2026-09-20 · a-plus, comptia, class-notes
An organisation may have hundreds or thousands of phones and tablets. Some are company-owned; others belong to employees. They're outside the office, easily lost, and each needs the right apps, email settings and…
Class notes · Professor Messer, CompTIA A+ 220-1201 Core 1 · Objective 1.3 (MDM)
Quick reference: the short version of this lesson is the Mobile Device Management cheat sheet, part of Section 1.
By the end of these notes you should be able to:
An organisation may have hundreds or thousands of phones and tablets. Some are company-owned; others belong to employees. They're outside the office, easily lost, and each needs the right apps, email settings and security. Configuring them one by one isn't practical.
A mobile device manager (MDM) — also called mobile device management — is specialised software that lets administrators manage all mobile devices centrally, from one place.
An MDM lets you
Examples
Set rules and parameters for how devices are used
Allowed and forbidden apps
Enable or disable device features
Camera, GPS
Separate corporate and personal data
A partitioned work area on a personal phone
Enforce security policies
Screen locks with a PIN or other unlock method; multi-factor authentication
Push configuration
Corporate email settings, applications
See every device
Inventory with device, user and IMEI details
In short, an MDM can control almost every aspect of a managed mobile device.
BYOD (also called bring your own technology) means the employee owns the phone and uses it for work too.
Benefit
Challenge
The employee carries only one device
Company data must be protected on a device the company doesn't own
No hardware cost for the company
The user's personal data must stay personal and private
Policies are needed for when the phone is upgraded, traded in or lost
The MDM defines which part of the device is home (private) and which is work, and how data in each is protected.
With COPE, some organisations don't allow personal phones for work at all. Instead:
It's managed much like company laptops and desktops. The company decides what's stored on the device, how it's stored, and what happens to the data if the device is replaced or lost.
CYOD adds flexibility: the company provides and manages the device, but the user chooses it from a selection of approved models.
BYOD
COPE
CYOD
Who owns the device
Employee
Company
Company
Who chooses it
Employee
Company
User picks from an approved list
Company control
Limited — the work partition
Complete
Complete (company-owned)
Personal use
Yes — it's their phone
Often allowed
Often allowed
Key concern
Separating work and personal data; privacy
Cost of buying devices
Supporting several models
Note (beyond this lesson): a fourth model, COBO (corporate-owned, business only), allows no personal use at all. It's common for high-security roles and shared devices.
Scenario
Model
Reasoning
A small charity has no budget for phones; staff need work email on the phones they already have
BYOD
No hardware cost, with a work partition protecting the charity's data
A bank needs complete control of every device that holds customer data
COPE (or COBO)
The company owns and fully manages the device
A firm wants control but staff complain about the one model on offer
CYOD
Staff choose from approved models while the company keeps ownership and control
On a BYOD phone, the MDM creates a partitioned area for the organisation:
+----------------------- Employee's phone ----------------------+ | | | | PERSONAL (home) partition | CORPORATE (work) partition | | Photos, personal apps, | Work email, calendar, | | messages, social media | business apps, company files | | | | | Private to the user. | Managed by the MDM: | | The organisation doesn't | policies, protection, | | manage it | removal when needed | | | | +------------------------------+--------------------------------+- The user's personal data stays protected and private.
Note (beyond this lesson): this is often called containerisation. Removing just the corporate partition is a selective (corporate) wipe; erasing the whole device is a full wipe, used for company-owned devices.
Area
What administrators can do
Screen lock
Require one, unlocked with a PIN or another access method
Authentication
Require two-factor / multi-factor authentication, and specify which type
Applications
Allow specific apps, forbid others, and push apps for automatic installation
Device features
Enable or disable features such as the camera and GPS
Corporate email
Configure settings centrally and push them to every phone
The pay-off from central email configuration: the user turns on their phone and their inbox simply works. They don't have to enter any server settings themselves.
Mobile devices live outside the company and are easily lost. So the security team often requires more on them than on office desktops — for example mandatory screen locks and multi-factor authentication.
The console lists every managed device. Typical columns:
Field
Shows
Device name
The phone's name
Platform
e.g. iOS or Android
Username
Who the device is assigned to
Email and contact information
The user's details
IMEI
The device's unique identifier — the International Mobile Equipment Identity
Selecting a device shows its details — for example:
As the device's manager, you can enable or disable features, such as:
Category
Examples
Camera and communication
The camera, FaceTime, voice dialling
Assistant
Siri
Other
Security options, printing options, application options
A user reports their COPE iPhone lost on a train.
Mobile devices are rarely plugged in to anything central, so synchronisation over the air is how their data is backed up — and how it's restored if a device fails, is damaged or needs replacing.
Setting
Options
What's always synced
Some items are preconfigured, such as phone information and messages
Email service
Differs by organisation — e.g. Gmail or Microsoft Outlook — so it's set centrally
Network used
Wi-Fi only, or Wi-Fi and cellular
Data types
Choose individually: calendar, contacts and others
Timing
Different synchronisation behaviour at different times of day
Cellular limits
How much cellular data can be used, and for what
Automatic downloads
Whether they're allowed over mobile data, and the maximum app size that can download over the mobile network
Cellular data can be expensive. Many organisations sync only over 802.11 (Wi-Fi) or the local network to control cost. Mobile devices also have their own settings controlling how much cellular data can be used and for what.
Check the contract with the cellular provider: how much data is allowed, and at what times.
Field engineers have phones on a plan with a small monthly data allowance.
Result: engineers always have current appointments and contacts, and the heavy data waits for Wi-Fi.
Business services such as Outlook, other email, and cloud storage are usually set up in the device's account settings. You provide:
Each account has its own granular sync choices:
Data type
Example
The inbox and folders
Contacts
The address book
Calendars
Meetings and appointments
Reminders
Tasks
Notes
Notes
Settings can differ per service. For example, the Microsoft Exchange account might sync mail, contacts and calendars, while a Google Mail account syncs only mail.
A user needs their company Exchange account and a shared Google Mail account for a project.
Account
Sync
Reason
Microsoft Exchange (corporate)
Mail, contacts, calendars, reminders
The main work account
Google Mail (project)
Mail only
Avoids duplicate contacts and calendars
Both are added in the account settings, each with its own credentials and authentication factor.
Term
Definition
MDM
Mobile device manager — central management of mobile devices
BYOD
Bring your own device — employees use their own devices for work
BYOT
Bring your own technology — another name for BYOD
COPE
Corporate owned, personally enabled — company device, personal use allowed
CYOD
Choose your own device — the user picks from approved company devices
COBO
Corporate owned, business only — no personal use (beyond this lesson)
Partition (work / personal)
Separate areas on one device for corporate and private data
Containerisation
Another term for isolating corporate data in its own area
Policy
A rule set by administrators and enforced on devices
Restriction
A setting that disables a device feature, e.g. camera or Siri
Screen lock
A lock requiring a PIN, password or biometric to unlock
Two-factor / multi-factor authentication
Login requiring more than one type of proof
Push
Sending configuration or apps from the MDM to devices automatically
IMEI
International Mobile Equipment Identity — a phone's unique hardware identifier
Over-the-air (OTA) sync
Synchronising data wirelessly, without cables
Cellular data
Mobile network data, often limited or charged by contract
Account settings
Where email and cloud services are added to a device
Microsoft Exchange
Microsoft's corporate email, calendar and contacts service