Automatic Transfer Switch (ATS) PDU
For colocation customers that have hardware without redundant power supplies
, rather than buy new equipment to achieve redundancy at the hardware level, or to eliminate downtime during PDU
maintenance, you can use an ATS PDU that automatically switches to a secondary power source if the primary power source to the PDU
is terminated. The dual AC power
inputs can be connected to two power sources, whether they are utility, generator, or UPS
. In most data centers, the primary power input plugs into the primary UPS
system, which must be an On-Line UPS System
. The secondary input plugs into the secondary UPS
system. Ideally, the UPS
systems should be connected to separate circuits. The PDU
monitors voltage and frequency, automatically switching to the secondary input if the primary input deviates from the designated operating.
When evaluating IT, colocation, and network services, it is important to understand how well the system or services has historically performed. Availability refers to the period of time that a data center, computing resource, or application is available for use and not offline for maintenance or a failed state
. UpStack measures Availability as the percentage of time that the services are available over a period of time. Availability should not be confused with Reliability
. Whereas Reliability
represents the predictability of how a system is designed to perform, Availability is a measure of how a system has actually performed historically. Similar to an aircraft that is designed to be highly reliable, if the maintenance on that aircraft is inadequate, or the pilots responsible for operating the aircraft are not qualified, that highly reliable aircraft may crash.
The amount of capacity you have to transmit data on a network – whether it is between two locations or multiple locations.
The minimum contracted payment owed by a customer. In NNN Colocation contracts, in addition to Base Rent, the customer is responsible for paying certain pro rata costs associated with operation of the data center and the building within which it operates; this would include all expenses such as property taxes, insurance premiums, repairs, utilities, maintenance, security, and direct power consumption. In Modified Gross Colocation contracts, the Base Rent will typically include all such expenses, with the exception of the power consumed by the customer's IT equipment and its pro rata share of power required to cool its IT equipment. In Gross Colocation contracts, the Base Rent is the absolute total payment to cover every expense related to the customer's colocation requirement.
A Basic PDU is a cost-effective way to deliver reliable power to IT hardware from a single power input (most often in data centers from a UPS system
) with multiple output receptacles (breakers) that take higher voltage (often 480v) power from a UPS system
and convert it to a lower voltage (often 208v or 120v) which is the voltage required by IT hardware. A basic PDU is the simplest way to distribute data center power from a UPS or non-UPS-supported power supplies to multiple Server Racks
Also known as a "Biscuit Block" jack, a Biscuit Jack is a device used for mounting network cabling with RJ45 connectors
Sometimes referred to as a Blade Enclosure, a Blade Chassis is a device mounted into a Server Rack
that can hold multiple Blade Servers
. Unlike Rack-Mounted Servers that are mounted directly to a Server Rack
and require individual Power Supplies
, Fans, and Networking harware, Blade Servers
are installed in a Blade Chassis that centralizes power, cooling, and network hardware across all of the Blade Servers installed within it.
A modular Server, that does not consist of the power, cooling, and network equipment found in traditional Rack-Mount Servers. A Blade Server is installed within a Blade Chassis
that centralizes power, cooling, and network equipment to support multiple Blade Servers installed within the Chassis
. As a result of minimizing the amount of components needed for each server, and centralizing them on a common Blade Chassis
, Blade Servers may minimize physical space requirements in Server Racks
(and data centers) and increase the power utilization of each Server on the aggregate.
Often referred to as a "whip," "power whip," or "PDU cable," a branch circuit is the final electrical circuit between the outlets in a Power Strip
located on a Server Rack
and the circuit breaker located in a RPP
Branch Circuit Monitoring
Branch Circuit Monitoring enables colocation providers to meter/monitor multiple Branch Circuits
to multiple colocation customers within a data center. This enables colocation providers to monitor the power consumption of its customers at the Server Rack
for the purposes of tracking power circuit utilization and passing through electrical consumption costs to customers with contracts that provide for electrical pass throughs, such as Triple Net
and Modified Gross
See: Ladder Rack
Cable Retaining Post
A Ladder Rack
accessory that provides extra cable depth for additional cabling that mounts to an existing Ladder Rack
See: Ladder Rack
Capital Expense (CAPEX)
CAPEX refers to funds used to build, acquire, or upgrade a physical asset such as servers
, server racks
, generators, or buildings. These expenses can include anything from purchasing or repairing a power cable to constructing an entire data center
Carrier Dependent Colocation
A form of Data Center Colocation
whereby the network service provider (or "Carrier") provides colocation services within its own data center exclusively to customers of its network services.
