Mahi Networks
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Mahi Networks was a Petaluma, California-based venture-funded network equipment startup company. It was founded in 1999 and focused on developing carrier-class multiservice switching platforms for metro and regional networks.
Mahi's flagship product, the Mi7 Metro Core Aggregation System, was a 320 Gbit/s multi-service switching system supporting SONET/SDH TDM switching, MPLS/Ethernet switching, and IP routing. Its multi-service capability was achieved using a switching fabric based on the Tiny Tera architecture.[1][2]
Switching Fabric
At the core of Mahi’s product line was the Mi7 Metro Core Aggregation System (MCAS) — a converged platform combining SONET/SDH add/drop multiplexing, Layer 2 Ethernet switching, and a GMPLS-based control plane. The system was designed to simplify metro and regional central office architectures by replacing stacked MSPPs, DSX panels, and manual cross-connects with software-configurable, high-density optical and electrical interconnects.
The Mi7 system integrated multiple subsystems, including:
- Optical Node Interconnection (ONX): Eliminated coax and DS3 cabling, enabling software-controlled cross-connects and reducing points of failure.
- SONET Ring Aggregation (SRA): Consolidated SONET/SDH ADM functionality to reduce space, power, and operational overhead.
- Metro Ethernet Transport (MET): Enabled carrier-class Ethernet services by integrating Layer 1 transport with Layer 2 statistical multiplexing and VLAN processing.
- Automated Transport Network (ATN): Used a GMPLS mesh architecture for automated A-to-Z provisioning across a dynamic, multi-vendor optical topology.
The system supported interface options ranging from DS3 to OC-192 and Gigabit Ethernet, with scalability features like tributary expansion shelves and pay-as-you-grow pricing. Mahi positioned the Mi7 as an enabler for converged service delivery—supporting legacy TDM, IP VPNs, and video over packet—with lower capital and operational costs.[3]
The Mi7 system’s switching fabric was based on the Tiny Tera architecture, a 320 Gbit/s input-queued packet switch developed at Stanford University.[4] The Tiny Tera design used a sliced crossbar architecture with centralized scheduling and high-speed serial links, allowing extremely high throughput using commercially available CMOS technology.
Mahi Networks adapted this architecture to support a combination of TDM (SONET/SDH) and packet (Ethernet/MPLS/IP) services in metro and regional networks. Key features included:
- Input-queued architecture with virtual output queuing to eliminate head-of-line blocking
- A centralized scheduler implementing fast arbitration algorithms such as iSLIP for near-100% throughput
- Use of high-speed chip-to-chip serial links to simplify the switch's physical interconnect and reduce power and board complexity
- Support for multicast scheduling and fanout-splitting, allowing efficient packet duplication across multiple destinations
- A modular, scalable fabric composed of crossbar slices and port processors, enabling pay-as-you-grow deployment
This approach enabled Mahi to build a cost-effective, high-performance switching core suitable for converged transport across telecom central offices.