FCoE VS FIP
FCoE 主要是將 Fiber Channel 的 資料封裝在 Ethernet 但我們在做 FCoE 傳輸時實際上會用到2種協定 Protocol 1.FC 初始化協定(FIP: FC Initialization Protocol)和 2. FCoE(Fibre Channel over Ethernet) 協定.
1.FCoE Initialization Protocol (FIP)
圖片出自於 http://www.t11.org/ftp/t11/pub/fc/bb-5/08-208v1.pdf
FIP 協議功能包括 Discovery,Login,Logout 等功能.
Discovery Phase
- Provides visibility between ENodes and FCFs (FC Forwarder)
“Same” as today plus perhaps some extensions- Addressing Capabilities
- Possible Duplicate MAC detection
Login Phase
- Creates association between ENode and FCF
Two allowed alternatives- FPMA (i.e., Mapped)
- SPMA
- Works with FLOGI, FLOGI ACC, LOGO, …
2.FCoE Protocol
圖片出自於 http://www.t11.org/ftp/t11/pub/fc/bb-5/08-208v1.pdf
Data Transfer Phase
- PLOGI/PRLI
- All other FC protocol frames (ELS, FC4 ULPs. etc.)
上面講了很多的協定,很多其實我也不是很清楚,大致上就是一開始建立連結時所使用的是 FIP 的協定,之後的資料傳輸才是透過 FCoE 的協定.有興趣深入了解 FIP 和 FCoE 的可以參考這一篇文章裡面對於 FCoE 的架構說明的很清楚 http://www.snia.org/education/tutorials/2008/spring/networking/Hufferd-J_Fibre_Channel_Over_Ethernet.pdf
補充資料
FIP Protocol for FCoE/VN2VN Networks(FC-BB-6)
FC-BB-6 定義 FCoE Direct End Node to End Node(也叫 FCoE VN2VN) 的連結方式.FIP 的協定多了一種為 FCoE VN2VN .
Discovery Phase
- FCoE (w/o VN2VN)
- FCFs Discover each other & form a Fabric
- ENodes Discover FCFs & Potential VN_Port <- -> VF_Port pariring
- FCoE VN2VN
VN2VN capable ENodes Discover each other
Login Phase
- FCoE (w/o VN2VN)
ENodes chose among discovered FCFs’ Ports for Virtual Link connections - FCoE VN2VN
VN2VN capable ENodes chose among discovered VN2VN Ports for Virtual Link connections