Small Form Factor Notes

Objective

本篇是記錄關於 SFF (Small Form Factor) 的相關規範，尤其是裡面的 EEPROM 資訊之驗證

SFF Spec list

SNIA, Storage Networking Industry Association 是一個提供全球包含儲存、網路工業標準的國際組織，成員大多由各大網通或儲存廠商所組成。此組織針對 SFF (Small Form Factor) 定義了目前常見的規範如下:

Spec	Full name
SFF-8024	SFF Committee Cross Reference to Industry Products
SFF-8436	Quad Small Form-factor pluggable SFF-8436 (QSFP+)
SFF-8472	Diagnostic Monitoring Interface for Optical Transceivers (SFP+)
SFF-8636	Management Interface for Cabled Environments
SFF-8665	QSFP+ 28 Gb/s 4X Pluggable Transceiver Solution (QSFP28)

More information: SNIA Public Documents

SFF Standards Compliance

根據 SFF-8024 SFF Committee Cross Reference to Industry Products TABLE 3-1 PLUGGABLE CONNECTORS 文件指出，針對不同類型的 SFF 有各種適當的規範

以下是針對 DAC (Direct Attach Copper) 相關整理:

• 10Gb/s SFP+ DAC

  • IEEE 802.3ae (10GbE)
  • Electrical: SFF-8431, SFF-8083
  • Mechanical: SFF-8432
  • EEPROM: SFF-8472

• 25Gb/s SFP28 DAC

  • EEPROM: SFF-8402

• 40Gb/s QSFP+ DAC

  • IEEE 802.3ba (40GbE or 100GbE)
  • Electrical: IBTA V2 Revision 1.2.1 and 1.3
  • EEPROM: SFF-8436

• 100Gb/s QSFP28 DAC

  • IEEE 802.3bj (100GbE)
  • EEPROM: SFF-8665

Hands-on

Environment:

• Environment
  • Cumulus Networks Cumulus Linux 3.2.1
• Edgecore ET6402-40GDAC-3M
  • DAC (Direct Attach Copper)
  • QSFP+
  • 3M

EEPROM

• Output Using ethtool -m

  [email protected]:~# ethtool -m swp49 |less
          Identifier                                : 0x0d (QSFP+)
          Extended identifier                       : 0x00 (1.5W max. Power consumption, No CDR in TX, No CDR in RX)
          Connector                                 : 0x23 (No separable connector)
          Transceiver codes                         : 0x08 0x00 0x00 0x00 0x00 0x00 0x00 0x00
          Transceiver type                          : 40G Ethernet: 40G Base-CR4
          Encoding                                  : 0x05 (64B/66B)
          BR, Nominal                               : 10300Mbps
          Rate identifier                           : 0x00
          Length (SMF,km)                           : 0km
          Length (OM3 50um)                         : 0m
          Length (OM2 50um)                         : 0m
          Length (OM1 62.5um)                       : 0m
          Length (Copper or Active cable)           : 3m
          Transmitter technology                    : 0xa0 (Copper cable unequalized)
          Attenuation at 2.5GHz                     : 3db
          Attenuation at 5.0GHz                     : 4db
          Vendor name                               : EDGE-CORE
          Vendor OUI                                : a8:b0:ae
          Vendor PN                                 : ET6402-40GDAC-3M
          Vendor rev                                : 0
          Vendor SN                                 : ***
          Laser bias current (Channel 1)            : 33.410 mA
          Laser bias current (Channel 2)            : 26.222 mA
          Laser bias current (Channel 3)            : 23.138 mA
          Laser bias current (Channel 4)            : 26.212 mA
          Receiver signal OMA(Channel 1)            : 1.7229 mW / 2.36 dBm
          Receiver signal OMA(Channel 2)            : 2.0561 mW / 3.13 dBm
          Receiver signal OMA(Channel 3)            : 1.6705 mW / 2.23 dBm
          Receiver signal OMA(Channel 4)            : 2.0547 mW / 3.13 dBm
          Module temperature                        : 0.00 degrees C / 32.00 degrees F
          Module voltage                            : 0.0000 V
          Alarm/warning flags implemented           : No

Details

因為這條線是 40G QSFP+，故 EEPROM 對照的規範應該要看 SFF-8436 的 7.6 QSFP+ Memory Map，而以上的資訊是遵照 7.6.2 Upper Memory Map Page 00h 的 Table 29 — Serial ID: Data Fields (Page 00) 裡的格式呈現

• 7.6.2.1 Identifier (Address 128)

  Identifier                                : 0x0d (QSFP+)

  • The identifier value specifies the physical device described by the serial information. The QSFP+ Module shall use the identifier 0Dh.

