<s>
IP	B-General_Concept
SLA	I-General_Concept
(	O
Internet	O
Protocol	O
Service	O
Level	O
Agreement	O
)	O
is	O
an	O
active	O
computer	B-Architecture
network	I-Architecture
measurement	O
technology	O
that	O
was	O
initially	O
developed	O
by	O
Cisco	O
Systems	O
.	O
</s>
<s>
IP	B-General_Concept
SLA	I-General_Concept
was	O
previously	O
known	O
as	O
Service	B-General_Concept
Assurance	I-General_Concept
Agent	I-General_Concept
(	O
SAA	O
)	O
or	O
Response	O
Time	O
Reporter	O
(	O
RTR	O
)	O
.	O
</s>
<s>
IP	B-General_Concept
SLA	I-General_Concept
is	O
used	O
to	O
track	O
network	B-Architecture
performance	O
like	O
latency	O
,	O
ping	B-Protocol
response	O
,	O
and	O
jitter	O
,	O
it	O
also	O
helps	O
us	O
to	O
provide	O
service	O
quality	O
.	O
</s>
<s>
The	O
exact	O
number	O
and	O
types	O
of	O
available	O
measurements	O
depends	O
on	O
the	O
IOS	B-Protocol
version	O
.	O
</s>
<s>
IP	B-General_Concept
SLA	I-General_Concept
is	O
very	O
widely	O
used	O
in	O
service	O
provider	O
networks	O
to	O
generate	O
time-based	O
performance	O
data	O
.	O
</s>
<s>
It	O
is	O
also	O
used	O
together	O
with	O
Simple	B-Protocol
Network	I-Protocol
Management	I-Protocol
Protocol	I-Protocol
(	O
SNMP	B-Protocol
)	O
and	O
NetFlow	B-Protocol
,	O
which	O
generate	O
volume-based	O
data	O
.	O
</s>
<s>
For	O
IP	B-General_Concept
SLA	I-General_Concept
tests	O
,	O
devices	O
with	O
IP	B-General_Concept
SLA	I-General_Concept
support	O
are	O
required	O
.	O
</s>
<s>
IP	B-General_Concept
SLA	I-General_Concept
is	O
supported	O
on	O
Cisco	O
routers	B-Protocol
and	O
switches	O
since	O
IOS	B-Protocol
version	O
12.1	O
.	O
</s>
<s>
Other	O
vendors	O
like	O
Juniper	O
Networks	O
or	O
Enterasys	O
Networks	O
support	O
IP	B-General_Concept
SLA	I-General_Concept
on	O
some	O
of	O
their	O
devices	O
.	O
</s>
<s>
IP	B-General_Concept
SLA	I-General_Concept
tests	O
and	O
data	O
collection	O
can	O
be	O
configured	O
either	O
via	O
a	O
console	O
(	O
command-line	B-Application
interface	I-Application
)	O
or	O
via	O
SNMP	B-Protocol
.	O
</s>
<s>
When	O
using	O
SNMP	B-Protocol
,	O
both	O
read	O
and	O
write	O
community	O
strings	O
are	O
needed	O
.	O
</s>
<s>
The	O
IP	B-General_Concept
SLA	I-General_Concept
voice	O
quality	O
feature	O
was	O
added	O
starting	O
with	O
IOS	B-Protocol
version	O
12.3(4 )	O
T	O
.	O
All	O
versions	O
after	O
this	O
,	O
including	O
12.4	O
mainline	O
,	O
contain	O
the	O
MOS	O
and	O
ICPIF	O
voice	O
quality	O
calculation	O
for	O
the	O
UDP	O
jitter	O
measurement	O
.	O
</s>
<s>
A	O
software	O
tool	O
is	O
required	O
in	O
order	O
to	O
plot	O
IP	B-General_Concept
SLA	I-General_Concept
test	O
results	O
,	O
which	O
are	O
available	O
from	O
various	O
vendors	O
,	O
including	O
ProLAN	O
,	O
infosim	O
,	O
Watch4Net	O
,	O
Hewlett-Packard	O
,	O
SevOne	O
,	O
and	O
NETvisor	O
.	O
</s>
