Chapter 17 CE-Series Ethernet Cards

CE-MR-6 Ethernet Card

To prevent over-subscription, buffer memory is available for each port. When the buffer memory on the Ethernet port nears capacity, the CE-MR-6 card uses IEEE 802.3x flow control to transmit a pause frame to the attached Ethernet device. Flow control and auto negotiation frames are local to the Ethernet (10 Mbps), Fast Ethernet (100 Mbps), Gigabit Ethernet (1000 Mbps) interfaces and attached Ethernet devices. These frames do not continue through the POS ports.

The CE-MR-6 card has asymmetric flow control and proposes asymmetric flow control when auto negotiating flow control with attached Ethernet devices.

The pause frame instructs the source to stop sending packets for a specific period of time. The sending station waits the requested amount of time before sending more data. Figure 17-7illustrates pause frames being sent and received by CE-MR-6 cards and attached switches.

Figure 17-7

Flow Control

ONS Node

STS-N

Ethernet

 

 

SONET

Pause Frames

 

ONS Node

Ethernet

115779

Pause Frames

This flow-control mechanism matches the sending and receiving device throughput the bandwidth of the STS circuit. For example, a router might transmit to the Ethernet port on the CE-MR-6 card. This particular data rate might occasionally exceed 51.84 Mbps, but the SONET circuit assigned to the CE-MR-6 port might be only STS-1 (51.84 Mbps). Under this condition, the CE-MR-6 sends out a pause frame and requests that the router delay its transmission for a certain period of time. With flow control and a substantial per-port buffering capability, a private line service provisioned at less than full line rate capacity (STS-1) is efficient because frame loss is controlled to a large extent.

Ethernet Link Integrity Support

The CE-MR-6 supports end-to-end Ethernet link integrity (Figure 17-8). This capability is integral to providing an Ethernet private line service and correct operation of Layer 2 and Layer 3 protocols on the attached Ethernet devices. Link integrity is implemented so that the Ethernet over SONET connection behaves more like an Ethernet cable from the viewpoint of the attached Ethernet devices.

End-to-end Ethernet link integrity means that if any part of the end-to-end path fails, the entire path fails. It disables the Ethernet port transmitter on the CE-MR-6 card when the remote Ethernet port does not have a receive signal or when the SONET near end or far-end failure is detected. The failure of the entire path is ensured by turning off the transmit pair at each end of the path. If any part of the end-to-end path fails, the CE-MR-6 card soaks the defect for a fixed duration of 200 ms. The attached Ethernet devices recognize the disabled transmit pair as a loss of carrier and consequently an inactive link or link failure. The transport fail alarm is raised when the port transmitter is disabled. Link integrity supports a double fault, that is, when both the Ethernet ports do not receive a signal.

Note Only bidirectional link integrity is supported on the CE-MR-6 card.

 

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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Cisco Systems ONS 15310-CL, Cisco ONS 15310-MA manual 17-14, Flow Control
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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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