Specifications

22 ExtremeWare XOS 11.0 Concepts Guide
ExtremeWare XOS Overview
Implementing VLANs on your network has the following three advantages:
• Helps to control broadcast traffic. If a device in VLAN Marketing transmits a broadcast frame, only
VLAN Marketing devices receive the frame.
• Provides extra security. Devices in VLAN Marketing can communicate only with devices on VLAN
Sales using routing services.
• Eases the change and movement of devices on networks.
For more information on VLANs, see Chapter 5.
Spanning Tree Protocol
The switch supports the IEEE 802.1D Spanning Tree Protocol (STP), which is a bridge-based mechanism
for providing fault tolerance on networks. STP enables you to implement parallel paths for network
traffic and to ensure that redundant paths are:
• Disabled when the main paths are operational.
• Enabled if the main traffic paths fail.
A single Spanning Tree Domain (STPD) can span multiple VLANs.
For more information on STP, see Chapter 12.
EAPS
With software version 11.0, the switch supports Ethernet Automatic Protection Switching (EAPS). This
Extreme Networks proprietary protocol provides fast protection switching to Layer 2 devices connected
in a ring topology, such as large campuses. EAPS provides protection to switching similar to STP, but
the convergence is much faster using EAPS. This fast convergence occurs regardless of the number of
switches in the ring.
For more information on EAPS, see Chapter 11.
Quality of Service
ExtremeWare XOS has Policy-Based Quality of Service (QoS) features that enable you to specify service
levels for different traffic groups. By default, all traffic is assigned the low QoS policy profile. If needed,
you can customize other QoS policies and apply these policies to different traffic types so that the traffic
types have different guaranteed minimum bandwidth, maximum bandwidth, and priority.
With software version 11.0, you can set parameters for ingress traffic, called bi-directional rate shaping.
For more information on Quality of Service, see Chapter 8.
Load Sharing
Load sharing allows you to increase bandwidth and resiliency by using a group of ports to carry traffic
in parallel between systems. This feature allows the switch to use multiple ports as a single logical port.
For example, VLANs see the load-sharing group as a single virtual port. Most of the load-sharing
algorithms also guarantee packet sequencing between clients.
For information on load sharing, see Chapter 4.