Multi-Link Trunking - Nortel BayStack 425-48T Brochure

stackable with itself and BayStack 425-24T Switches in a future software release. Currently,
BayStack 425-24T and BayStack 420-24T Switches can be stacked in any combination up to a
maximum of eight units.
Flexible high-speed uplink ports
The BayStack 425 Switches offer two built-in combo uplink ports (ports 25 and 26 of BayStack
425-24T and ports 49 and 50 of the BayStack 425-48T) in the front of the unit that provide
high-speed connection to backbone switches or servers. Each combo port consists of one SFP
(Small Form Factor Pluggable) GBIC (Gigabit Interface Converter) uplink port and one
10/100/1000BASE-T port (Figure 5). Each combo port autosenses between the SFP and the
10/100/1000BASE-T port. When the stacking ports are being used for stacking on the
BayStack 425-24T Switch, combo port 26 is automatically turned off. When the stacking
feature becomes available for BayStack 425-48T, combo port 50 will be automatically turned
off. In a stack of eight BayStack 425 Switches, up to 8 uplink ports can be used.
Wire-speed throughput
A 16 Gigabit per second (Gbps) switching fabric and ASICS support full 802.1d-compliant
MAC Layer frame forwarding and filtering across all ports at wire-speed performance. The
BayStack 425-24T Switch has a peak forwarding rate of 6.6 million packets per second and the
BayStack 425-48T Switch has a peak forwarding rate of 10.1 million packets per second.
BoSS (BayStack operating system Switching Software)
BoSS for BayStack 425 Switches is a single software image that is used for BayStack 425-24T,
BayStack 420-24T, and BayStack 425-48T switches. Future versions provide new features
and will be available for free for the lifetime of the
switches. Other BayStack switches support a different
version of BoSS.
BoSS version 3.1 is currently available from
www.nortelnetworks.com/support and adds
support for the following features:
• Support for BayStack 425-48T
• 255 VLANs support (BayStack 425 only)
• Custom Auto Negotiation Advertisements (CANA)
Flexible stacking across BayStack 425 and 420 Switches
The BayStack 425-24T Switch can be stacked with the BayStack 420-24T Switch. A maximum
of eight switches can be stacked together in any combination. BayStack 425-48T Switch will be
able to stack with BayStack 425-24T Switch in a future software release.
Simplified network operations
BoSS simplifies network operations by reducing the number of steps required for switch soft-
ware updates. With BoSS, only a single image needs to be downloaded from Nortel Networks
Web site for all BayStack 425 and 420 Switches. Loading the image to different switches is also
considerably simplified. The image is loaded only to the base unit of the stack, which automati-
cally loads it to other switches in the stack.

Multi-Link Trunking

Multi-Link Trunking (MLT) enables grouping of links between a BayStack 425 Switch and
another switch or a server to provide greater bandwidth with active redundant links. Nortel
Networks unique Distributed Multi-Link Trunking (DMLT) feature allows trunked ports to
span multiple units of the stack for redundant connectivity to mission-critical servers and the
network center (Figure 4). The BayStack 425 Switches support up to 6 MLTs per switch or
stack with up to 4 ports per MLT.
Combo
Combo
Port 26
Port 25
Figure 4. The plug-and-play
architecture allows easy expansion,
and management as a single unit
Figure 5. Each combo port auto-
senses between 1 SFP uplink port
and 1 10/100/1000BASE-T port
3