R&M Data Center Handbook

www.datacenter.rdm.com
All optical signals consist of a wavelength range. Though
this spectrum may only amount to a fraction of a
nanometer, a limited spectral range always exists. The
spreading of the pulse (dispersion) in a fiber is based
approximately on the square of the spectral width. This
effect, in combination with the additional jitters is the
reason for the shorter maximum lengths of OM3 and
OM4 fibers.
Total system costs for optical cabling are significantly
reduced as a result of the specifications being relaxed,
but to the detriment of link lengths and permitted insertion
losses. While maximum losses of 2.6 dB over OM3 were
permitted in the 10GBASE-SR application, these dwindle
down to only 1.9 dB, or 1.5 dB for OM4, in 40GBASE-SR4
and 100GBASE-SR10 applications. (see tables further
below)
Planners, installers and users must be aware that selecting a provider like R&M, whose products guarantee
minimal optical losses, is crucial for the performance of the next generation of fiber optic networks.
The great success of Ethernet up to the present day can be traced back to the affordability, reliability, ease of use
and scalability of the technology. For these reasons, most network traffic these days begins and ends its trip on
Ethernet. Since the computing power of applications grows slower than data traffic as networks are aggregated,
the development of 40 and 100 gigabit Ethernet came at just the right time to allow the Ethernet to continue its
triumphant march. This is because these high speeds provide that technology a perspective for the next years in
companies, in data centers and also in increasing numbers of carrier networks.
Ethernet Applications for Copper Cables with Cat.5, Cat.6 & Cat.6 A
Category & Class acc. ISO/IEC 11801 Cat.5 - Class D Cat.6 - Class E Cat.6 A - Class E A
IEEE 802.3ab - 1000BASE-T
Installation cable
AWG Wire type
shielded &
unshielded
shielded &
unshielded
shielded &
unshielded
Topology PL + Channel* PL + Channel* PL + Channel*
26 Solid 60 m 70 m 55 m 65 m 55 m 65 m
26 Flexible 60 m 70 m 55 m 65 m 55 m 65 m
24 Solid 90 m 100 m
23 Solid 90 m 100 m 90 m 100 m
22 Solid 90 m 100 m 90 m 100 m
IEEE 802.3an - 10GBASE-T
26 Solid 65 m° 55 m 65 m
26 Flexible 65 m° 55 m 65 m
24 Solid
23 Solid 100 m° 90 m 100 m
22 Solid 90 m 100 m
* Channel calculation based on 2x5m patch cord (flexible)
+
Permanent link and channel length reduction if patch cord (flexible cable) >10m
° Cable tested up to 450MHz
10GBase-T, 10 gigabit data transmission for copper cables, was standardized in the summer of 2006. It allows for
use of a 4-pair cable (transmission on all 4 pairs) and a segment length of 100 m.
There is a “higher speed study group” for 40GBase-T and 100GBase-T, which allows 40 Gbit/s over copper
cables, at this point only over 10 m via Twinax cables or 1 m via backplane. However, a 40GBase-T standard is
expected, but is rather doubtful for 100Base-T.
Page 100 of 156 © 08/2011 Reichle & De-Massari AG R&M Data Center Handbook V2.0