Using 802.1p Priority to Provide QoS

BLADEOS 6.5.2 Application Guide

The G8124 provides Quality of Service functions based on the priority bits in a packet’s VLAN header. (The priority bits are defined by the 802.1p standard within the IEEE 802.1Q VLAN header.) The 802.1p bits, if present in the packet, specify the priority that should be given to packets during forwarding. Packets with a numerically higher (non-zero) priority are given forwarding preference over packets with lower priority value.

The IEEE 802.1p standard uses eight levels of priority (0-7). Priority 7 is assigned to highest priority network traffic, such as OSPF or RIP routing table updates, priorities 5-6 are assigned to delay-sensitive applications such as voice and video, and lower priorities are assigned to standard applications. A value of 0 (zero) indicates a “best effort” traffic prioritization, and this is the default when traffic priority has not been configured on your network. The switch can filter packets based on the 802.1p values.

Figure 16 Layer 2 802.1q/802.1p VLAN tagged packet

Preamble

SFD

DMAC

SMAC

Tag

E Type Data

FCS


	Priority							VLAN		Identifier		(VID)

7	6	5	4	3	2	1	0	7	6		5		4	3	2	1	0

Ingress packets receive a priority value, as follows:

Tagged packets—switch reads the 802.1p priority in the VLAN tag.

Untagged packets—switch tags the packet and assigns an 802.1p priority value, based on the port’s default 802.1p priority.

Egress packets are placed in a COS queue based on the priority value, and scheduled for transmission based on theCOS queue number. Higher COS queue numbers provide forwarding precedence.

To configure a port’s default 802.1p priority value, use the following commands.

RS G8124(config)# interface port 1

RS G8124(config-if)# dot1p <802.1p value (0-7)>

142 Chapter 9: Quality of Service

BMD00220, October 2010

G8124-E, G8124 specifications

The Blade ICE G8124 is a cutting-edge networking solution designed for high-performance data center environments. It has emerged as a popular choice among organizations that require reliable and efficient network infrastructure to support their growing demands for bandwidth and low-latency connectivity.

One of the key features of the Blade ICE G8124 is its high port density. This networking device typically offers 24 ports of 10 Gigabit Ethernet, ensuring that businesses can connect numerous devices without requiring extensive physical space. The design is also scalable, accommodating future expansion as organizational needs grow.

Another significant aspect of the G8124 is its advanced switching capabilities. It utilizes a non-blocking architecture, enabling simultaneous data transmissions on all ports. This characteristic ensures that there is no bottleneck in the network traffic, providing the high performance needed in data-intensive applications.

The G8124 incorporates various technologies to enhance its functionalities. It supports Layer 2 and Layer 3 switching, making it versatile for different networking needs. Additionally, it features comprehensive Quality of Service (QoS) settings that prioritize critical applications, such as VoIP and video streaming, ensuring smooth operation even under heavy loads.

In terms of security, the Blade ICE G8124 provides robust measures to protect the network. It supports features such as Access Control Lists (ACLs), port security, and VLANs, allowing administrators to segment the network and restrict unauthorized access. These security capabilities are vital in today’s landscape, where cyber threats are increasingly common.

Moreover, the G8124 offers excellent management features. It includes an intuitive user interface for easy configuration and monitoring of network performance. SNMP support allows integration with network management systems, providing administrators with insights needed to optimize their operations.

Power efficiency is also a hallmark of the Blade ICE G8124. It employs energy-saving technologies that reduce operational costs, an essential factor for environmentally-conscious organizations striving to minimize their carbon footprint.

In summary, the Blade ICE G8124 stands out with its high port density, advanced switching capabilities, robust security features, and efficient management options. This networking solution is designed to meet the demands of modern data centers, providing the performance, reliability, and scalability that organizations require. With its innovative technologies, the G8124 ensures that businesses can navigate the complexities of today's networking landscape effectively.