Carrier Ethernet Exchange
Compared to older technologies, Ethernet
provides lower cost per bit, greater bandwidth scalability, and simpler operations. A Carrier Ethernet Exchange enables Ethernet
buyers and sellers to discover, transact and interconnect to each other, enabling service providers to cost-effectively scale Ethernet
deployments and expand services for customers, and businesses to scale networks to keep up with application and bandwidth
demands. Data centers that offer Carrier Ethernet Exchange services give buyers and sellers of Ethernet
services an easier and less costly way to connect and extend their Ethernet
Carrier Neutral Colocation
In contrast to Carrier Dependent Colocation
, where a carrier itself is providing colocation
services dependent on using its own network, a Carrier Neutral Colocation data center permits any carriers to become colocation customers within its data center to provide network and other services to other customers located within the data center. Carriers utilize a centralized Meet Me Room (MMR)
where they interconnect
with other colocation customers. The density of carriers within a singular data center often drives down network expenses for colocation customers resulted in a significantly lower TCO
Cat5 Cabling is a UTP
type of cabling with an RJ-45 Connector
used to connect computers and servers to modems, networks, and ISPs. Although the Cat5 cable can handle up to 10/100 Mbps at a 100MHz bandwidth (which was once considered quite efficient), Cat5 has become obsolete in recent years due to newer versions of Cat cables Cat5E
that transfer data at much higher speeds with designs with significantly less Crosstalk
“Cat5 Enhanced” cabling replaced Cat5
as the standard cable about 15 years ago and is still the most commonly used in today's data centers. Cat5E can transfer data up to 10 times faster than Cat5
) at 100 MHz
with a significantly greater ability to traverse distances without being impacted by crosstalk
Category 6 cabling arrived just a few years after Cat5E
cabling and is ten times faster (10Gb at 250MHz). Further, it has an internal separator that further mitigates the impact of crosstalk
. Cat6 cabling is most often used for network backbones due to its distance limitations and cost factors. If a Cat6 cable distance exceeds 164 linear feet, its speed rapidly decays to the same gigabit ethernet
speed of Cat5E
Category 6A cables are the latest iteration of UTP ethernet
cables that further mitigates crosstalk
through exceptionally thick plastic material and extends its 10Gb speed beyond the limitations of Cat6
cables to 328 feet.
Ceiling Clear Height
Clear Height in Colocation Data Centers refers to the lowest portion of the ceiling in the data center that may interfere with racks with varying heights. It is important to confirm that the lowest portion of the ceiling in the proposed Colocation Data Center
meets the height requirements for Server Racks
Central Processing Unit (CPU)
Also known as the Processor, or the "Chip," the CPU processes the information and instructions used by a computer. It is basically the brains of a computer. The speed with which a CPU processes data and instructions is measured in either megahertz
Children’s Internet Protection Act (CIPA)
CIPA is a federal law enacted to address concerns about access to offensive content over the internet by minors on library and school computers. It requires K-12 schools and libraries to incorporate filters and other measures to mitigate the risk of minors from receiving or retrieving harmful content
Children’s Online Privacy Protection Act (COPPA)
Instituted by the FTC in 2000, COPPA applies certain requirements on website operators to enforce privacy for children under 13 years old. The primary goal is to put parents in control of the information that websites collect from their children.
A Breaker is an electrical switch designed to protect an electrical circuit form damage caused by overload or short circuit. It automatically interrupts the power circuit in case of failures. Once the problem has been resolved, a Breaker can be reset to resume normal operation. Breakers come in a wide variety of sizes and specifications, depending on the circuit that they need to protect.
In wholesale colocation
, the customer is often required to purchase and install its own breakers since the colocation vendor will typically not know the individual circuits required to each server rack
Closed Circuit Television (CCTV)
The most common type of video surveillance used in data centers. These are the video cameras you often see in many areas within and around the perimeter of data centers that transmit signals to monitors located in security offices within the data center. These cameras may be designed to pan, tilt, zoom, and can be constantly monitoring and saving footage or can be activated due to motion detected within its range.
