Key takeaways
- A DVR turns analog video into digital files at the recorder, an NVR records IP cameras that send their video as a digital stream, and cloud recording keeps the video off site.
- The back of the recorder is the quickest way to tell them apart: round coax plugs usually mean a DVR, network jacks usually mean an NVR, and no recorder at all can mean cloud or in-camera recording.
- When the internet goes down, a DVR or NVR normally keeps recording on site. A cloud system keeps recording if the camera or a box on site stores video in the meantime.
- Existing cable, the number of cameras and sites, upload capacity, the days of footage you need and who maintains the system decide the choice.
- Existing coax can often stay, with a recorder that reads the cameras' analog format or with adapters that carry network and power over coax.
- Change every default password as soon as possible, and before a recorder or camera is reachable from the internet. Keep firmware current, and avoid opening the recorder directly to the internet.
First distinction
What each one is, and how to tell which you have
An analog camera sends a continuous signal down coax, and the DVR turns it into digital files. An IP camera does that itself and sends network data to an NVR. With cloud recording the video goes over your internet connection to a service, either straight from the camera or through a small box on site called a bridge or gateway.
You can usually sort an existing system in a few minutes by looking at the recorder and one camera cable. Nothing has to be unplugged.
| What you see | What it usually is | What else it could be |
|---|---|---|
| A recorder with a row of round, twist-lock coax plugs (BNC connectors) | A DVR with analog cameras | A hybrid recorder, which takes both analog and IP cameras. Coax plugs and network jacks that are both labeled as camera inputs suggest one. |
| A recorder with a row of network jacks, one per camera | An NVR that powers its cameras over the network cable (PoE, Power over Ethernet) | A hybrid recorder, if coax plugs are there too |
| A recorder with one or two network jacks, and cameras plugged into a network switch elsewhere | An NVR recording cameras across the building network | A cloud bridge, if you watch through an online account |
| No recorder. Cameras plug into a switch or join the Wi-Fi, and you watch through a website or app | Cloud recording, or cameras that record to their own built-in storage | A recorder in another room. Ask before assuming |
Side by side
NVR vs DVR vs cloud video storage, side by side
The table shows what differs. It does not score one above another, because the same row can suit one building and limit the next.
| DVR | NVR | Cloud recording | |
|---|---|---|---|
| Cabling | Coax to each camera, usually with a separate power pair, or power over the coax in some HD systems | Network cable, which normally carries power too (PoE) | Network cable or Wi-Fi, plus the internet connection |
| Cameras it works with | Analog cameras in a format the recorder reads. There are several, standard definition and HD | IP cameras the recorder supports, from the same maker or through a shared standard | Usually the service's own cameras or a published list |
| Where footage lives | Hard drives in the recorder | Hard drives in the recorder, or storage the recorder is set up to use | A data center. Some systems also keep a copy at the camera or on site |
| If the internet goes down | Normally keeps recording. Remote viewing stops | Normally keeps recording. Remote viewing stops | With storage at the camera or on site, it keeps recording, and some systems upload the gap later. Without it, that stretch is not recorded |
| If the recorder fails | Recording stops for every camera on it | Recording stops, unless cameras also record to their own memory cards | There may be no recorder. A failed bridge stops the cameras that depend on it |
| Remote viewing | The maker's app relay, a VPN (a private, encrypted connection into the building network), or a port opened on the router | The same three routes | Sign in to the service from a browser or app |
| What tends to limit it | How many camera plugs it has, which analog formats the recorder accepts, drive space | How many cameras the recorder accepts, how much power its PoE ports can supply, network capacity, drive space | Upload capacity, the retention plan, the supported-camera list |
In between
Hybrids: many systems mix these
Recorders that take both coax and IP
A hybrid recorder has coax plugs for analog cameras and can also record some IP cameras over its network jack, so cameras can be replaced a few at a time. How many of each it takes varies by recorder.
