DLNA

DLNA is a super-set of UPnP.

 

DLNA (Digital Living Network Alliance) is the industry standard making all kind of AV-gear communicates with each other over the home network. It allows you to control one device with another, stream audio or video over the network, etc.
It is a standard with broad support.

DLNA claimed four billion certified devices in 2017

 

In 2017 the Digital Living Network Alliance announced that the organization has fulfilled its mission and will dissolve as a non-profit trade association. Product certification services for the multimillion-unit DLNA ecosystem will continue to be provided through a newly formed professional services firm with all required DLNA test tools, infrastructure equipment and end-to-end certification expertise.

This firm is SpireSpark.

 

OCF (Open Connectivity Foundation) does UPnP certifications.

 

DLNA Certification Program

In order to earn the DLNA Certified logo, the products must pass through the DLNA Certification Program. DLNA member companies also get together regularly in what are called “Plugfests” to test the compatibility of their products against the DLNA guidelines.

Do check if a product is certified.

Older or not certified implementations might give you a lot of problems.

When DLNA stopped as a non-profit organization, certification was taken over by SpireSpark.

DLNA Terminology

1. DMS -- Digital Media Server -- where the media resides

2. DMP -- Digital Media Player -- where the media is played

3. DMR -- Digital Media Renderer -- where media is played, but with ability to respond to a controller

4. DMC -- Digital Media Controller -- software control of the renderer -- functions as a remote

Gapless playback

Although DLNA incorporates UPnP, the standard doesn’t support gapless playback.
UPnP does (the magic word seems to be the SetNextAVTransport).
Even if your hardware supports gapless playback, it will not necessarily be supported by the server software as well and visa versa.
Always check if gapless is supported. Nothing as annoying as a white space in a live concert.