Overview
ISO/IEC 14165-331:2007 - Information technology - Fibre Channel - Part 331: Virtual Interface (FC‑VI) - specifies an upper‑layer protocol that runs over Fibre Channel to enable efficient peer‑to‑peer and client‑server messaging. The standard maps the Virtual Interface (VI) Architecture onto Fibre Channel’s high‑speed serial transport (optical or electrical), supporting topologies such as point‑to‑point, switched fabric, and arbitrated loop. It is intended for vendors and implementers who need to build FC‑VI compliant devices and software for storage and networking environments.
Key topics and technical requirements
- FC‑VI protocol overview: Defines roles of FC‑VI information units (IUs) and the message transfer model for low‑latency communication.
- IU types and formats: Standardized IUs include SEND, SEND_RESP, WRITE_RQST/RESP, READ_RQST/RESP, CONNECT_RQST/RESP, and DISCONNECT IUs with detailed device_header fields and parameters.
- RDMA and message semantics: Support for RDMA write/read operations and explicit send/receive message exchanges to enable zero‑copy data movement and reduced CPU overhead.
- Connection setup and teardown: Procedures for client‑server and peer‑to‑peer connection establishment, concurrent connection handling, disconnect operations, and related control flags.
- Addressing and naming: FC‑VI addressing formats, name‑service queries, FARP ELS handling and validation of host address ↔ N_Port mappings for fabric, loop, and point‑to‑point topologies.
- Error detection and recovery: Endpoint state machine, transfer error detection/recovery rules, connection retry behavior, and ULP timeout considerations.
- Frame/header usage: Mapping to Fibre Channel frame fields (FC‑FS header usage) and reuse rules for exchange/sequence IDs and frame synonym detection.
Applications and who uses this standard
- Storage network vendors building HBAs (Host Bus Adapters), adapters, and firmware that implement Fibre Channel transport with VI semantics.
- Server/NIC designers implementing FC‑VI offload for high‑performance block and file storage (SCSI, IPI) or ULPs like IP.
- Data center architects and storage integrators who must ensure interoperability and low‑latency data paths in SANs.
- Software developers and driver engineers writing OS kernel drivers or middleware that expose VI‑style APIs over Fibre Channel.
- Use cases: high‑performance SANs, clustered storage, low‑latency RDMA over Fibre Channel, and back‑end data replication.
Related standards
- The FC‑VI part is one element of the broader Fibre Channel standards family and references the VI Architecture and other Fibre Channel normative documents. It also interoperates with upper‑level protocols such as SCSI, IPI, IP, and IEEE 802.2 as noted in the scope. For implementation, consult the other normatively referenced Fibre Channel and VI architecture standards.