• 7.6.2.2 Extended Identifier (Address 129)

  Extended identifier                       : 0x00 (1.5W max. Power consumption, No CDR in TX, No CDR in RX)

  • The extended identifier provides additional information about the basic Module types such as whether the Module contains a CDR function and identifies the power consumption class it belongs to.

• 7.6.2.3 Connector (Address 130)

  Connector                                 : 0x23 (No separable connector)

  • The Connector value indicates the external connector provided on the interface. This value shall be included in the serial data. Note that 01h – 0Bh are not QSFP+ compatible, and are included for compatibility with other standards.

• 7.6.2.4 Specification compliance (Address 131-138)

  Transceiver codes                         : 0x08 0x00 0x00 0x00 0x00 0x00 0x00 0x00
  Transceiver type                          : 40G Ethernet: 40G Base-CR4

  • The following bit significant indicators define the electronic or optical interfaces that are supported by the QSFP+ Module. For Fibre Channel QSFP+s, the Fibre Channel speed, transmission media, transmitter technology, and distance capability shall all be indicated.
  • 0x08 0x00 0x00 0x00 0x00 0x00 0x00 0x00 == Address 131 (10/40G Ethernet Compliance Code), Bit 3 == 40G Base-CR4

• 7.6.2.5 Encoding (Address 139)

  Encoding                                  : 0x05 (64B/66B)

  • The encoding value indicates the serial encoding mechanism that is the nominal design target of the particular QSFP+ Module. The value shall be contained in the serial data.

• 7.6.2.13 Device Tech (Address 147)

  Transmitter technology                    : 0xa0 (Copper cable unequalized)

  • The top 4 bits of the Device Tech byte describe the device technology used. The lower four bits (bits 7-4) of the Device Tech byte are used to describe the transmitter technology.

• 7.6.2.{14, 16, 17, 18, 24} Vendor Name/OUI/PN/Rev/SN

  Vendor name                               : EDGE-CORE
  Vendor OUI                                : a8:b0:ae
  Vendor PN                                 : ET6402-40GDAC-3M
  Vendor rev                                : 0
  Vendor SN                                 : ***

• 7.6.2.26 Diagnostic Monitoring Type (Address 220)

  Laser bias current (Channel 1)            : 33.410 mA
  Laser bias current (Channel 2)            : 26.222 mA
  Laser bias current (Channel 3)            : 23.138 mA
  Laser bias current (Channel 4)            : 26.212 mA
  Receiver signal OMA(Channel 1)            : 1.7229 mW / 2.36 dBm
  Receiver signal OMA(Channel 2)            : 2.0561 mW / 3.13 dBm
  Receiver signal OMA(Channel 3)            : 1.6705 mW / 2.23 dBm
  Receiver signal OMA(Channel 4)            : 2.0547 mW / 3.13 dBm
  Module temperature                        : 0.00 degrees C / 32.00 degrees F
  Module voltage                            : 0.0000 V
  Alarm/warning flags implemented           : No

• Digital Diagnostic Monitors monitor received power, bias current, supply voltage and temperature. Additionally, alarm and warning thresholds must be written as specified in this document.

References

• SFF-8472 Rev 12.2 Diagnostic Monitoring Interface for Optical Transceivers
• 光通讯：光纤、光模块及光接口常用知识
• SFF-8665 Rev 1.9 QSFP+ 28 Gb/s 4X Pluggable Transceiver Solution (QSFP28)
• SFF-8436 Rev 4.8 QSFP+ 10 Gbs 4X PLUGGABLE TRANSCEIVER
• SNIA, Storage Networking Industry Association
• SNIA Public Documents
• Cumulus Networks Official Website
• Wiki - American Wire Gauge, AWG
• SFF-8024 SFF Committee Cross Reference to Industry Products
• 100G & 25G Plugfests: What we learned - Cumulus Networks

社群服務

本人的文章大多都會發布在 SDNDS-TW。這社團文章都跟 SDN/NFV 國內外產業新聞或資訊有關，有任何技術問題也歡迎在上面詢問。