34 4 Features
Reliability
The SysKonnect SK-9E21D 10/100/1000Base-T Adapter, PCI Express, comes with a variety
of reliability features. They aim at maintaining a connection as long as possible. This is
reached by redundant or grouped links (link aggregation). The driver functions help to monitor
the health of adapters and their ports enabling pro-active network management. The reliability
features are described in the following sections.

Link Aggregation

Link aggregation or trunking is a method of combining physical network links into a single log-
ical link for increased bandwidth. With link aggregation, it is possible to increase the capacity
and availability of the communications channel between devices (both switches and end sta-
tions) using existing Fast Ethernet and Gigabit Ethernet technology. Two or more Gigabit
Ethernet connections are combined into a team in order to increase the bandwidth capability
and to create resilient and redundant links. A set of multiple parallel physical links between
two devices is grouped together to form a single logical link. Link aggregation offers an effi-
cient and low-cost solution to increase bandwidth between server and switch. Another advan-
tage it provides is that if a connection fails completely the remaining links can take over the
traffic and thus replace the broken line.
Link aggregation also provides load balancing where the processing and communications ac-
tivity is distributed across several links so that no single link is overwhelmed.
By taking multiple LAN connections and treating them as a unified, aggregated link, practical
benefits can be achieved in many applications.
Link aggregation provides the following important benefits:
• Higher link availability
• Increased link capacity
• Improvements are obtained using existing hardware (no upgrading to higher-capacity link
technology is necessary)
Demanding applications running in high-performance environments like servers in enterpris-
es, web servers, and intranet servers gain particularly from the high-bandwidth and duplex
capabilities of link aggregation.
All SysKonnect Gigabit Ethernet Adapters support link aggregation according to the IEEE
standard 802.3ad. At the moment, SysKonnect provides a link aggregation driver for
Windows 2000, WindowsXP and Windows Server 2003. The drivers for Linux are able to
support link aggregation according to the IEEE standard 802.3ad by installing third party open
source modules. For details, refer to the corresponding readme file. In the future, link aggre-
gation support according to IEEE 802.3ad will be implemented in SysKonnect drivers for oth-
er operating systems as well. For driver updates, refer to our web site: http://
www.syskonnect.com.
For more information on link aggregation, refer to the white paper “Link Aggregation accord-
ing to IEEE 802.3ad”, which can be found on the SysKonnect installation CD-ROM and on our
web site.