EDS-408A/405A Series User’s Manual

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yIEEE 802.1D—a layer 2 marking scheme.

yDifferentiated Services (DiffServ)—a layer 3 marking scheme.

IEEE 802.1D Traffic Marking

The IEEE Std 802.1D, 1998 Edition marking scheme, which is an enhancement to IEEE Std 802.1D, enables Quality of Service on the LAN. Traffic service levels are defined in the IEEE 802.1Q 4-byte tag, which is used to carry VLAN identification as well as IEEE 802.1p priority information. The 4-byte tag immediately follows the destination MAC address and Source MAC address.

The IEEE Std 802.1D, 1998 Edition priority marking scheme assigns an IEEE 802.1p priority level between 0 and 7 to each frame. This determines the level of service that type of traffic should receive. Refer to the table below for an example of how different traffic types can be mapped to the eight IEEE 802.1p priority levels.

IEEE 802.1p Priority Level

IEEE 802.1D Traffic Type

0

Best Effort (default)

1

Background

2

Standard (spare)

3

Excellent Effort (business critical)

4

Controlled Load (streaming multimedia)

5

Video (interactive media); less than 100 milliseconds

 

of latency and jitter

6

Voice (interactive voice); less than 10 milliseconds of

 

latency and jitter

7

Network Control Reserved traffic

Even though the IEEE 802.1D standard is the most widely used prioritization scheme in the LAN environment, it still has some restrictions:

yIt requires an additional 4-byte tag in the frame, which is normally optional in Ethernet networks. Without this tag, the scheme cannot work.

yThe tag is part of the IEEE 802.1Q header, so to implement QoS at layer 2, the entire network must implement IEEE 802.1Q VLAN tagging.

It is only supported on a LAN and not across routed WAN links, since the IEEE 802.1Q tags are removed when the packets pass through a router.

Differentiated Services (DiffServ) Traffic Marking

DiffServ is a Layer 3 marking scheme that uses the DiffServ Code Point (DSCP) field in the IP header to store the packet priority information. DSCP is an advanced intelligent method of traffic marking because you can choose how your network prioritizes different types of traffic. DSCP uses 64 values that map to user-defined service levels, allowing you to establish more control over network traffic.

Advantages of DiffServ over IEEE 802.1D are:

yConfigure how you want your switch to treat selected applications and types of traffic by assigning various grades of network service to them.

yNo extra tags are required in the packet.

yDSCP uses the IP header of a packet and therefore priority is preserved across the Internet.

yDSCP is backward compatible with IPV4 TOS, which allows operation with existing devices that use a layer 3 TOS enabled prioritization scheme.

Traffic Prioritization

The EDS classifies traffic based on layer 2 of the OSI 7 layer model, and the switch prioritizes received traffic according to the priority information defined in the received packet. Incoming

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Moxa Technologies EDS-405A, EDS-408A user manual Ieee 802.1p Priority Level Ieee 802.1D Traffic Type, Traffic Prioritization
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EDS-405A, EDS-408A specifications

Moxa Technologies has established itself as a leader in networking solutions, particularly for industrial applications. Among their cutting-edge products is the 405A Series, specifically the EDS-408A model, which exemplifies Moxa's commitment to performance, reliability, and versatility in industrial Ethernet switches.

The EDS-408A is an 8-port industrial Ethernet switch that offers an impressive array of features and capabilities designed to meet the demands of harsh environments. One of its main highlights is the ability to support both 10/100 Mbps Fast Ethernet and Gigabit Ethernet connections, providing users with the flexibility to integrate a range of devices within their network. Its robust design ensures that it operates seamlessly in extreme conditions, with a wide operating temperature range from -40 to 75 degrees Celsius.

The EDS-408A is built to support an array of networking topologies. It features advanced Ethernet switching technologies that enable fast and efficient data transfer while minimizing latency. The device is equipped with wire-speed forwarding capabilities, which is vital for maintaining high performance in heavy network traffic scenarios.

Another key feature of the EDS-408A is its redundancy support. The switch incorporates various redundancy protocols, including Rapid Spanning Tree Protocol (RSTP) and MRP (Media Redundancy Protocol), which enhance network reliability by allowing quick recovery in the event of a failure. This ensures continuous network uptime, which is critical for industrial applications.

Furthermore, Moxa Technologies has adopted an user-friendly web-based management interface in the EDS-408A, simplifying the configuration and monitoring process. This allows system administrators to easily manage settings, monitor traffic, and troubleshoot issues in real time. Additionally, the switch supports SNMP (Simple Network Management Protocol) for remote monitoring and management, enabling organizations to keep their networks optimized.

Security is another paramount feature of the EDS-408A. It includes built-in security mechanisms such as port security, VLAN, and access control lists (ACLs), which help safeguard sensitive network segments from unauthorized access.

In conclusion, Moxa Technologies' EDS-408A model from the 405A Series is a robust and feature-rich industrial Ethernet switch designed for demanding environments. With its support for various network protocols, redundancy features, user-friendly management, and enhanced security, the EDS-408A stands out as a reliable solution for organizations looking to enhance their industrial networking capabilities.
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