What is the difference between DLNA and UPNP?

Question

Can someone tell me the what is the difference between DLNA and UPNP? I can see that some device (such as NASes) specifications mention both (e.g., Iomega StorCenter) or only DLNA (e.g., Netgear Stora).

Are these synonyms for the same thing or are there actually two different protocols? Are they compatible, e.g., if a media server uses DLNA and the streaming device uses UPNP, will it work?

Answer 1

UPnP and DLNA are two different standards.

DLNA is derived from UPnP, as an attempt to normalize media interoperability. It does this partly by being more restrictive than UPnP (e.g. by restricting the number of media formats) and partly by adding features (like DRM, i.e. copy protection).

DLNA guidelines can be thought of as an umbrella standard that defines how the home network interoperates at all levels.

From the DLNA whitepaper (pdf).

The UPnP A/V spec provided a strong and flexible means to share content throughout the home, but because UPnP offered rather overwhelming flexibility in the choices vendors and providers could make in configuring their products and services, (push vs. pull, what types of video and audio file formats have to be supported, etc.) the DLNA developed its own interoperability guidelines to simplify the process.

From http://www.broadband2.com/usingstandardstostandout.asp

I couldn't find a clear answer on whether pure UPnP and pure DLNA devices are directly interoperable today, but in 2006 they weren't (pdf). My bet would be "probably not", unless at least one of the devices can handle both.

Answer 2

A UPnP device can stream from a DLNA server just fine.

A DLNA device MAY be able to stream from a UPnP server. Since DLNA is effectively a subset of UPnP, it's possible the UPnP server may offer a format that your DLNA device doesn't recognize and/or support.

But in practice, they're roughly synonymous.

Answer 3

From Wikipedia: DLNA

DLNA uses Universal Plug and Play (UPnP) for media management, discovery and control.[4] UPnP defines the types of device that DLNA supports ("server", "renderer", "controller") and the mechanisms for accessing media over a network. The DLNA guidelines then apply a layer of restrictions over the types of media file format, encodings and resolutions that a device must support.

From Wikipedia: UPnP

Universal Plug and Play (UPnP) is a set of networking protocols that permits networked devices, such as personal computers, printers, Internet gateways, Wi-Fi access points and mobile devices to seamlessly discover each other's presence on the network and establish functional network services for data sharing, communications, and entertainment. UPnP is intended primarily for residential networks without enterprise class devices.

Answer 4

As far as I understand from these posts (1;2), DLNA is a subset and restricted form of the UPnP standard and specifies less options and more strict formats. Most probably you won't be able to access a media server using DLNA from a streaming device using UPnP. Hope that helps.

Answer 5

DLNA is a standard that uses UPnP as its foundation. DLNA and UPnP devices can work together. For example, I frequently play digital audio from a DLNA/UPnP Media Server to a UPnP only Media Renderer. UPnP provides all the basic control functions: play, pause, skip, previous, set repeat mode (NORMAL, REPEAT_ONE, SHUFFLE, REPEAT_ALL), set and get volume, and more.

DLNA focuses: 1. improved compatibility between DLNA devices 2. Security and Digital Rights Management 3. Media Devices 4. Better specification of media files (codecs, encryption, bit rate, etc.) 5. A few extensions. More actions like seek to specified byte position. More state variables that report the device state.

UPnP is an old standard that has been loosely interpreted by some manufacturers so there can be compatibility problem between UPnP devices.

I find that DLNA Media Controllers sometimes don't work well with pure UPnP Media Renderers. BubbleUPNP on Android works well with a pure UPnP Media Renderer. I could not find many pure UPnP Media Controllers. Most now support DLNA and UPnP.

The dozen DLNA Media Servers I have tested work well with a pure UPnP Media Renderer.

I can play music from Windows Media Library using a DLNA Media Controller to a pure UPnP Media Renderer, but I can't go to Windows Media Player and tell it to play to the UPnP Media Renderer. I think Windows Media Player can only control DLNA Media Renderers.

Answer 6

DLNA is based on UPNP A/V.

UPNP A/V ended up being an interoperability nightmare. The UPNP A/V standard is very open ended. Many features are optional. There is no baseline set of media formats that devices have to support. Video format support is a problem for pretty much all media devices. At the time that UPNP A/V was released, this was particularly true in a time when Apple and Microsoft were actively warring on "standard" media formats, and few vendors were willing to adopt open formats such as FLAC, and MKV whose patent and licensing status was up in the air at the time, or to pony up for an endless laundry list of patent portfolio licenses required to play standardized formats.

In addition, the UPNP A/V standards were very loosely specified. Utterly extraordinary readings of the standard were common. Minimalist implementations were the rule rather than the exception. And the pursuit of minimalism lead to some pretty extraordinary readings of the UPNP A/V standard.

DLNA was an attempt to fix the shortcomings of UPNP A/V by heaping thousands of pages of additional requirements on top of the UPNP A/V standards. The DLNA standards organization provided standardized tests suites that certified devices had to pass.

According to the DLNA specs, DLNA devices SHOULD be compatible with UPNP A/V devices, according to the terms of the DLNA standard. But there is no requirement that they MUST be compatible. So (surprise surprise) more often than not, they are not compatible. In fairness, some common UPNP implementations were so jaw-droppingly bad that this is not entirely the fault of the DLNA consortium.

DLNA also had its problems. It originally cost somewhere in the neighborhood of $50,000 to get a set of the specs, and (tens of?) thousands of dollars to get the certification, and frankly, plus an additional requirement in practice to acquire a bottomless pit of ISO standards documents in the ISO MPEG family of standards at enormous expense, since these standards were incorporated by reference in the DLNA standards, which then in turn incorporate by reference other ISO standards. All at huge expense. All of which in turn precluded any sensible open-source DLNA implementation.

UPNP A/V on the other hand, had been published in freely available documents.

Plus the sheer size of the DLNA specifications, which still had all kinds of CANs and MUSTs and SHOULDs liberally scattered through the requirements. Making it painfully easy for two certified DLNA devices to want to have nothing to do with each other because of incompatible CANs and SHOULDs.

So when it was all said and done, alhtough interoperability had improved dramatically, it still wasn't that great.

Most of the time these days, UPNP devices mostly interoperate with DLNA devices but aren't certified (because of the prohibitive cost of doing so) so they can't be called DLNA devices.