15454-ML1000-2 Cisco ONS Ethernet Interface Card.

Architectural Overview and Role in the ONS 15454 Ecosystem

The ML1000-2 card is not a simple media converter; it is a sophisticated, wire-speed Gigabit Ethernet switch embedded within a single-slot ONS 15454 module. It operates by mapping Ethernet frames into the payload of SONET/SDH circuits (e.g., STS-Nc or VC-4-Nc), a process standardized by the Generic Framing Procedure (GFP), Virtual Concatenation (VCAT), and the Link Capacity Adjustment Scheme (LCAS). This allows for efficient, flexible bandwidth utilization, where Ethernet services can be provisioned in granular increments from a few Mbps up to the full line rate, independent of the rigid SONET/SDH hierarchy. The card occupies one slot in the ONS 15454 shelf and connects to the backplane's high-speed switching fabric, enabling it to communicate with other optical (e.g., OSM) and electrical cards within the node and across the network.

Key System Integration Features

Backplane Connectivity and Bandwidth

The ML1000-2 leverages the ONS 15454's 1.2 Gbps slot bandwidth for transport side (SONET/SDH) connections. Its two external Gigabit Ethernet ports provide the client-facing interfaces, while internally, it can be cross-connected to any other slot in the shelf via Software Configurable Optical Add/Drop Multiplexer (SCO) or Electrical Cross-Connect (EC) functionality.

Unified Management Paradigm

A principal advantage of the ML-Series category is its management through the same Cisco Transport Controller (CTC) software used for the entire ONS 15454 system. This provides a single-pane-of-glass view for both TDM and Ethernet services, simplifying operations, provisioning, and troubleshooting.

Deep Dive: Cisco 15454-ML1000-2 Hardware Specifications

The ML1000-2 is engineered for carrier-class reliability and performance. Its hardware design reflects the rigorous requirements of always-on telecommunications infrastructure.

Physical Interfaces and Port Configuration

The card features two fixed, industry-standard Small Form-factor Pluggable (SFP) slots for Gigabit Ethernet connectivity. This SFP-based design offers critical flexibility:

Interface Flexibility: Support for a wide array of Cisco-approved SFP optics, including 1000BASE-SX (multimode), 1000BASE-LX/LH (single-mode), 1000BASE-ZX (extended reach), and 1000BASE-T (copper, over Cat5e/Cat6).

Distance Adaptation: Network architects can choose optics matching the required reach, from intra-building links to distances over 70 km with ZX optics.

Hot-Swappable Components: SFPs can be replaced without powering down the card or affecting the other port, facilitating easy upgrades or repairs.

Performance and Switching Capacity

As a Layer 2 switch, the ML1000-2 delivers non-blocking, wire-speed performance on both ports simultaneously. It maintains full line rate forwarding regardless of frame size, packet type, or enabled network features. The card is equipped with a high-performance ASIC and sufficient memory to handle large forwarding tables and traffic bursts.

Key Performance Indicators

Forwarding Rate: Up to 2.68 million packets per second (pps) aggregate.
MAC Address Table Size: Supports up to 32,000 learned MAC addresses, essential for scaling Ethernet LAN services.
Jumbo Frames: Supports jumbo frames up to 9216 bytes, optimizing throughput for large data transfers common in storage and data center interconnect applications.

Advanced Software Features and Service Provisioning

The true power of the ML1000-2 card is unlocked through its comprehensive software feature set, which enables the creation of differentiated, revenue-generating Ethernet services.

Ethernet Service Types (E-Line, E-LAN, E-Tree)

The card supports MEF (Metro Ethernet Forum) compliant service definitions, allowing service providers to offer standardized wholesale or retail services.

E-Line (Point-to-Point Ethernet Virtual Connection)

Created using Ethernet over SONET/SDH circuits cross-connected between two ML-Series cards. This emulates a dedicated private line or a virtual private wire service (VPWS).

