Effnet EthHC™

Ethernet is the dominant computer networking technology for local area networks. It has replaced other competing wired LAN technologies. There are many benefits in connecting two separate LANs by simply extending the Ethernet link between the two networks instead of routing the packets over another network. For example, a UHF/VHF link used to connect two LANs. But in this case, Ethernet header itself becomes a significant overhead when payload is small.

Effnet EthHC™ can efficiently compress the Ethernet header. It is best used in the two end-points of the link connecting two LANs carrying Ethernet frames. It is designed to work in perfect symbiosis with the Effnet ROHC™ product portfolio. As shown in figure 1, this combination can save a significant amount of bandwidth by compressing Ethernet headers along with compression of IP/UDP/RTP, IP/UDP, IP/TCP and IP/ESP headers.


Above shows an example of traffic compressed using Effnet EthHC™ and Effnet ROHC™.


Figure 1: Example of bandwidth savings using Effnet EthHC™ together with Effnet ROHC™ for streaming traffic (VoIP).

Table 1: Examples of packet size savings using Effnet ROHC and Effnet EthHC for TCP acknowledgment and data traffic, including link layer header.

Traffic type Avg. pkt size w/o. ROHC* (bytes) Pkt size w. ROHC (bytes) Pkt size w. ROHC and EthHC (bytes) Savings w. ROHC (%) Savings w. ROHC and EthHC (%)
TCP ACK 58 28 11 52 81
TCP Data 668 638 621 4 7

UDP Data

483 478 461 1 5

*Average packet size from packet traces at the MAWI project.

General features

  • 100% transparent compression
  • Lightweight implementation suitable for low-end devices
  • Highly portable ANSI C code with no operating system dependencies
  • Platform, endianness and byte-order independent
  • Highly configurable with compile and run-time options
  • Highly modular with external memory management
  • Multi-threading support

Effnet Classifier and Context Manager (EFFRCCM™)

The classification and context management is an essential component of header compression function.

  • Handles typical classification requirements for Ethernet header compression flows.
  • Performs exact matching on all pertinent header fields, including MAC destination and MAC source.
  • Provides sufficient information for CID management.
  • Provides context associated with a packet via context management.
  • When used together with Effnet ROHC™, the classification results from Effnet ROHC™can be re-used in Effnet EthHC™.


Effnet provides support and maintenance services covering problem reporting, bug fixes, updates, training, consulting and integration. A sample application code together with detailed documentation covering well defined and easy to use API is provided to speed up the process of integration.

White Papers

Learn more about IP header compression from our white papers.

An introduction to IP header compression
An introduction to IP header compression
The concept of robust header compression, ROHC
The concept of ROHC