<s>
The	O
Message	B-Protocol
Send	I-Protocol
Protocol	I-Protocol
(	O
MSP	O
)	O
is	O
an	O
application	B-Application
layer	I-Application
protocol	O
used	O
to	O
send	O
a	O
short	O
message	O
between	O
nodes	B-Protocol
on	O
a	O
network	B-Architecture
.	O
</s>
<s>
It	O
was	O
updated	O
as	O
Message	B-Protocol
Send	I-Protocol
Protocol	I-Protocol
2	I-Protocol
in	O
1992	O
.	O
</s>
<s>
One	O
message	O
send	O
service	O
is	O
defined	O
as	O
a	O
connection-based	O
application	O
on	O
TCP	B-Protocol
.	O
</s>
<s>
A	O
service	O
listens	O
for	O
TCP	B-Protocol
connections	O
on	O
port	B-Protocol
18	O
.	O
</s>
<s>
Another	O
message	O
send	O
service	O
is	O
defined	O
as	O
a	O
datagram-based	O
application	O
on	O
UDP	B-Protocol
.	O
</s>
<s>
A	O
service	O
listens	O
for	O
UDP	B-Protocol
datagrams	O
on	O
port	B-Protocol
18	O
.	O
</s>
