Communication within Clouds: Open Standards and Proprietary Protocols for Data Center Networking Conference: Communications Magazine, IEEE (Volume:50, Issue: 9 ) Authors: Sher Decusatis, C.J. ; Carranza, A. ; Decusatis, C.M. 1

Introduction 2 來源資料：

SPANNING TREE PROTOCOL AND MULTICHASSIS LINK AGGREGATION Spanning Tree Protocol (STP) – layer 2 switching protocol used by classical Ethernet that ensures loop-free network topologies by always creating a single path tree structure through the network. Link Aggregation Group (LAG) – allows two or more physical links to be bonded into a single logical link, either between two switches or between a server and a switch. 3

TRILL TRILL is the Transparent Interconnection of Lots of Links. TRILL runs a link state protocol between devices called routing bridges (RBridges). TRILL Header 4 “Outer Header” Hop-By-Hop Header TRILL Header“Inner Header” original Ethernet Frame Including Ethernet Header payload TRILL 原先封包樣子

TRILL(cont.) 5 L2L3payload RB5 MACRB2 MACRB5 MACRB2 MACMAC DstMAC srcpayload MAC DstMAC srcpayload

Ethernet Fabric 在 Layer 2 資料鏈結層施行 Layer 3 網路層 的路由機制，支援多條傳輸路徑同時運作， 讓內網流量快速水平流通，打造低延遲網 路架構。 Ethernet Fabric 支援伺服器之間的水平傳輸 流向 6 來源資料：

Ethernet Fabric(cont.) 7 來源資料：

Ethernet Fabric(cont.) 8 來源資料：

Ethernet Fabric(cont.) 9 來源資料：

SOFTWARE-DEFINED NETWORKING AND OPENFLOW The OpenFlow standard moves the network control plane into software running on an attached server or network controller. The flow of network traffic can then be controlled dynamically, without the need to rewire the data center network. In cloud computing environments, OpenFlow improves scalability and enables multi-tenancy and resources pooling, and will likely co-exist with other Layer 2/3 protocols and network overlays for some time. 10

Conclusion In this article, we have presented an overview of layer 2 and 3 protocols that may be used to address the unique requirements of a highly virtualized cloud data center. That enhance features of a flattened layer 2 network (TRILL) or have the potential to enhance future systems (SDN). 11