A single integrated digital platform that aggregates multiple Anything as a Service (XaaS)
cloud providers. A Cloud Broker platform enables executives within an organization to log into a single portal to broker and administer multiple XaaS
offerings to one or more departments within the organization, helping to manage challenges with Cloud Sprawl
. Standard features include a centralized cloud management portal, reporting, and system and data portability between downstream cloud providers.
Cloud Computing is a model for accessing computing resources (processors, memory, storage) over the Internet or via private network circuits in and between data centers and other facilities. There are five key characteristics of cloud services as defined by NIST which are a) on-demand self-service, b) broad network access, c) resource pooling, d) rapid elasticity, and e) measured service. There are multiple cloud deployment models including Public Cloud
, Private Cloud
, Virtual Private Cloud
, Community Cloud
, and Hybrid Cloud
Cloud Native Application
An application designed specifically to run on and benefit from cloud computing
Also known as virtual servers
, Cloud Servers enable customers to utilize or rent virtual portions of a physical server
. Instead of renting the full capacity of a physical, dedicated server
, customers can rent smaller virtual portions of that same physical server
. With Cloud Servers, customers only pay for on-demand increments of server capacity and have the benefit of infinite elasticity, scalability
, and flexibility to scale IT resources up, down
, in, or out
depending on need and avoid paying for idle infrastructure or underutilized resources.
The uncontrolled proliferation of cloud services being consumed within an organization by its employees. When employees or departments purchase and consume various SaaS
products without proper controls in place. Examples include the marketing department using Adobe Cloud, engineering using AWS, accounting using Intuit Cloud Services, sales using Salesforce.com, and others using gmail, dropbox, etc. This can lead to compliance concerns, unnecessary license fees, and IT's inability to gauge total organization IT workloads. Cloud Broker
models have been created to control and better manage the cloud services that organizations consume.
Coaxial Cable (COAX)
Coaxial cable is used as a transmission line for radio frequency signals and provides much greater bandwidth
An arrangement whereby a business (customer) pays a 3rd party (Colocation Provider
) for use of floor space
or rack unit
space in a data center
for the customer's IT equipment such as server racks
, an allocation of power for its IT equipment
, and interconnection
to other service providers, networks, or ISPs
. The Customer effectively outsources the complete operation of the physical building, security, and electrical and mechanical infrastructure to a 3rd Party
that specializes in designing, building, and operating data centers. The Customer owns and operates everything that resides within its floor space
, and the Colocation Provider
is responsible for ensuring that its IT equipment never fails due to environmental events or power failure.
As the name suggests, a Colocation Cage is a physical barrier within a multi-tenant data center
that adds additional security for customers by separating them from other customers in the colocation data center
. Although the electrical and mechanical systems may still be shared between other customers in the data center, some customers prefer to pay for this additional layer of security to mitigate the risks of other customers endangering their equipment.
Most colocation vendors will provide customizable cages that surround customer racks and limit access to only those approved by the customer. A typical Cage consists of cage walls, and one door with a standard mechanical lock. Customers can typically customize the security using additional layers of security leverage Biometrics, Retina Scans, Keycards, etc. There is typically a minimum footprint or minimum number of Rack Equivalents required for a dedicated cage to a customer.
In carrier Neutral Colocation facilities, customers are able to connect with networks, carriers, ISP’s and other customer by virtue of Interconnection. This enables customers to interconnect with global networks and ISPs for peering, transit and traffic exchange requirements, as well as other service providers that provide private cloud, public cloud, and financial services. This is often charged by the Colocation provider on a non-recurring and monthly recurring basis. For a deeper dive check out Understanding Colocation Economics.
A customer Colocation Suite is a dedicated room for Colocation Customers. It is physically separated from other Colocation Customers by floor to ceiling walls. Customers with high security requirements will often prefer a Colocation Suite to a Colocation Cage. Although a customer in a Colocation Suite will be physically separated from other customers, it does not mean that the infrastructure supporting the Colocation Cage is dedicated to the customer. It is important to determine what infrastructure (if any) is truly dedicated to the customer within a Colocation Suite.
