HP StoreFabric SN1100E White Paper

Technical white paper

Converged Networks and Fibre Channel over
Ethernet

Table of contents

Abstract 2

Introduction 2

Converged networks 2

Data Center Bridging 3
Fibre Channel over Ethernet (FCoE) 3

Challenges for end-to-end network
convergence 4

Servers 4
Direct-attach storage 5
Storage Area Network 5
iSCSI: SANs using TCP/IP networks 5
Cluster interconnects 5

Approaches to converged data center
networks 5

Convergence strategies 6
Cost structure 7
Congestion and flow control 7
FCoE and DCB progress and challenges
ahead 8
Using HP Flat SAN technology to
enhance single hop FCoE 9

Evolution of storage 10

Conclusion 11

For more information 12

Abstract

In this paper we examine requirements for converged networking up to the server edge and beyond for end-to-end
network environments. We want you to understand how the HP vision for converging technology, management tools,
and partner product portfolios aligns with those requirements. We also compare HP and Cisco approaches to converged
networking so you can see the likely outcomes of the two strategies. If you are a senior executive, CTO, CIO, IT manager,
or business manager looking to deploy end-to-end converged networks in the next few years, this white paper can help
you make more informed decisions about converged networking in your IT environment.

Introduction

Traditional data centers typically have underused capacity, inflexible purpose-built resources and high management
costs. Infrastructure designs in such data centers include separate, heterogeneous network devices for different types
of data. Each device adds complexity, cost, and management overhead. Many data centers support three or more types
of networks and therefore require unique switches, network adapters, and network management systems to unify the
networks.

Network convergence in the data center is a simpler and more economical solution than using separate purpose-built
networks for data, management, and storage. Network convergence simplifies data center infrastructure by
consolidating block-based storage and traditional IP-based data communications networks onto a single converged
Ethernet network.

To achieve network-wide convergence, the IT industry has proposed and ratified the IEEE 802.1 Data Center Bridging
(DCB) network protocol standards. The industry as a whole is deciding which implementation paths to pursue. In this
paper we look at issues and choices IT organizations and vendors face when implementing these standards in
networking products and data center infrastructures.

Converged networks

To better understand the current state of data center networking and the difficult tradeoffs facing IT organizations
today, we should look at FCoE and DCB network standards. Protocol standards ratified by the IEEE 802.1 Data Center
Bridging Task Group
infrastructure. Attempts to create end-to-end converged networks over the past decade have used the Fibre Channel
Protocol, InfiniBand, and iSCSI. All have found their place in the market; but for both technological and business reasons,
none have gained widespread acceptance as the Converged Network standard.

In compliance with ratified industry standards, HP has successfully implemented converged Fibre Channel over Ethernet
(FCoE) networks at the server edge using top-of-rack (ToR) switches, Virtual Connect (VC) FlexFabric module, FlexFabric
Adapters, and Converged Network Adapters (CNAs). The server edge is the first hop for networks in multi-hop or multi­switch network environments. The next major challenge is to extend that convergence throughout the data center
network.

Figure 1 shows a single DCB-compliant network carrying IP, storage (FCoE), and cluster traffic using RDMA over
Converged Enhanced Ethernet (RoCEE). You can read more about RoCEE and the expected trends in clustering in the
“Cluster interconnects” section later in this paper.

Figure 1: Converged network, storage, and cluster traffic flows over 10GbE links.

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affect network hardware, architecture, and behavior in converged end-to-end network

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You can get more information o n the IEEE 802.1 DCB Task Group at http://www.ieee802.org/1/pages/dcbridges.html

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