|TCP Offload Engine (TOE) is a technology employed on Chelsio’s Terminator series (T4 and T5) adapters to offload the processing of TCP/IP stack onto the Network Interface Card (NIC) and remove it from the host machine. This has several advantages: first, it frees up the CPU for other useful work; second, it eliminates some of the data transfers required since the card acts on the data locally. All the host processor needs to do is open the connection and the offload technology on the card will take it from there.
Having considered various typical arguments against TOE, and argued why Chelsio’s approach avoids the pitfalls at the root of these arguments, it is important to discuss the actual performance impact of TCP/IP offloading. Chelsio’s family of Unified Wire Adapters is the first and currently unique 10 Gbps / 10GbE and 40Gbps / 40GbE offload engine.
The ability of TOE to perform full transport layer functionality is essential to obtaining tangible benefits. The important aspect of the this layer is it being the process-to-process layer, i.e. the data passed to the offload engine comes straight from the application process, and the data delivered by the engine is ready to be passed to the application process. In contrast, lower layers only provide unreliable delivery functionality, which limits the usability of the data at these levels. This opens the way for very powerful extensions to pure protocol offload based on TOE, including:
The Terminator series of adapters can offload TCP/IP processing per connection, per-server, per-interface, and globally and simultaneously tunnel traffic from non-offloaded connections to the host processor for the native TCP/IP stack to process. The adapters provide a flexible zero copy capability for regular TCP connections, requiring no changes to the sender, to deliver line rate performance at minimal CPU utilization.
The following platforms are supported:-