Chapter 5

Configuring the Switch

Generate  This button is used to generate the host key pair.. Note that you must first generate the host key pair before you can enable the SSH server..

Clear  This button clears the host key from both volatile memory (RAM) and non-volatile memory (Flash)..

QoS

Network traffic is usually unpredictable, and the only basic assurance that can be offered is best effort traffic delivery.. To overcome this challenge, Quality of Service (QoS) is applied throughout the network.. This ensures that network traffic is prioritized according to specified criteria, and that specific traffic receives preferential treatment.. QoS in the network optimizes network performance and entails two basic facilities:

Classifying incoming traffic into handling classes, based on an attribute, including:

•The ingress interface

•Packet content

•A combination of these attributes

Providing various mechanisms for determining the allocation of network resources to different handling classes, including:

•The assignment of network traffic to a particular hardware queue

•The assignment of internal resources

•Traffic shaping

The terms Class of Service (CoS) and QoS are used in the following context:

CoS provides varying Layer 2 traffic services.. CoS refers to classification of traffic to traffic-classes, which are handled as an aggregate whole, with no per-flow settings.. CoS is usually related to the 802..1p service that classifies flows according to their Layer 2 priority, as set in the VLAN header..

QoS refers to Layer 2 traffic and above.. QoS handles per- flow settings, even within a single traffic class..

QoS > CoS Settings

Class of Service (CoS) allows you to specify which data packets have greater precedence when traffic is buffered in the Switch due to congestion.. The Switch supports CoS with four priority queues for each port.. Data packets in a port’s high-priority queue will be transmitted before those in the lower-priority queues.. You can set the default priority for each interface, and configure the mapping of frame priority tags to the Switch’s priority queues..

QoS > Cos Settings

The priority levels recommended in the IEEE 802..1p standard for various network applications are shown in the following table.. However, you can map the priority levels to the Switch’s output queues in any way that benefits application traffic for your own network..

 

Priority Level Mappings

 

 

Priority Level

Traffic Type

 

 

1

Background

2

(Spare)

0

(default) Best Effort

3

Excellent Effort

4

Controlled Load

5Video, less than 100 ms latency and jitter

6Voice, less than 10 ms latency and jitter

7

Network Control

CoS to Queue

Assign priorities to the traffic classes (output queues) for the selected interface..

Class of Service  CoS value.. (Range: 0-7, where 7 is the highest priority queue)

Queue (0-3) The output priority queue.. (Range: 0-3, where 3 is the highest CoS priority queue)

48-Port 10/100 + 4-Port Gigabit Switch with WebView and Power over Ethernet

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Cisco Systems SRW248G4P manual QoS CoS Settings, CoS to Queue
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SRW248G4P specifications

Cisco Systems SRW248G4P is a high-performance Layer 2 switch designed specifically for small to medium-sized businesses that require robust networking solutions. This switch supports Power over Ethernet (PoE), providing a highly flexible option for powering devices such as IP phones, wireless access points, and surveillance cameras.

One of the standout features of the SRW248G4P is its 48 10/100 Ethernet ports, which ensure ample connectivity for various networked devices. Additionally, it offers four Gigabit Ethernet uplink ports, allowing for seamless integration with existing network infrastructure and facilitating high-speed data transfer. The combination of these ports enables businesses to expand their network capabilities as needed without the immediate requirement for added devices.

The SRW248G4P comes equipped with advanced Layer 2 switching capabilities, including VLAN support, which enables the segmentation of network traffic for improved performance and security. It also supports Spanning Tree Protocol (STP) and Rapid Spanning Tree Protocol (RSTP), which help prevent network loops and ensure redundancy. With features like Link Aggregation Control Protocol (LACP), multiple physical connections can be combined into a single logical link, enhancing bandwidth and providing failover capabilities.

Another critical attribute of the Cisco SRW248G4P is its user-friendly management interface. The switch can be managed through a web-based interface, allowing IT administrators to configure settings, monitor performance, and troubleshoot issues with ease. Additionally, it supports SNMP (Simple Network Management Protocol) for integration with network management systems, further simplifying monitoring tasks.

Power over Ethernet functionality is a significant advantage of the SRW248G4P, providing up to 15.4 watts per port. This capability simplifies installation and reduces the clutter of power cords and outlets. Organizations can deploy PoE-enabled devices in locations that lack power sources, thus enhancing overall flexibility in network design.

In summary, the Cisco Systems SRW248G4P is a feature-rich switch tailored for small to medium-sized enterprises. Its blend of performance, management capabilities, and advanced features like PoE makes it a valuable asset in any organization's networking setup. By ensuring reliable connectivity and ease of management, businesses can focus more on growth and their core objectives rather than worrying about network complexities.
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