Xrn Overview; Major Technologies; Typical Networking Topology - 3Com 5500-SI Configuration Manual

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XRN Overview

Major Technologies

Typical Networking
Topology
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Table 3 Models in the Switch 5500 family (continued)
Power
supply unit
Model (PSU)
AC-input,
5500G-EI
PWR 48-Port
DC-input
5500G-EI AC-input,
24-Port SFP
DC-input
The Switch 5500 family
Internet broadband access
■
MAN (metropolitan area network), enterprise/campus networking
■
Multicast service, multicast routing, and audio and video multicast service.
■
With the XRN (eXpandable Resilient Networking) feature, you can connect several
devices into a combined device and manage them as a single unit. The combined
device is called the Fabric, while the member devices are units. With XRN you can:
Manage multiple devices in centralized manner, with low management cost.
■
Extend the number of ports and switching capacity just by adding devices. You can
■
decide which equipment to purchase as needed, and better protect your existing
investment while upgrading the network.
Provide backup between multiple devices to improve reliability and to eliminate
■
single points of failure.
XRN includes three technologies: distributed device management (DDM), distributed
link aggregation (DLA), and distributed resilient route (DRR).
DDM: Users can treat the Fabric as a single device. They can manage the Fabric
■
through any port or IP address connected into the Fabric, and from any unit in the
fabric.
DRR: The multiple units of a Fabric route and forward packets as a single unit, and
■
provide uniform VLAN interfaces, routing table and L3 forwarding table, so the
Fabric is regarded as a single Layer 3 switch. Failure of one of the units will not
affect routing protocol and data forwarding.
DLA: Users can aggregate multiple ports of several different units in a Fabric into a
■
group, for centralized management within the Fabric. Trans-unit link aggregation
can bring convenient aggregation setting and effectively reduce single points of
failure.
The Switch 5500-SI supports basic XRN, that is DDM and DLA; the Switch 5500-EI
supports enhanced XRN, including DDM, DRR, and DLA.
Typical XRN networking topology is as shown in Figure 1. Switches of the same type
(that is, units) form a Fabric. As a core switch, the Fabric can be downlinked to
workgroup switches through several aggregation links, and uplinked to the server
group also through several aggregation links.
Number of
service Number of 100
ports Mbps ports
48 —
24 —
supports the following services:
Number of 1000
Mbps uplink Console
ports port
44 10/100/1000 1
Mbps plus 4
10/100/1000 or SFP
20 10/100/1000 1
Mbps plus 4
10/100/1000 or SFP