emNet

The high-performance Dual IPv4/IPv6 IP Stack for Embedded Systems

Key features

Use Cases

emNet is a streamlined, high-performance TCP/IP stack for embedded systems. It is particularly suited to resource-constrained systems with limited RAM or flash memory. Typical use cases focus on network-enabled embedded devices for which reliability, determinism, and a small memory footprint are important.

Embedded Web Interfaces

IoT Devices and Edge Nodes

How emNet Works

emNet manages network communication by abstracting hardware through a network-interface driver. It uses standard Internet communication protocols and is optimized for real-time behavior and low memory consumption. It sits between a user's application, the real-time operating system in use, and the respective Ethernet or Wi-Fi hardware driver. Applications interact with emNet via a BSD-like socket API.

To ensure reliable communication even under adverse network conditions, emNet is designed to handle high traffic loads efficiently and protect system resources. A single task is employed to manage incoming data packets, and built-in mechanisms such as UDP flood protection prevent excessive load, freeing up CPU time for other tasks.

Layered Architecture

Supported Protocols

Built-In Services

emNet includes a set of ready-to-use network services for common infrastructure and device discovery tasks:

Available Add-Ons

Add-On	Description
emFTP Server	File Transfer Protocol (Server) - You need emFile or Simulate its API with your own file system
emFTP Client	File Transfer Protocol (Client) - You need emFile or Simulate its API with your own file system
emWeb	Web Server
emNet PPP/PPPoE	Point-to-Point Protocol
emNet SNMP Agent	Simple Network Management Protocol (SNMPv1/SNMPv2c)
emNet SNMP Agent SNMPv3 USM	SNMPv3 User-based Security Model Extension Requires emNet SNMP Agent
emNet UPnP	Universal Plug and Play Module, requires emWeb
emNet SMTP Client	Simple Mail Transfer Protocol (Client)
emNet Tail Tagging	Virtual extension of any single-port CPU to manage interfaces at low cost
emMQTT Client	Message Queuing Telemetry Transport (MQTT) protocol (Client)
emNet PTP OC Slave	PTP (IEEE1588-2008) Ordinary Clock Client
emNet CoAP Server/Client	Constrained Application Protocol (Server/Client)
emNet PTP OC Simple Master	PTP (IEEE1588-2008) Ordinary Clock Master with simple and limited capabilities
emNet WebSocket	WebSocket Protocol

Drivers

By design, emNet supports both internal and external Ethernet MACs (Media Access Controls), meaning any standard microcontroller can connect to Ethernet. With emNet, even small, ultra-low-power microcontrollers with minimal flash memory and no on-chip MAC can be used.

With its optional drivers, emNet's list of supported devices is extensive. The few existing hardware dependencies are handled in a single place, and hardware switches are effortless. If a controller is not on the list, support is likely possible via currently available drivers

Ethernet-APL

emNet supports Ethernet-APL, the standardized APL for two-wire data transmission. This means users get consistent and fast IP communication over long cable lengths. Ethernet-APL is specifically designed for applications in highly explosive environments/hazardous areas.

PHY Compatibility

emNet also supports virtually any Ethernet Physical Layer (PHY) transceiver through a flexible PHY driver layer. Included with emNet is a generic PHY driver that is compatible with almost all single-port PHYs on the market that use the IEEE 802.3u standard. Support for other PHY-like devices such as Ethernet switches is also possible.