Cable Backplane for Open RackOCP Rack & Power Group DiscussionMay 8, 2019

Francis LamDirector, Intelligent Computing Product ManagementHuawei Technologies

40-U Server/BBU

Modules

TOR Switch

48VDC PSU

Liquid Cooling Manifold

48VDC Bus Bar

High Speed Cable

Backplane

Conforms to Open Rack v2.1 Specification

Enhanced Open Rack for Huawei Cloud

Rear ViewFront View

Blind-Mate

Change

To adopt RU to

increase density

Recommendation

ORv3 to allow flexibility

for RU and OU

Change

Move TOR from top to

center for SI

Recommendation

ORv3 to allow flexibility

TOR, PSU location

Cabling Topology

Customize TOR Switch Cable

Backplane

Server Node

C C C CNIC

SFP/QSFP Connector

CCable Connector

Solution 1:

Blind-mate

Custom

TOR Switch

Solution 2:

Octopus

cable to

standard or

custom

TOR switch

TOR Switch Adaptor Cable

BackplaneC

Standard TOR

Switch

Server Node

CNIC

Change

Adopt cable connector

on TOR and backplane

Recommendation

ORv3 to allow flexibility

for connections

between backplane

and TOR

Cable Solution1 Example

Server Node 1TOR Switch 1 TOR Switch 2 Blind Mate Connector

NIC1

NIC2

BMC

CPU

Connector

CPU

Rack Side Nodes

TOR Switch Adaptor Cable

BackplaneC

Standard TOR

Switch

Server Node

CNIC

Cable Backplane Solution

Connector to Cable Backplane

Cable Backplane

Cable Backplane to TOR • The physical location of the cable

backplane with respect to the rack

• The opening dimensions and locations

and boundary conditions for the cable

backplane connectors

• The physical location and boundary

conditions of the Cable Connector with

respect to the compute module chassis

• Supplier and model of connectors to allow

innovation

• Cabling topology to TOR – e.g. custom

switch with single connector vs. standard

switch custom switch; octopus cable vs

custom cable with single switch side

connector

Recommendation

ORv3 to Define

Recommendation

ORv3 to allow flexibility for

Cable Backplane Design

TOR Switch Management Switch

TOR Switch

Connectors to Server Node

• 16 pairs high speed SERDES, support 25Gb NRZ,56G PAM4

• AWG30 for 25G lines, AWG28 for 56G lines

• 2 pairs SERDES for BMC Gb Ethernet

• 1 pair for I2C management

• 1 present signal

• 1 throttling signal

Connectors to TOR Switch

• 8 x 40 pairs high speed SERDES, support 25Gb NRZ,56G PAM4

• 32 pairs for stack

Connector to Management Switch

• 2 x 40 pairs Gb SERDES;

• 160 IO signals

Design may be subjected to change

Change

• 2 data TOR Switch

• 1 management Switch

• 40 Server Nodes