Computer Room Air Conditioner (CRAC)
A CRAC unit is a common type of cooling system in data centers that. They are the large units often seen on the perimeter of a data center room. A CRAC unit is similar to the cooling system in homes and consists of a Direct Expansion (D/X) refrigeration cycle
that is powered by a compressor that is within the unit along with fans that draw air across a cooling coil pumped with refrigerant. This type of cooling is one of the least energy efficient cooling designs in data centers today, but also the lowest upfront CAPEX
for data center operators.
Computer Room Air Handler (CRAH)
A CRAH unit is a common type of heat rejection (cooling) system found in data centers. These units can be most often found on the perimeter of a data center room. Not to be confused with a CRAC unit
that utilizes a compressor and D/X cooling system
within the unit, a CRAH unit has a cooling coil supplied with water (instead of refrigerant) from a chiller plant that is used to reject the heat from return air that enters the CRAH unit from the exhaust of servers and other IT equipment.
Configuration Management System (CMS)
Process for maintaining the configuration of your systems throughout their life cycle to enable a repeatable process required for automation and infrastructure management.
Content Delivery Network (CDN)
A CDN consists of proxy servers that are geographically distributed in multiple locations (data centers or POPs
) to deliver highly available and low latency content to its customers.
Also known as a "Cooling Multiple," and often in correlation with the PUE
of a data center, the Cooling Factor is an additional cost added to Wholesale Colocation
contracts to account for the power used by the cooling system to cool a colocation customer's IT equipment.
When adding a Cooling Factor to a customer's monthly bill, the colocation vendor will submeter a customer’s power consumption, typically via Branch Circuit Monitoring
or at the PDU
s serving the customer's colocation environment, and will multiply the total kWh
during the billing period by the Cooling Factor, to account for the additional cooling expense. For example, a persistent 100kW IT load
over 30 days would be 72,000kWh (100kW x 720hours = 72,000). If the Cooling Factor is 1.5 (a 50% cooling factor) then the total power consumption passed through to the customer is 72,000 x 1.5 = 108,000kWh. If the Normalized kWh Rate
is $.06/kWh the total cost to the customer would be $6,480 (108,000 x .06).
Commercial-off-the-shelf software that is packaged and sold via multiple channels and made widely available from software companies.
A common term used to describe the type of interconnection
provided between two colocation
customers. There are many different types of cross connects such as Local Cross Connects
, Metro Connect
, Campus Connect, and Innerduct Connect.
Crosstalk refers to the interference that occurs when data cables are in close proximity to one another, such as when they are in a cable tray
or server rack
. Crosstalk increases errors and lost packets (among other issues). Due to its propensity for Crosstalk, Cat5
cables have been replaced by newer versions of cat cables (i.e. Cat5E
, and Cat6A
cables) that reduce the impact of crosstalk through a variety of methods, such as better shielding
Data Center Colocation
Data Center REIT
A REIT specializing in owning and operating powered shell and/or colocation data centers
Data Center Tiers
The Uptime Institute
created and maintains a set of ratings applied to the design, construction, and operation of enterprise and colocation data centers. It defines a range of four distinct standards (or data center tiers). These Tiers are Tier 1 Data Center
, Tier 2 Data Center
, Tier 3 Data Center
, and Tier 4 Data Center
See: Data Center
The concept that computing data is subject to the laws of the country in which it is located. This prevents foreign governments form subpoenaing the host country or cloud service provider where the data center is located. Data sovereignty presents technical challenges for companies that move data from on-premises to a cloud service provider. Privacy and data sovereignty laws vary by country. For example, the strictest countries of Germany, France, and Russia dictate that all of its citizens' data is stored within the country's physical borders.
See: Data Center
See: Data Center
Also referred to as Bare Metal Servers, a Dedicated Server is a physical server that is purchased or rented exclusively for the business. Unlike Cloud Servers
, where physical servers are virtualized
to provide shared, virtual environments on-demand for short-term, or unpredictable workloads, Dedicated Servers are utilized by businesses that require higher levels of data security, have compliance requirements, or have more predictable, long-term workloads.
