1、 TIA-942-A-1 (Addendum to TIA-942-A) March 2013Telecommunications Infrastructure Standard for Data Centers Addendum 1- Cabling Guidelines for Data Center Fabrics ANSI/TIA-942-A-1-2013 APPROVED: MARCH 26, 2013 NOTICE TIA Engineering Standards and Publications are designed to serve the public interest
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22、. THE FOREGOING NEGATION OF DAMAGES IS A FUNDAMENTAL ELEMENT OF THE USE OF THE CONTENTS HEREOF, AND THESE CONTENTS WOULD NOT BE PUBLISHED BY TIA WITHOUT SUCH LIMITATIONS. ANSI/TIA-942-A-1 i TELECOMMUNICATIONS INFRASTRUCTURE STANDARD FOR DATA CENTERS ADDENDUM 1 CABLING GUIDELINES FOR DATA CENTER FABR
23、ICS Table of Contents FOREWORD . ii 1 SCOPE 1 2 DEFINITIONS 1 3 TRADITIONAL SWITCH ARCHITECTURE 2 4 MULTIPLE CONNECTIONS . 4 5 DATA CENTER SWITCH FABRICS . 5 5.1 Data center fabric fat-tree 6 5.2 Data center fabric full-mesh 10 5.3 Data center fabric interconnected meshes 12 5.4 Data center fabric c
24、entralized switch . 13 5.5 Data center fabric virtual switch . 15 List of Figures Figure 1: Example of traditional three-tier data center switch architecture 2 Figure 2: Example of ANSI/TIA-942-A cabling topology 3 Figure 3: Examples of redundant connectivity 4 Figure 4: Fat-tree example . 6 Figure
25、5: Fat-tree with port extenders example . 7 Figure 6: Example of use of structured cabling for fat-tree switch architecture 8 Figure 7: Interconnected fat-tree pods example 9 Figure 8: Full-mesh example . 10 Figure 9: Example of use of structured cabling for full-mesh switch architecture 11 Figure 1
26、0: Interconnected meshes example 12 Figure 11: Example of use of structured cabling for interconnected mesh fabric . 13 Figure 12: Centralized switch example . 13 Figure 13: Example of use of structured cabling for centralized switch fabric 14 Figure 14: Virtual switch example . 15 Figure 15: Exampl
27、e of cabling for fabric virtual switch architecture . 16 ANSI/TIA-942-A-1 iiFOREWORD TIA standards documents are developed within the Technical Committees of the TIA and the standards coordinating committees of the TIA standards board. Members of the committees serve voluntarily and without commissi
28、on. The companies that they represent are not necessari-ly members of the TIA. The standards developed within the TIA represent a consensus of the broad expertise on the subject. This expertise comes from within the TIA as well as those out-side of the TIA that have an expressed interest. The viewpo
29、int expressed at the time that this standard was approved was from the editors experience and the state of the art at that time. Users are encouraged to verify that they have the latest revision of the standard. This Addendum has been prepared by the TR-42.1 Subcommittee and approved by TR-42.1, the
30、 TR-42 Engineering Committee and the American National Standards Institute (ANSI). There are no annexes in this Addendum. ANSI/TIA-942-A-1 1 1 SCOPE This Addendum specifies recommendations for telecommunications cabling to support data center switch fabrics. 2 DEFINITIONS For the purpose of this Add
31、endum the following definitions apply. access switch: A switch used to connect devices, such as servers, to a local area network. aggregation switch: A switch that aggregates network traffic to and from access switches and that may also connect to network service devices (e.g., load balancers, netwo
32、rk appliances, firewalls). blocking switch fabric: A switch fabric that does not have sufficient bandwidth to ensure that any port can communicate with any other port in the switch fabric at the full bandwidth capacity of either port. centralized switch fabric: A data center switch fabric architectu
33、re in which the switch fabric is implemented in a single centralized switch. core switch: A backbone switch at the highest hierarchical layer of a network. fat tree, fabric: A switch connection topology where each access switch is connected to every interconnection switch within the fabric. full-mes
34、h, fabric: A switch connection topology where each switch is directly connected to all other switches within the mesh. interconnected mesh fabric: A switch connection topology in which pods, each containing a full-mesh fabric, are connected using interconnection switches. interconnection switch: A s
35、witch used to connect access switches, or lower level interconnec-tion switches, in a fabric. leaf and spine switch fabric architecture: See fat tree, fabric. leaf switch: An access switch in a leaf and spine switch fabric architecture. non-blocking switch fabric: A switch fabric that has sufficient