Cameras with their own storage
Many IP cameras can record to a memory card or built-in storage. That can be the main recording, or a backup that fills a gap when the recorder or network drops out.
Cloud-managed systems with local storage
The video is stored on the cameras or a recorder in the building, and the cloud handles sign-in, viewing and sometimes a second copy. Ask where each copy is kept and for how long, because 'cloud' on a quote can mean any of these.
An encoder in front of an NVR or cloud service
An encoder is a small box that takes analog cameras on coax and puts their video on the network as if they were IP cameras.
Cameras and recorders from different makers
Mixing makers usually relies on ONVIF, an open standard for IP security products. Check that the camera and the recorder list the same ONVIF profile, which is a fixed set of features that both support. ONVIF ends support for Profile S on March 31, 2027 and names Profile T as its replacement. ONVIF says Profile S products already installed stay interoperable with each other, but a maker's later firmware can remove the older sign-in method and end that, so ask before updating cameras or a recorder in a mixed-maker system.
Choosing
What decides the choice
Find the row that sounds like your building. A row names what that situation tends to point to; it doesn't say one type is better than another.
| If this sounds like your building | What it usually points to | Why |
|---|---|---|
| Coax is already in the walls, the cameras still give a good picture, and the recorder is the part that is old or full | Often suits keeping the analog cameras on a new DVR, or new analog or IP cameras on the same coax | The cable in the walls can stay. See 'Upgrading without rewiring'. |
| Ceilings are open, the building is being renovated, or network cable already reaches the camera positions | Usually points to IP cameras, recorded on an NVR or by a cloud service | One network cable can carry both power and video. |
| Several sites reviewed by one person | Often suits a cloud system, or recorder software with one sign-in | One sign-in shows every site. |
| Upload capacity is limited, or footage is required to stay in the building | Usually points to a recorder on site, a DVR or an NVR, with a cloud copy if the upload can carry it | Cloud recording uses upload, the direction many business connections have least of. Have it measured at the site. |
| An insurer, lease, IT policy or regulator may set where video is stored, how long it is kept or what may join the network | Ask them before choosing | Any of these can rule an option in or out. |
- Days of footage needed and who views the video (a manager on site, an owner at home, a remote guard service) also shape the choice; see 'Retention and storage in plain words'.
- Who maintains it. A recorder needs someone to notice a failed drive and apply updates. A cloud provider updates its own side, and the cameras and any box on site still need the same care. Ask who is responsible for each.
Storage
Retention and storage in plain words
Retention is how many days back you can play. Storage is the drive space or cloud plan behind it. Four things drive how much you need.
- Picture detail and frame rate: more detail, or more pictures per second, means bigger files
- Compression: some cameras and recorders squeeze video into smaller files than others, and the saving only counts if both the camera and the recorder support the newer method
- Motion or continuous: recording on motion saves space, at the risk of missing an event the camera did not detect
- Days kept, multiplied by the number of cameras
A busy scene takes more space than a quiet one, so two cameras on the same settings fill a drive at different rates. When a recorder's drive is full it normally records over the oldest footage, which is why a system can hold fewer days after cameras are added or settings are raised. Ask the installer to work the storage out from your cameras and settings, and check the oldest recording date once the system has been running.
Upgrades
Upgrading without rewiring
New cable is often a large part of a camera job, so start with what the existing coax can still do.
| Route | What stays | What to check first |
|---|---|---|
| Replace the recorder alone | Cameras, coax and power | Which analog format each camera sends, and that the new recorder reads it |
| New HD analog cameras and recorder | Coax and usually the power wiring | The condition of the coax and connectors, and the longest run |
| IP cameras on the old coax, with an adapter at each end that carries network and power | Coax | The power each camera needs and the run length the adapter supports |
| An encoder feeding an NVR or cloud service | Cameras, coax and power | That the encoder reads the cameras' format and the recorder or service accepts it |
| New network cable | The camera positions | Cable routes, ceiling access, and where the switch and recorder will sit |
Upkeep
Security and upkeep
A recorder or camera is a computer on your network, and all three types need the same basic care.
