Ieee 802.1Q CoS and IP ToS Queuing, 16-4

Chapter 16 CE-100T-8 Ethernet Operation

CE-100T-8 Ethernet Features

Note Some network devices can be configured to ignore a loss of carrier condition. If a device configured to ignore a loss of carrier condition attaches to a CE-100T-8 card at one end, alternative techniques (such as use of Layer 2 or Layer 3 keep-alive messages) are required to route traffic around failures. The response time of such alternate techniques is typically much longer than techniques that use link state as indications of an error condition.

IEEE 802.1Q CoS and IP ToS Queuing

The CE-100T-8 references IEEE 802.1Q class of service (CoS) thresholds and IP type of service (ToS) (IP Differentiated Services Code Point [DSCP]) thresholds for priority queueing. CoS and ToS thresholds

for the CE-100T-8 are provisioned on a per port level. This allows the user to provide priority treatment based on open standard quality of service (QoS) schemes already existing in the data network attached to the CE-100T-8. The QoS treatment is applied to both Ethernet and POS ports.

Any packet or frame with a priority greater than the set threshold is treated as priority traffic. This priority traffic is sent to the priority queue instead of the normal queue. When buffering occurs, packets on the priority queue preempt packets on the normal queue. This results in lower latency for the priority traffic, which is often latency-sensitive traffic, such as VoIP.

Because these priorities are placed on separate queues, the priority queuing feature should not be used to separate rate-based CIR/EIR marked traffic (sometimes done at a Metro Ethernet service provider edge). This could result in out-of-order packet delivery for packets of the same application, which would cause performance issues with some applications.

For an IP ToS-tagged packet, the CE-100T-8 can map any of the 256 priorities specified in IP ToS to priority or best effort. The user can configure a different ToS on CTC at the card-level view under the Provisioning > Ether Ports tabs. Any ToS class higher than the class specified in CTC is mapped to the priority queue, which is the queue geared towards low latency. By default, the ToS is set to 255, which is the highest ToS value. This results in all traffic being treated with equal priority by default.

Table 16-3shows which values are mapped to the priority queue for sample IP ToS settings. (ToS settings span the full 0 to 255 range, but only selected settings are shown.)

Table 16-1 IP ToS Priority Queue Mappings

ToS Setting in CTC	ToS Values Sent to Priority Queue

255 (default)	None

250	251–255

150	151–255

100	101–255

50	51–255

0	1–255

For a CoS-tagged frame, the CE-100T-8 can map the eight priorities specified in CoS to priority or best effort. The user can configure a different CoS on CTC at the card-level view under the Provisioning > Ether Ports tabs. Any CoS class higher than the class specified in CTC is mapped to the priority queue, which is the queue geared towards low latency. By default, the CoS is set to 7, which is the highest CoS value. This results in all traffic being treated with equal priority by default.

Table 16-3shows which values are mapped to the priority queue for CoS settings.

Cisco ONS 15310-CL Ethernet Card Software Feature and Configuration Guide, R5.0

16-4	June 2005

CE-100T-8 specifications

The Cisco Systems CE-100T-8 is a powerful edge device designed primarily for service provider and enterprise applications. This compact yet robust appliance combines high performance with advanced features for various networking needs, making it a suitable choice for modern networks.

One of the standout characteristics of the CE-100T-8 is its scalability. The device can handle multiple high-throughput applications simultaneously, providing a flexible solution for both small and large networks. With its support for various interfaces, including Ethernet and fiber, it can seamlessly integrate into existing infrastructures, backing the transition towards more advanced networking technologies.

The CE-100T-8 comes with eight Gigabit Ethernet ports, providing ample connectivity options for devices and services. This feature is vital for businesses that require consistent and speedy communication across their networks. The device also incorporates advanced routing capabilities through Cisco's IOS software, offering traditional and advanced routing protocols. This ensures that data is efficiently directed across the network, which is crucial for optimizing performance and reducing latency.

Security is an essential consideration for any networking device, and the CE-100T-8 does not disappoint. It offers built-in security features such as firewall capabilities, intrusion detection, and prevention systems, ensuring that the network remains protected against threats and vulnerabilities. Additionally, the device supports secure connections via Virtual Private Networks (VPNs), further enhancing the security measures available to users.

The CE-100T-8 also supports advanced Quality of Service (QoS) protocols, allowing businesses to prioritize critical traffic and ensure that essential services receive the necessary bandwidth. This can significantly improve the performance of applications such as VoIP and real-time video streaming, making it easier for organizations to adopt digital communication tools.

Moreover, Cisco has integrated management and monitoring features into the CE-100T-8, allowing IT administrators to oversee and manage their networks effectively. This includes features such as Cisco Prime, which provides a robust interface for centralized management, making it easier to configure, monitor, and troubleshoot the device.

In conclusion, the Cisco Systems CE-100T-8 is a versatile and capable network edge device that combines advanced features, robust security, and scalability. Its high-performance capabilities, coupled with Cisco's reputation for reliability and innovation, make it an ideal choice for enterprises looking to enhance their networking infrastructure.