Terminator 5 Adapter Range

High Performance, Quad Port 1/10/25GbE Unified Wire Adapter

Enables TCP, UDP, iSCSI, iWARP, FCoE, TLS/SSL, DTLS, IPsec, SMB 3.X crypto, and SDN Offload over Single Unified Wire with SR-IOV, EVB/VNTag and DCB


Chelsio’s T6425-CR is a quad port, ultra-low latency 1/10/25Gb Ethernet Unified Wire Adapter, with a PCI Express 3.0 x8 host bus interface, optimized for storage, cloud computing, HPC, virtualization and other datacenter networking applications.

The host machine should support PCIE bifurcation to enable all the 4 Ports of T6425-CR. Otherwise, only 2 ports will be enabled. It runs all the host software of its predecessor, T5, as-is, thus enabling leveraging of all the prior software investment. It offers all the features of T5, and in addition adds support for integrated offload of IPsec, TLS/SSL, DTLS and SMB 3.X crypto.

T6425-CR provides sub micro-second end-to-end latency, while offloading the host CPU from a variety of typical storage, networking, and cloud related protocols. This will enable savings in host CPU acquisition costs, power and operational costs, and dramatically increases system performance.

A large portion of offloads enabled by T6425-CR are based on standard TCP, IP, UDP protocols (such as iSCSI and iWARP), and thus can operate with a software peer, or be replaced with a software solution at lower performance, thus providing the requisite reliability for enterprise customers, and allowing incremental installs in the datacenter. It will work with any legacy switch infrastructure and does not rely on new features such as DCB, PFC, ETS, etc.

T6425-CR supports IEEE standards-based link aggregation/failover features, as well as inter-adapter failover techniques that make it ideal for critical network applications requiring redundancy and high-availability capabilities. It also includes an integrated Traffic Manager and a built-in eSwitch for robust network traffic flow control, traffic classifier, load balancer, Firewall capabilities at the port level.

FCoE and iSCSI support in T6425-CR benefit from high reliability features that include memory ECC, data path CRC and T10-DIX offload, in addition to the checksums and CRC available at different protocols layers. High performance iSCSI and FCoE provide a drop-in replacement upgrade from legacy SANs to converged networks.

The Unified Wire Solution

T6425-CR enables a unified wire for LAN, SAN and cluster applications, built upon a high bandwidth and low latency architecture along with a complete set of storage and cluster protocols operating over Ethernet (iSCSI, NVMe-oF, FCoE and iWARP). A unified wire means having the ability to utilize all offload or non-offload protocols at the same time, over the same link, using the exact same firmware, host software, and adapter. Thus, a given system using T6425-CR can be easily targeted at different vertical markets and a variety of useful functions enabled (i.e. dial the bandwidth to a given application and assign access control, while offloading only part of the traffic). The Ethernet-only networking thus reduces the infrastructure costs in network adapters, cables, switches, rack space, power, equipment spares, management tools, planning, networking staff and installation.

Sixth-Generation Protocol Offload Engine

T6 is Chelsio’s sixth-generation TCP offload (TOE) design, fifth-generation iSCSI design, and fourth-generation iWARP (RDMA) implementation. With support for the 8 Gbps PCIe Gen3 data rate, it provides 128Gbps of raw bandwidth. Also provides support for PCIe SR-IOV virtualization with embedded virtual switch.

Complete and Flexible TCP Offload

The T6425-CR transport engine executes programmable firmware and is configurable with hundreds of registers for protocol parameters, RFC compliance and offload control. It can offload protocol processing per connection, per-server, per-interface, while simultaneously providing complete stateless offload for non-offloaded connections (processed by operating systems stack running on host CPU). It also provides a flexible direct data placement capability for regular TCP sockets, with all the benefits of zero-copy and kernel bypass without rewriting the applications.

High Performance Security Offload

T6425-CR introduces ground breaking TLS/SSL performance with inline cryptographic functions leveraging Chelsio’s proprietary TCP/IP offload engine. Chelsio’s full offload TLS/SSL is uniquely capable of 100Gb line rate performance. In addition, it can be used with inline mode for DTLS and in a traditional co-processor lookaside mode to accelerate IPsec, TLS/SSL with AES, SHA1 and SHA2 processing and SMB 3.X crypto.

Packet Switching and Routing

T6425-CR integrates a high performance packet switch, which allows switching traffic from any of the input ports to any of the output ports (wire-to-wire) and from any of the output ports to any of the input ports (host-to-host).

Robust, Proven Solution

Subjected to thousands of hours of compatibility testing, over a decade of stress testing by several OEM test suites and production deployment in servers, storage systems and cluster computing, Chelsio’s robust, stable protocol offload technology delivers proven performance in a wide range of environments.

Software Drivers

Chelsio offers a full suite of protocol software drivers with the T6425-CR adapters. See Support Page for the latest information. The software suite supports operation in both stateful and stateless offload modes for all major operating systems.

Ordering Information

Model: T6425-CR
Physical Interface: 25GBASE-SR/LR*
Connector: SFP28
Media: MMF or SMF or Twinax


SM10G-SR/LR: 10G short/long reach SFP optical module
SM25G-SR/LR: 25G short/long reach SFP28 optical module
TAPCABLE-1M/3M/5M: Twinax/DAC passive cable for 10Gb, 1M/3M/5M
TAPCABLE28-1M/2M/3M: Twinax/DAC passive cable for 25Gb, 1M/2M/3M
SRCABLE3M/LRCABLE3M: Short/Long reach fiber optic cable for 10Gb and 25Gb, 3M

* SFP28 optics sold separately. Only Chelsio-supplied modules may be used.