In colocation, a demarcation point (also referred to as a "demarc") defines the hand-off point between a colocation company and a customer. The demarcation point can be at the individual server rack level, a colocation cage, or colocation suite, depending on the size and type of the colocation requirement.
For network interconnection, the demarcation point is the defined location within a patch panel located in a colocation cage or server rack.
Derated Circuit Breakers
A Derated Circuit Breaker value is the safe maximum continuous power draw for a circuit. While its Rated Value (also known as its "Maximum Capacity") is its overload protection tripping threshold, a Derated value is the guideline established by NEMA for its maximum safe sustained power draw, which it has determined to be no more than 80% of its rated value. This provides a 20% safety margin into circuit usage during transient peaks as well as increased power usage during boot up compared to avg operational power usage.
Circuit breakers in data centers are temperature sensitive. They function on the thermodynamic properties of metals and if that breaker is exposed to hot or cold conditions it will not function properly. As a result, electricians must follow NEMA guidelines to derate their circuit breakers depending on the application, installation and intended usage.
For rack-level power in data centers located in North America, the circuit breaker within the PDU for this circuit must be derated by 80% per NEMA ratings. So, this circuit, is in fact, not a 3.6kVA circuit. It is actually a 3.6kVA x 80% = 2.88kVA circuit. To convert this to its kW equivalent, it depends on the efficiency of the power supplies
ultimately delivering the power to the IT hardware.
In Europe and other parts of the world, circuits are simply described at their Derated capacity which helps to avoid confusion as to what capacity is truly available to a customer. It is important in the U.S. to ensure that you are quoted IT Power circuits at their Derated capacity.
DIACAP (DoD Information Assurance Certification and Accreditation Process)
DIACAP was a US Department of Defense (DoD) process to ensure that risk management is applied on information systems. Any service provider that stores, transmits, or display any DoD data must be DIACAP compliant. In 2014, the DoD transitioned the DIACAP process to the Risk Management Framework (RMF).
Direct Current (DC) Power
The majority of power circuits in the data center deliver Alternating Current (AC)
. Direct Current (DC) is the native power used in all electronics (CPU
, disk drives, memory chips). For equipment running directly on DC power, they do not need components to transform the power from AC to DC, which results in less failures and more efficient power distribution.
EC Plug Fan
A new, more energy efficient fan used to reject heat in data centers. EC stands for "Electrically Commutated" which in the most simple terms, is a type of motor driven by DC current
instead of AC current
that is able to manage the speed of the fan by regulating the current.
The term "plug" refers to the location of the fans in a cooling unit, unlike traditional CRAC
units where the fan is located inside of the unit, a plug fan is attached to the bottom below a raised floor
Elasticity (scale in/out)
The ability of an application or computing resource to automatically "scale in or out" by adding or removing virtual machines
or computing resources to manage an increase or decrease in workload.
End of Row Switching
An alternative approach to network switching design whereby, rather than placing an Ethernet Switch
in each Server Rack
, as in the Top of Rack design
, a specific rack is placed at the end of a row of Server Racks
for the purpose of aggregating multiple switches
within that rack to provide network connectivity to the servers within the row.
Essential Power (Cooling) Load
The watts required by cooling equipment to reject the latent heat dissipated from IT equipment and other internal loads in a data center. Essential load is required for calculating aggregate power load
The name coined by Xerox and defined by the IEEE 802.3 subcommittee for a group of network technologies and protocols commonly used for connecting computer systems to form LAN
An ETSI Rack is a standardized Network Rack form factor dictated by The European Telecommunication Standards Institute (ETSI) aimed at defining the housing equipment used to accomodate optical fiber distribution and other netwoork equipment including Splicing and Patching Shelves and Distribution Sub-Racks. An ETSI Rack consists of 4 width dimensions of 150 mm, 300 mm, 600 mm, or 900 mm and 2 depth dimensions of either 300 mm or 600 mm.
FISMA (Federal Information Security Management Act)
FISMA mandates that all US Federal Agencies are required to develop, document, and implement programs to provide information security for the systems that support operations and assets managed both internally and by other agencies or third parties.
Floor Live Load
The Floor Live Load capacity of a data center
determines the amount of forces that cause stresses on a building or structural element, including equipment, people, vehicles, etc. and are measured as pounds per square foot.