E-LAN (Multipoint-to-Multipoint Ethernet Virtual Connection)

Enabled by the card's full IEEE 802.1Q VLAN bridging and Spanning Tree Protocol (STP) capabilities. Multiple customer sites can be connected in a multipoint bridged LAN across the metro network.

E-Tree (Rooted Multipoint Ethernet Virtual Connection)

Supported through advanced VLAN and forwarding database management, allowing hub-and-spoke topologies ideal for broadband aggregation or franchise networks.

Quality of Service (QoS) and Traffic Management

To ensure service level agreements (SLAs) are met, the ML1000-2 implements robust, multilayer QoS.

Classification and Marking: Traffic can be classified based on ingress port, MAC address, IP precedence/DSCP, VLAN ID, or EtherType. It can be marked or remarked for consistent treatment across the network.
Policing and Shaping: Ingress policing enforces committed information rate (CIR) and peak information rate (PIR). Egress shaping smoothes traffic flows onto SONET/SDH circuits to prevent packet loss.
Scheduling: Strict priority queuing (PQ) and weighted fair queuing (WFQ) ensure critical, low-latency traffic (like voice or financial transactions) is prioritized.

Deployment Scenarios and Use Cases

The versatility of the ML1000-2 card makes it suitable for a broad spectrum of deployment models within metro and regional network architectures.

Metro Ethernet Access and Aggregation

In this primary use case, ML1000-2 cards deployed in edge ONS 15454 nodes aggregate customer-premises equipment (CPE) traffic (e.g., from a business router or switch). The Gigabit Ethernet ports connect to the customer hand-off, while the Ethernet traffic is groomed and mapped onto efficient SONET/SDH circuits for transport to a central hub or data center. This model is ideal for offering transparent LAN services to enterprise customers.

Cell Site Backhaul for 3G/4G (LTE) Networks

The ONS 15454 with ML-Series cards was a historical workhorse for mobile backhaul. The ML1000-2 could aggregate IP-based Radio Access Network (RAN) traffic from multiple cell sites. Its stringent QoS mechanisms ensured priority treatment for voice and real-time signaling, while SONET/SDH protection guaranteed the high availability required by mobile operators.

Data Center Interconnect (DCI)

For enterprises or service providers interconnecting geographically separate data centers, the ML1000-2 provides a high-speed, low-latency link. The ability to support jumbo frames and guarantee bandwidth via SONET/SDH circuits makes it suitable for synchronous replication, VM migration, and storage area network (SAN) extension applications, especially in networks with existing ONS 15454 infrastructure.

Converged Network Core for Government and Utilities

Municipalities, transportation authorities, and utility companies often operate private optical networks. The ONS 15454 with ML1000-2 cards allows them to converge legacy SCADA/telemetry systems (transported via TDM) and modern IP-based applications (video surveillance, IP telephony, office data) onto a single, manageable, and highly resilient infrastructure.

Compatibility and Interoperability

The ML1000-2 card is designed for seamless integration within the broader Cisco ONS ecosystem and multi-vendor environments.

Platform Compatibility

The card is compatible with specific ONS 15454 shelf assemblies and requires a minimum software release of Cisco Transport Controller (CTC) and ONS system software. It is crucial to consult the official Cisco compatibility matrix for details on supported backplane types (e.g., ONS 15454 SCSI, ONS 15454 M6) and required firmware.

Interoperability with Other Network Elements

At the Ethernet layer, it interoperates seamlessly with standard IEEE 802.3 and 802.1Q-compliant switches and routers. At the transport layer, the SONET/SDH circuits it uses can interconnect with other ONS nodes or any third-party SDH/SONET equipment adhering to ITU-T and ANSI standards, ensuring broad network compatibility.

Migration to Next-Generation Platforms

While the ONS 15454 and ML-Series cards remain deployed in many networks, Cisco's innovation has progressed to platforms like the Cisco Network Convergence System (NCS) and Cisco Crosswork Network Controller for packet-optical convergence and SDN-based control. Understanding the capabilities of the ML1000-2 provides a foundational knowledge of Ethernet transport evolution, informing migration strategies to newer technologies like MPLS-TP and Segment Routing.