Chapter 12 Configuring Quality of Service on the ML-Series Card

Understanding QoS

Understanding QoS

The ML-Series card multiplexes multiple IP/Ethernet services onto the SONET circuit and dynamically allocates transmission bandwidth to data services based on data service requirements. This allows the network to operate at a significantly higher level of utilization. To support service-level agreements (SLAs), this dynamic allocation must accommodate the service elements of bandwidth, including loss and delay. The characteristics of these service elements make up QoS.

The QoS mechanism has three basic steps. It classifies types of traffic, specifies what action to take against a type of traffic, and specifies where the action should take place.

Priority Mechanism in IP and Ethernet

For any QoS service to be applied to data, there must be a way to mark or identify an IP packet or an Ethernet frame. When identified, a specific priority can be assigned to each individual IP packet or Ethernet frame. The IP Precedence or the IP Differentiated Services Code Point (DSCP) field prioritizes the IP packets, and the Ethernet class of service (IEEE 802.1p defined class of service [CoS]) is used for the Ethernet frames. IP precedence and Ethernet CoS are further described in the following sections.

IP Precedence and Differentiated Services Code Point

IP precedence uses the three precedence bits in the IPv4 header’s ToS (type of service) field to specify class of service for each IP packet (RFC 1122). The most significant three bits of the IPv4 ToS field provide up to eight distinct classes, of which six are used for classifying services and the remaining two are reserved. On the edge of the network, the IP precedence is assigned by the client device or the ML Series, so that each subsequent network element can provide services based on the determined policy or the SLA.

IP DSCP uses the six bits in the IPv4 header to specify class of service for each IP packet (RFC 2474). Figure 12-1illustrates IP precedence and DSCP. The DSCP field classifies packets into any of the

64 possible classes. On the network edge, the IP DSCP is assigned by the client device or the ML Series, so that each subsequent network element can provide services based on the determined policy or the SLA.

Cisco ONS 15310-CL, ONS 15310-MA, and ONS 15310-MA SDH Ethernet Card Software Feature and Configuration Guide, R9.1 and R9.2

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ONS 15310-CL, ONS 15310-MA, Cisco ONS 15310-MA specifications

Cisco Systems has long been a leader in networking and telecommunications technology, and among its impressive lineup of products, the Cisco ONS 15310 series stands out as an essential solution for optical networking. This series includes models such as the ONS 15310-MA, ONS 15310-CL, and ONS 15310-CA, each designed to meet the diverse needs of service providers and enterprises seeking to enhance their optical transport networks.

The Cisco ONS 15310-MA is an advanced multi-service platform designed for metropolitan area networks. It facilitates the seamless transport of data, voice, and video over optical networks. One of its main features is its ability to support a variety of interfaces, including Ethernet, SONET/SDH, and Wavelength Division Multiplexing (WDM), allowing users to integrate multiple services into a single platform. Additionally, the ONS 15310-MA supports advanced traffic management and Quality of Service (QoS) features to prioritize critical applications and ensure consistent performance.

The ONS 15310-CL variant is tailored for more specific applications, providing enhanced capabilities aimed at delivering carrier-grade services. It features a robust architecture that accommodates high-capacity traffic without compromising reliability. This model emphasizes low power consumption and a compact design, making it suitable for deployment in space-constrained environments. The ONS 15310-CL also supports a wide range of optical interfaces, making it highly flexible for various network configurations.

In terms of technologies, the Cisco ONS 15310 series leverages Optical Transport Network (OTN) capabilities, providing high efficiency and greater bandwidth utilization. OTN technology enables efficient error correction and adds resilience to the network through its built-in protection mechanisms. Furthermore, the series supports seamless integration with existing IP/MPLS networks, creating a cohesive infrastructure as organizations evolve their networking requirements.

One of the defining characteristics of the ONS 15310 series is its focus on scalability. Network operators can start with a modest deployment and gradually expand capacity as demand grows. This adaptability is complemented by Cisco's comprehensive management and monitoring tools, providing operators with real-time insights into network performance and facilitating proactive management.

In conclusion, the Cisco ONS 15310-MA and ONS 15310-CL models represent sophisticated solutions for modern optical networks. With their versatile features, advanced technologies, and robust design, they empower service providers and enterprises to build resilient, high-capacity networks that meet the demands of today’s data-driven world.
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