Extreme Networks 15101 Voice-Class Availability, High Availability Network Protocols, ExtremeXOS

Extreme Networks Data Sheet

Voice-Class Availability  

Powered by the ExtremeXOS operating system, the Summit X250e switch supports process recovery and application upgrades without the need for a system reboot. Summit X250e offers the high network availability required for converged applications.

Modular Operating System for High Availability Operation

True Preemptive Multitasking and Protected Memory

Summit X250e switches allow each of the many applications—such as Open Shortest Path First (OSPF) and Spanning Tree Protocol (STP)—to run as separate Operating System (OS) processes that are protected from each other. This drives increased system integrity and helps protect against Denial of Service (DoS) attacks.

Process Monitoring and Restart

ExtremeXOS improves network availability using process monitoring and restart. Each independent OS process is monitored in real time. If a process becomes unresponsive or stops running, it can be automatically restarted.

Loadable Software Modules

The modular design of the ExtremeXOS OS allows the upgrading of individual software modules, should this be necessary, leading to higher availability in the network (see Figure 1).

High Availability

Network Protocols

Ethernet Automatic Protection Switching (EAPS)

EAPS allows the IP network to provide the level of resiliency and uptime that users expect from their traditional voice network. EAPS differs from Spanning Tree or Rapid Spanning Tree protocols and offers sub-second (less than 50

milliseconds) recovery that helps deliver consistent failover regardless of the number of VLANs, network nodes or network topology. Since EAPS allows the network to recover almost transparently, VoIP calls do not drop and digital video feeds do not freeze or pixelize in most situations.

Spanning Tree/Rapid Spanning Tree Protocols

Summit X250e switches support Spanning Tree (802.1D), Per VLAN Spanning Tree (PVST+), Rapid Spanning Tree (802.1w) and Multiple Instances of Spanning Tree (802.1s) protocols for Layer 2 resiliency.

Software-Enhanced Availability

Software-enhanced availability allows users to remain connected to the network even if part of the network infrastructure is down. Summit X250e switches continuously check for problems in the uplink connections using advanced Layer 3 protocols such as OSPF, VRRP and ESRP (ESRP supported in Layer 2 or Layer 3), and dynamically route traffic around the problem.

Equal Cost Multipath Routing

Equal Cost Multipath (ECMP) routing allows uplinks to be load balanced for performance and cost savings while also supporting redundant failover. If an uplink fails, traffic is automatically routed to the remaining uplinks and connectivity is maintained.

Link Aggregation (802.3ad)

Link aggregation allows trunking of up to eight links on a single logical connection, for up to 2 Gigabits per Second (Gbps) of redundant bandwidth per logical connection.

Voice-Grade Stacking with SummitStack

Summit X250e offers dual stacking interfaces to provide high-speed 40 Gbps stacking bandwidth. SummitStack architecture is designed to support converged services by its highly available, rapid failover capability with n-1 master redundancy, distributed Layer 2 and Layer 3 switching, link aggregation across the stack and distributed uplinks. SummitStack supports up to eight units in a stack (the mixture of the units can be Summit X250e, Summit X450e, Summit X450a, Summit X480 and Summit X650 switches) and provides sub-second failover for path failure and hitless master/backup failover along with hitless protocol support such as OSPF graceful restart, PoE configuration and Network Login user authentication.

Summit X250e provides chassis-like management and availability with its SummitStack stacking technology (see Figure 2).

Figure 2: SummitStack Stacking

Architecture

1 Updated application
modules can be	PIM-SM	PIM-DM
upgraded during runtime
	V4.6	V4.4

ExtremeXOS	Application	PIM-SM	PIM-DM
	Kernel Loadable	Kernel
	Modules	V4.5	V4.5
	Kernel and	ExtremeXOS
	Modules

2New Extreme Networks or external application modules can be added during runtime

SSG-2 +

SCP

Third

Party

Application

Kernel Loadable

Module

5154-01

Figure 1: ExtremeXOS Modular Design

© 2010 Extreme Networks, Inc. All rights reserved. Summit X250e Series—Page 2