ASHRAE Journal - June 2019 - 56

TECHNICAL FEATURE

referenced to speed implemenFIGURE 2 Example of a DCIM connective framework of a data center.
tation and drive standardization across the industry. A comCooling System
mon protocol makes that proUPS
Room
DC
Room
Cooling
Chilled Water Cooling Water Condenser
Outside
Chiller
CRAH Units CRAH Units
Tower Fan
Pumps
AHU
Pumps
Water Pumps
cess of data aggregation simpler
Power
Power
VFD
VFD
VFD
VFD
VFD
Meter
Meter
and lower cost.
Flow
Flow
Meter
Meter
ASHRAE TC 9.9 engaged
with the industry stanBACnet
dards body the Distributed
Modbus Queries Modbus Queries
Data
Aggregator
Management Task Force
Ethernet SNMP
Modbus
Panel
Backup
(DMTF), as an alliance partBoards
Chiller
BACnet
MSTP
ner, in order to promote
Database
UPS
PDU
LAN
industry adoption of the
Modbus Other Building
proposed sensors. The DMTF
POU
Systems
DCIM
creates open manageability
IT Load
standards for traditional and
Database
Data
emerging IT technologies. The
Center
DMTF Redfish implementation of CITE provides the
proper schema mapping, physical context, and reading control;
properties. All sensors and respective naming conven* Network layer provides an end-to-end logical adtions provided as part of CITE have been adopted and
dressing system so that a packet of data can be routed
accepted into the DMTF Redfish API Schema, release
across multiple networks;
2018.3. Interested readers are referred to the DMTF
* Transport layer provides host-to-host communicaRedfish Resource and Schema Guide2 for details on the tion between end devices through a network;
implementation.
* Session layer provides the mechanism for opening,
closing and managing a session between end-user apDCIM Logical Layers
plication processes.
The importance of DCIM is to bridge the physical and
* Presentation layer is responsible for how an applilogical systems together to create a standardized envication formats the data to be sent out onto the network,
ronment and manage the interdependencies between
the functionalities include data conversion, translation,
the subsystems in the ecosystem. Systems of the data
compression, and encryption; and
center communicate in different languages (i.e., proto* Application layer is responsible for the input and
cols), as seen in Figure 2, and are not easily understood
output of the data when a user is running an application.
between technologies. It is imperative that all the sysThe DCIM software resides in the Application Layer.
tems work in harmony between the different layers to
The Application Layer works as the user interface,
create interoperability for the entire data center.
through for example, web browsers (Hypertext Transfer
Standardization of protocols in the data center is criti- Protocol). Understanding the connectivity methodolcal to optimize management between all layers in the
ogy is crucial to bridge the gap between the physical and
data center. Interoperability of the ITE and infrastruclogical layers.
ture layers allows cohesion for the total system instead of
Monitoring a single device, with a standard protocol,
operating each layer independently. In many cases, the
is relatively easy but mixing several subsystems together
DCIM ecosystem follows a TCP/IP model consisting of:
adds a level of complexity that most data center opera* Physical layer that defines the physical and electri- tors are not prepared to undertake. When properly
cal characteristics of the network;
implemented, DCIM software can address this complex
* Data link layer defines the frame formats for trans- issue by integrating at key points tiers and levels across
mission, media access control, error detection, and flow the data center ecosystem.
56

ASHRAE JOURNAL

ashrae.org

J U N E 2 0 19
https://www.ashrae.org/
ASHRAE Journal - June 2019

Table of Contents for the Digital Edition of ASHRAE Journal - June 2019