Change default passwords as soon as possible, and before the system is connected to an untrusted network such as the internet. Give each person their own login, and remove it when they leave.
Keep firmware, the software inside the recorder and cameras, up to date with security patches, and plan to replace devices that no longer receive security support. A cloud provider normally updates its own side. Ask who is responsible for the cameras.
Be careful with remote access. A recorder reached through a port opened on the router is publicly accessible, and internet search tools can find publicly accessible systems. A VPN or a secure gateway lets you reach the recorder without exposing it directly to the internet. The maker's remote service does not need a port opened on your router, but it is only as secure as that service and its sign-in. Turn on a second sign-in step, such as a code sent to a phone, where the system offers it.
Troubleshooting
Common problems and what they usually point to
Count first: one camera, several, or all of them. Read any message on the recorder's screen or in the app before restarting anything, and leave the inside of the recorder and its power supplies to a technician.
| What you see | What it can point to | Where to look first |
|---|---|---|
| One camera shows 'no video' or a black tile | That camera, its power, its cable or a connector. On a DVR, also a format the recorder does not read | Whether the camera's lights are on, and the plug at the recorder end |
| Every camera is out at once | DVR: the shared camera power supply or the recorder. NVR: the PoE switch, the network or the recorder. Cloud: the internet, the switch or the bridge | What the dead cameras share |
| Rolling lines, flicker or a washed-out picture on an analog camera | A damaged cable or connector, electrical interference, or a failing camera power supply | Whether it changes when nearby equipment runs |
| An IP camera drops off and comes back | A marginal cable or connector, a PoE switch near its power limit, or two devices set to the same network address, which makes both unreliable | Whether it drops at night, when infrared lighting raises the camera's power draw |
| Live view works but playback is missing or has gaps | A failed or full drive, a schedule or motion setting, or a wrong clock that files footage under another date | The recorder's storage status and its date and time |
| Remote viewing fails while viewing on site works | The internet connection, a replaced or reset router, or an expired account or password | What changed on the network. The cameras are rarely the first place to look |
| Cloud video is choppy or has gaps | Too little upload capacity, weak Wi-Fi at the camera, or other traffic on the connection | Whether it is worse at busy times of day |
A quicker quote
What to tell the installer
Know the maker? See Axis cameras and recorders, Hanwha Vision recorders or Eagle Eye Networks cloud video for what each maker's documents say.
- Photos of the back of the recorder, its label, and one camera with its cable
- How many cameras you have, how many work, and how many you want
- How many days of footage you need, and whether an insurer, lease or policy sets that
- Your internet upload speed, and whether IT allows cameras on the building network
- Who needs to view video, and from where
- Whether ceilings and walls are open for new cable or finished
Elwin Security installs, repairs and supports camera and recording systems for commercial and multifamily properties in the San Francisco Bay Area; see security camera installation. Calls are answered 8:00 AM-8:00 PM daily at (408) 539-0535.
Common questions
Questions about NVRs, DVRs and cloud video
Is an NVR better than a DVR?
Not by type alone. A DVR records analog cameras over coax and an NVR records IP cameras over a network, so the cameras and cable you have or want decide between them.
Can a DVR record IP cameras, or an NVR record analog ones?
Some can. A hybrid recorder takes analog cameras on coax and some IP cameras over the network. An NVR can record analog cameras through an encoder, if it accepts that encoder.
Can I reuse my coax cable for IP cameras?
Often, yes. An adapter at each end of a coax run can carry network data and power to an IP camera. Whether it works in your building depends on the condition and length of the coax and the power the camera needs.
Do I need the internet for a DVR or NVR?
Not to record. A DVR or NVR normally records to its own drives with no internet. The internet is needed for viewing from off site, phone alerts and any cloud copy.
Sources and further reading
These sources back up the general guidance. Your building and the people who approve the work decide the details for your doors.