<s>
Reliable	B-Protocol
Internet	I-Protocol
Stream	I-Protocol
Transport	I-Protocol
(	O
RIST	B-Protocol
)	O
is	O
an	O
open-source	B-License
,	O
open-specification	O
transport	O
protocol	O
designed	O
for	O
reliable	O
transmission	O
of	O
video	O
over	O
lossy	B-Protocol
networks	I-Protocol
(	O
including	O
the	O
Internet	O
)	O
with	O
low	O
latency	O
and	O
high	O
quality	O
.	O
</s>
<s>
It	O
is	O
currently	O
under	O
development	O
in	O
the	O
Video	O
Services	O
Forum	O
's	O
"	O
RIST	B-Protocol
Activity	O
Group.	O
"	O
</s>
<s>
RIST	B-Protocol
is	O
intended	O
as	O
a	O
more	O
reliable	O
successor	O
to	O
Secure	B-Protocol
Reliable	I-Protocol
Transport	I-Protocol
,	O
and	O
as	O
an	O
open	O
alternative	O
to	O
proprietary	O
commercial	O
options	O
such	O
as	O
Zixi	O
,	O
VideoFlow	O
,	O
QVidium	O
,	O
and	O
DVEO	O
(	O
Dozer	O
)	O
.	O
</s>
<s>
Technically	O
,	O
RIST	B-Protocol
seeks	O
to	O
provide	O
reliable	O
,	O
high	O
performance	O
media	O
transport	O
by	O
using	O
RTP	B-Protocol
/	O
UDP	B-Protocol
at	O
the	O
transport	O
layer	O
to	O
avoid	O
the	O
limitations	O
of	O
TCP	B-Protocol
.	O
</s>
<s>
Reliability	O
is	O
achieved	O
by	O
using	O
NACK-based	O
retransmissions	O
(	O
ARQ	B-Error_Name
)	O
.	O
</s>
<s>
SMPTE-2022	O
Forward	B-Error_Name
Error	I-Error_Name
Correction	I-Error_Name
can	O
be	O
combined	O
with	O
RIST	B-Protocol
but	O
is	O
known	O
to	O
be	O
significantly	O
less	O
effective	O
than	O
ARQ	B-Error_Name
.	O
</s>
<s>
RIST	B-Protocol
Simple	O
Profile	O
was	O
published	O
in	O
October	O
2018	O
and	O
includes	O
the	O
following	O
features	O
:	O
</s>
<s>
The	O
base	O
stream	O
uses	O
RTP	B-Protocol
for	O
compatibility	O
with	O
existing	O
equipment	O
.	O
</s>
<s>
Retransmission	O
requests	O
use	O
RTCP	B-Protocol
.	O
</s>
<s>
A	O
Range	O
NACK	O
,	O
defined	O
as	O
an	O
APP	O
RTCP	B-Protocol
packet	O
.	O
</s>
<s>
Bonding	B-Architecture
of	O
multiple	O
links	O
for	O
load	O
sharing	O
.	O
</s>
<s>
The	O
RIST	B-Protocol
AG	O
is	O
working	O
on	O
an	O
update	O
to	O
RIST	B-Protocol
Simple	O
Profile	O
that	O
adds	O
link	O
probing	O
to	O
allow	O
for	O
dynamic	O
ARQ	B-Error_Name
protection	O
.	O
</s>
<s>
RIST	B-Protocol
Main	O
Profile	O
was	O
published	O
in	O
March	O
2020	O
and	O
adds	O
the	O
following	O
features	O
to	O
Simple	O
Profile	O
:	O
</s>
<s>
DTLS	B-Protocol
encryption	O
.	O
</s>
<s>
Advanced	O
authentication	O
options	O
using	O
either	O
public	O
key	O
certificates	O
or	O
TLS-SRP	B-Protocol
.	O
</s>
<s>
Support	O
for	O
high	O
bit-rate	O
streams	O
by	O
extending	O
the	O
RTP	B-Protocol
sequence	B-Protocol
number	I-Protocol
.	O
</s>
<s>
The	O
RIST	B-Protocol
AG	O
has	O
defined	O
a	O
number	O
of	O
Main	O
Profile	O
compliance	O
levels	O
.	O
</s>
<s>
RIST	B-Protocol
Enhanced	O
Profile	O
is	O
currently	O
under	O
development	O
.	O
</s>
<s>
:	O
an	O
open-source	B-License
RIST	B-Protocol
implementation	O
that	O
includes	O
both	O
Simple	O
and	O
Main	O
Profiles	O
.	O
</s>