36、 bandwidth to ensure that any port can communicate with any other port in the switch fabric at the full bandwidth capacity of either port. over-subscribe (bandwidth): The assignment of more traffic to a link than the bandwidth capaci-ty of the link. pod, data center: A modular subset of the data cen
37、ter. point-to-point cabling: Direct cabling between equipment (e.g., direct connection between two switches using a cord). port extender: A device that provides additional ports to the controlling switch to which it is connected. spanning tree protocol: Link management protocol that provides path re
38、dundancy while pre-venting undesirable loops in the network. spine switch: An interconnection switch in a leaf and spine switch fabric architecture. switch fabric: A network topology where devices connect with one another using network switches over multiple paths. ANSI/TIA-942-A-1 2virtual switch f
39、abric: A switch connection topology in which a switch fabric is formed by inter-connecting multiple switches to form a single large virtual switch. 3 TRADITIONAL SWITCH ARCHITECTURE Figure 1 provides an example of the traditional three-tier data center switch architecture. Figure 1: Example of tradi
40、tional three-tier data center switch architecture Some of the characteristics of the traditional three-tier switch architecture are: Backup connections (the dashed red lines in figure 1) to access switches are not active due to spanning tree protocols used to prevent routing loops (some protocols do
41、 not have this limitation) Connections are typically over-subscribed (i.e., more traffic assigned to the link than the bandwidth capacity of the link) When access switches are located in the EDA (i.e., top of rack), more switch ports may be available in each cabinet than necessary Traffic between tw
42、o access switches may need to traverse as many as three intermedi-ate switches The traditional architecture is well-suited for traffic between servers on the same access switch and from servers to external destinations. However, it isnt suitable for large virtualized data centers where compute and s
43、torage servers may be located anywhere in the data center. All cabling for the traditional architecture follows the hierarchical cabling topology specified in ANSI/TIA-942-A. See figure 2 for an example. ANSI/TIA-942-A-1 3 ENIMCICCPICCPHC HCEO EOEOEOAccess provider or campus cablingHCESMDAIDAIDAHDAH
44、DAZDA ZDATREDA EDA EDA EDAHorizontalcabling for spaces outside computer roomhierarchical backbone cablinghorizontal cablingcross-connectinterconnectionoutletLEGENDTelecom spaceHCHDAEOEO EOEDA EDA EDAHCHDAEOEO EOEDA EDA EDACP consolidation pointEDA equipment distribution areaENI external network inte
45、rfaceEO equipment outletES entrance room or spaceHC horizontal cross-connectHDA horizontal distribution areaIC intermediate cross-connectIDA intermediate distribution areaMC main cross-connectMDA main distribution areaTR telecommunications roomZDA zone distribution areaoptional backbone cablingbetwe
46、en peer level cross-connectsFigure 2: Example of ANSI/TIA-942-A cabling topology ANSI/TIA-942-A-1 44 MULTIPLE CONNECTIONS Compute and storage servers often have multiple connections to provide redundancy, additional bandwidth, or to support different functions. The connections may be to a single swi
47、tch, to mul-tiple switches within the same network, or to multiple switches in different networks. See figure 3. AccessSwitchMultiple connections to the same switchAccessSwitchAccessSwitchNetworkMultiple connections to different switches on the same networkAccessSwitchAccessSwitchMultiple connection
48、s to different switches on different networksServerServerNetworkNetworkNetworkServerFigure 3: Examples of redundant connectivity ANSI/TIA-942-A-1 5 5 DATA CENTER SWITCH FABRICS Data center switch fabric architectures are intended to provide low-latency and high-bandwidth communication between any tw
49、o points in the switch fabric. Data center switch fabric architec-tures typically use only one or two tiers of switches. These switches have large numbers of con-nections to other switches. These connections are all active to provide multiple paths that mini-mize latency and to provide maximum switch fabric bandwidth. Data center switch fabric architectures can be accommodated using the cabling topology speci-fied in ANSI/TIA-942-A. Some data center switch fabric architectures require backbone cabling between peer level distributors, for example bet