The weight of a loaded Server Rack
itself can weigh in excess of 2,000lbs. For this reason, when evaluating a data center it is important to understand whether the building's design Live Load can support the customer's IT equipment. For data centers with raised floor
environments, it is important to not only know the subfloor live load rating, but also the total tile load of the raised floor tiles that will be supporting rack.
One of the most overlooked areas in data centers is Floor Live Load rating. Today's IT systems are demanding higher ratings and some legacy data centers may not be able to support new form factors such as taller racks that can stack greater amounts of hardware within the same square footprint.
Full Service Contract
See: Gross Contract
Gross Colocation Contract
Also known as a Full Service Contract
, this contract type is commonly found in retail colocation
requirements and consists of an all-inclusive rental rate that includes all operating expenses, power costs, etc. whereby the customer shares no risk for any increase in operating expenses over the base amount. In this type of contract the customer knows exactly how much it will pay each month without the risk of additional costs due to increases (or decreases) in utility rates, taxes, operating expenses, etc. Because the colocation vendor is taking on the risk of additional increases in expenses, there is usually a risk premium included in the base rent
which results in substantially higher base rental rates as compared to Modified Gross
contracts where the risks are shared wholly or in part by the customer.
A Server Rack
or Rack Level Requirement
that is the physical height equivalent of one half of a Standard Rack Level Equivalent
, or, roughly 22 Rack Units
HIPAA (Health Insurance Portability and Accountability Act of 1996)
US legislation that provides privacy and security protection of sensitive patient information. All companies that manage patient information must incorporate security measures both physically and digitally for services they provide. HIPAA compliant IT service providers, such as cloud and hosting providers strictly in place and followed.
Hot Swap PDU
A Hot-Swap PDU
is able to make an On-Line UPS System
hot-swappable. Much like a Basic PDU
, The primary power input plugs into an on-line UPS system, and the secondary input plugs into a wall outlet. However, if the UPS
system is taken offline for maintenance, repair or replacement, the PDU keeps the load powered by automatically switching from the primary input to the secondary input. When the UPS system is restored, the PDU will switch back to the primary input.
In contrast to an immutable process whereby a resource is created or destroyed when an automated script is re-run, Idempotency refers to the ability of a system to achieve the same results each time an automated script using the same resources, is re-run. Configuration Management Solutions
such as Ansible
and Chef are examples of Idempotent technologies. When automating scripts this helps removes fears of damaging active systems during automation.
I contrast to Idempotency where resources are modified, Immutability is the concept whereby resources are never to be modified, resulting in new resources created and existing resources to be terminated. Cloudinit and Terraform are two examples of Configuration Management Solutions
that are Immutable.
An Internet Exchange facilitates Peering
via an ethernet
switching fabric. An Internet Exchange enables parties to peer to reduce network costs and enable efficient IP traffic
interchange by aggregating thousands of networks directly at the exchange onto a shared fabric connecting peers at multiple data centers
. This enhances network performance by eliminating network hops
and can reduce bandwidth
IT Power (also referred to as "Critical Power" or "Critical Load") and measured in Watts, Kilowatts or Megawatts refers to the Real Power required (or consumed) by the IT equipment of a colocation customer. In Colocation agreements, a customer typically identifies the total kW required in each Server Rack
and is charged a fee to reserve that power for the customer's exclusive use. IT power is different from Cooling Power (also known as "Essential Power Load
No entries for J
Kilo Volt Ampere stands for 1,000 Volt Amperes.
Also known as a Cable Raceway
or Cable Runway
, a Ladder Rack is a structure shaped like a ladder that is used to distribute and organize network cables such as Fiber
, etc. They are typically mounted to the ceiling of a data center
directly above rows of Server Racks
but can also be mounted to walls, floors, or Server Racks
. Ladder Rack installation is simple and requires little trade experience. To avoid routing cable without damage, many accessories are included with Ladder Racks such as 90-degree bends, waterfalls
and cable retaining posts
. A Ladder Rack is not intended for Branch Circuits
or other electrical cabling due to the risk of electromagnetic interference with the network cables.
Local Cross Connect
A Local Cross Connect is a type of interconnection
available within a single data center that connects a colocation customer with another company or service provider within the same data center via fiber, copper, coax, etc.