{
  "slug": "fcip",
  "term": "Fibre Channel over TCP/IP",
  "aliases": [
    "FCIP"
  ],
  "definition": "Fibre Channel over TCP/IP (FCIP) transports encapsulated FC frames over TCP connections to join separated portions of one Fibre Channel fabric.",
  "note": "An FCIP link may use several TCP connections; ordering is per connection, not an unconditional guarantee across the link. [rfc3821] The common encapsulation retains the FC CRC and represents frame delimiters separately; FC frame-lifetime limits still matter across the IP path. [rfc3643]\n\nIP protocol number 133 belongs to a pre-standard format, not standardized FCIP, which uses TCP. [rfc6172] iFCP is a different gateway protocol: its session binds an N_PORT pair to one TCP connection. [rfc4172] Its address-translation mode was deprecated; address-transparent mode was not. [rfc6172]\n\nA transport acknowledgement is not evidence of storage-command completion or durable data. This is a protocol-layer inference, not a power-failure measurement. [rfc3821]\n\nFC credits and TCP windows operate independently; coordination belongs to the implementation. FC Primitive Signals, Primitive Sequences and Class 1 frames are not tunneled. TCP keepalive alone does not guarantee prompt failure detection; the FC side should provide detection, and discovered TCP loss must be reported to it. [rfc3821]\n\nWhen no synchronized timestamp is available, RFC 3821 requires a zero timestamp; that does not mean the frame spent zero time in transit. [rfc3821] Transit-time calculation requires a valid timestamp and aligned, synchronized time bases. [rfc3643]",
  "status": "unknown",
  "advantages": [
    {
      "text": "Connects separated FC fabric portions through an IP network.",
      "citationIds": [
        "rfc3821"
      ]
    }
  ],
  "limitations": [
    {
      "text": "Round-trip delay, TCP windows and buffering constrain the usable path, beyond nominal bandwidth.",
      "citationIds": [
        "rfc3821"
      ]
    }
  ],
  "related": [
    "fibre-channel",
    "fc-frame",
    "san",
    "iscsi"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "citations": [
    {
      "id": "rfc3821",
      "title": "RFC 3821 (July 2004): FCIP, sections 4, 5.2, 5.6, 6, 8.3.2, 8.4, 8.5 and 10.1",
      "url": "https://www.rfc-editor.org/rfc/rfc3821.html",
      "accessed": "2026-11-02"
    },
    {
      "id": "rfc3643",
      "title": "RFC 3643 (December 2003): FC frame encapsulation, sections 2, 4 and 5",
      "url": "https://www.rfc-editor.org/rfc/rfc3643.html",
      "accessed": "2026-11-02"
    },
    {
      "id": "rfc4172",
      "title": "RFC 4172 (September 2005): iFCP session model, section 5.2.1",
      "url": "https://www.rfc-editor.org/rfc/rfc4172.html",
      "accessed": "2026-11-02"
    },
    {
      "id": "rfc6172",
      "title": "RFC 6172 (March 2011): iFCP mode deprecation and FCIP protocol number, sections 3.2 and 4",
      "url": "https://www.rfc-editor.org/rfc/rfc6172.html",
      "accessed": "2026-11-02"
    },
    {
      "id": "rfc7146",
      "title": "RFC 7146 (April 2014): IPsec requirements update for storage protocols",
      "url": "https://www.rfc-editor.org/rfc/rfc7146.html",
      "accessed": "2026-11-02"
    }
  ],
  "updated": "2026-11-02",
  "provenance": [
    "Foundational architecture review, not a WAN benchmark; status unknown means current commercial availability was not assessed.",
    "RFC 7146 updates the older security requirements. This record is not current cryptographic configuration guidance; TCP alone does not establish encryption. [rfc7146]"
  ]
}