<s>
The	O
High-Speed	B-Device
Serial	I-Device
Interface	I-Device
(	O
HSSI	B-Device
)	O
is	O
a	O
differential	O
ECL	B-General_Concept
serial	O
interface	O
standard	O
developed	O
by	O
Cisco	O
Systems	O
and	O
T3plus	O
Networking	O
primarily	O
for	O
use	O
in	O
WAN	O
router	B-Protocol
connections	O
.	O
</s>
<s>
While	O
HSSI	B-Device
uses	O
50-pin	O
connector	O
physically	O
similar	O
to	O
that	O
used	O
by	O
SCSI-2	O
,	O
it	O
requires	O
a	O
cable	O
with	O
an	O
impedance	O
of	O
110Ω	O
(	O
as	O
opposed	O
to	O
the	O
75Ω	O
of	O
a	O
SCSI-2	O
cable	O
)	O
.	O
</s>
<s>
It	O
is	O
supported	O
by	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
since	O
version	O
3.4-rc2	O
.	O
</s>
