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Extreme Networks Data Sheet:
Summit X250e Series
Technical Specifications
Voice-Class Availability
Modular Operating System for High Availability
Operation
Preemptive Multitasking and Protected Memory
Summit X250e switches allow each of 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 will
not drop and digital video feeds will 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 Extreme Standby
Router Protocol™ (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.
Multi-Switch LAG (M-LAG)
M-LAG can address bandwidth limitations and improve network resiliency,
in part by routing network traffic around bottlenecks, reducing the risks of
a single point of failure, and allowing load balancing across multiple switches.
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, X450e, X450a, X460, X480 and X650 series switches
running the same version of ExtremeXOS) 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).
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• Processes are monitored and can be restarted
or other action taken if necessary
• Hitless failover infrastructure for dual management
systems and stacking
Memory protected
processes under
real-time
scheduling that
cannot impact
each other nor
kernel
1
Designed to allow
application
modules to be
upgraded during
runtime
3
Application
modules can be
added during
runtime
2
SSH-2
V1.3.2
BGP
OSPF
Third
Party
Application
SSH-2
V1.3.1
ExtremeXOS®
Kernel
Kernel Loadable
Module
Figure 1: ExtremeXOS Modular Design
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• Single management point for up to eight units
• High-speed 40 Gbps stacking
• Rapid Failover for converged applications
• Can mix Summit
®
X250e, Summit X450a/e series,
Summit X460, Summit X480 and Summit X650 series switches
for SummitStack™ 40 Gbps stacking
Figure 2: SummitStack Stacking Architecture
