	O
other	O
Skinny	O
clients	O
or	O
an	O
H.323	B-Protocol
terminal	O
.	O
</s>
<s>
Cisco	O
also	O
has	O
marketed	O
a	O
Skinny-based	O
softphone	B-Protocol
called	O
Cisco	O
IP	O
Communicator	O
.	O
</s>
<s>
Examples	O
of	O
SCCP	O
client	O
devices	O
include	O
the	O
Cisco	O
7900	O
series	O
of	O
IP	O
phones	O
,	O
Cisco	O
IP	O
Communicator	O
softphone	B-Protocol
,	O
and	O
the	O
802.11b	O
wireless	O
Wireless	O
IP	O
Phone	O
7920	O
,	O
along	O
with	O
Cisco	O
Unity	O
voicemail	O
server	O
.	O
</s>
<s>
Other	O
companies	O
,	O
such	O
as	O
Symbol	O
Technologies	O
,	O
SocketIP	O
,	O
and	O
Digium	B-Protocol
,	O
have	O
implemented	O
the	O
protocol	O
in	O
VoIP	B-Application
terminals	O
and	O
IP	O
phones	O
,	O
media	B-Protocol
gateway	I-Protocol
controllers	I-Protocol
,	O
and	O
softswitches	B-Device
.	O
</s>
<s>
An	O
open	O
source	O
implementation	O
of	O
a	O
call	O
agent	O
is	O
available	O
in	O
the	O
Asterisk	B-Language
and	O
FreeSWITCH	B-Language
systems	O
.	O
</s>
<s>
IPBlue	O
provides	O
a	O
soft	B-Protocol
phone	I-Protocol
that	O
emulates	O
a	O
Cisco	O
7960	O
telephone	O
.	O
</s>
<s>
Twinlights	O
Software	O
distributes	O
a	O
soft	B-Protocol
phone	I-Protocol
implementation	O
for	O
Android-based	O
devices	O
.	O
</s>
