Figure 3: Distributed MultiLink Trunking
across stack for higher bandwidth
and fault tolerance
IEEE P802.3af draft-compliant
The BayStack 460-24T-PWR Switch is
IEEE P802.3af draft-compliant. It can
provide Power over Ethernet to any IEEE
P802.3af draft-compliant devices such as IP
phones, wireless access points, net cameras,
security and lighting devices, and access
control devices. The benefit of being inter-
operable with standards-based equipment
means that customers are not forced to
tie themselves to any one vendor, as the
switch has the flexibility to power multiple
vendors’ devices. It can supply power up to
15.4 watts per port, which meets the IEEE
P802.3af standard. This is more than suffi-
cient to power most devices. The standard
is expected to be ratified in Q3, 2003.
Auto discovery feature
The BayStack 460-24T-PWR Switch auto-
matically recognizes the connection of a
device and immediately sends power to it.
This automatic capability ensures fast
connectivity without manual intervention.
Dynamic power management
Each port can be configured to limit the
power delivered to a device. Each port can
also be configured for power priority level—
Low, High, and Critical. On the switch,
total available power is monitored. In the
case where all available power is fully utilized,
the switch may turn off lower priority ports
and turn on higher priority ports.
Active circuit protection
The BayStack 460 Switch can automatically
disable a port if there is a short. All the
other ports on the switch will remain
active and will not be affected by the
disabled port.
Plug-n-Play IP telephony
switching
The BayStack 460 Switch provides simplified
Web-based configurations on data and
power properties. The graphical user
interfaces make it simple to set up data
and power configurations.
Convenience of a single cable
With the BayStack 460 Switch, data and
power can be transmitted over one cable
without using a power outlet. There is no
need for a separate cable connecting the
IP device to a power outlet.
Significant space and
cost savings
Traditionally, a mid-span patch panel
device connects to a standard Ethernet
switch and the device sends power over
standard UTP cat 5 cable. In essence, two
units are needed for Power over Ethernet
capability. In contrast, the BayStack 460
Switch integrates standard LAN switch
functionality with the power over UTP
cable capability of a mid-span patch panel
into one unit. This results in significant
cost and space savings.
Fail-safe stacking
and resiliency
A key differentiation for the BayStack 460
Switch is its resilient stacking feature. The
BayStack 460 Switch can stack up to eight
units with a cascade stacking design, assur-
ing continuous uptime even if a switch in
the stack should fail. A loop-back—or
redundant cascade cable—is used to seam-
lessly connect the entire stack to eliminate
any single point of failure (Figure 2).
MultiLink Trunking
MultiLink Trunking (MLT) enables group-
ing of links between the switch and another
switch or a server to provide greater band-
width with active redundant links.
With Nortel Networks unique Distributed
MultiLink Trunking (DMLT) feature,
trunked ports can span multiple units of
the stack for fail-safe connectivity to mission-
critical servers and the network center
(Figure 3). This can provide bandwidth of up
to 800 Mbps (when used with 10/100 ports)
or up to 8 Gbps (when used with Gigabit
uplink ports) with active redundant links in
one trunk. Up to six trunks are supported
per switch or stack.
Split MultiLink Trunking (SMLT) eliminates
single points of failure and allows wiring
closet switches, such as the BayStack 460,
to have multiple active connections to the
network core. The BayStack 460 Switch’s
ability to have multiple connections to a
2
Figure 2: In the unlikely event of a
switch failure, the stack
integrity is maintained:
cascade signals loop back
at point of failure.
U
nit 8
Unit 7
Unit 6
Unit 5
Unit 4
Unit 3
Unit 2
Unit 1
Multi-Gigabit
load-balancing
and failover
protection for
uninterrupted
access to the
network center
BayStack 460-24T-PWR Switch Stack
Passport 8600 Switch Server
