13-Aug-2018, 20:14
(This post was last modified: 13-Aug-2018, 20:21 by ada.
Edit Reason: url typos
)
As I wrote above, I started to do some research and with using wireshark (it is a package sniffing tool) I started to compare the UPnP and Devialet AIR and Roon Air.
First of all, I am now sure that UPnP via Audirvana is superior than any kind of AIR implementation (doesn't matter if it is from Roon or Devialet) because of one certain reason. UPnP streaming traffic (UPnP commands are not important as we only stream the sound not the commands) in Audirvana goes through TCP [1] and there is always a package integrity mechanism in place. This means every package that is sent by Audirvana has a response from Devialet and if somehow the package is lost or in wrong order or is corrupted, it will be fixed in process.
On the other side both Devialet and Roon AIR integrations are fully working on UDP [2] protocol. This means there is no handshaking, no guarantee of delivery, order or duplicated packages.
I have been working in OTT (video streaming) sector as an engineer and senior management profile for a long time, I know both protocols very well, we also use both of them in certain cases. For example for live traffic, you want a lower latency and much more real time stream and you don't care if you lose quality or have glitches in the traffic because that is fine as people are focused on the live content but on the other side if you provide premium VOD service, you will want to be sure the customer has the best quality and best possible user experience to compete with Netflix or any other vendor and to reach to the quality of the powerful HDR supported devices. And for case 1 UDP is the ideal protocol but for the case 2 TCP is one of the best ways to go.
Of course, I am not an expert of Roon, Devialet or Audirvana, they should know better than me but by today no power can force me to use Devialet or Roon AIR as it is sick by the fundamental to be bit perfect of any kind of perfect or even anything good. If you are OK to stream content from Spotify (lossy) and if you don't care the reliable network (means you use a cheap router) and if you use your mobile phone as the player (you don't have any Roon, Audirvana or any special hardware as the player) than I will completely say AIR doesn't have any issue at all. But! If you pay couple of hundreds or thousands of euro for your streamer, network adapter, content subscription and player software, you would be aware of this UDP vs TCP problem we are talking here.
I can't understand how Devialet sold this AIR idea as bit-perfect maybe in the past they tried to use TCP but they couldn't handle it and removed, I don't know.
I know that I left some strong opinions in this comment and those can be a direct blame to RoonLabs or Devialet, I am totally open to hear from them and if they fix anything that I am saying here, I will ensure you, I will modify my comment and apologise for the parts that I mislead you here.
Side topic: I was investigating what can be the root cause of the instability of the UPnP between Audirvana and Devialet and I found out that there are some 401 messages [3] comes from Devialet to Audirvana for some certain commands. This may mean Devialet doesn't have fully support for all the UPnP commands or Audirvana doesn't have a proper integration. There is no simple way to be sure which one is doing something wrong. (I can read the full UPnP Architecture documentation and find out the real root cause but I don't have this much time for now) But all in all seems like there is still room to improve the UPnP integration on at least one of the sides.
[1] TCP provides reliable, ordered, and error-checked delivery of a stream of octets (bytes) between applications running on hosts communicating via an IP network. Ref: https://en.wikipedia.org/wiki/Transmissi...l_Protocol
[2] It has no handshaking dialogues, and thus exposes the user's program to any unreliability of the underlying network; There is no guarantee of delivery, ordering, or duplicate protection. If error-correction facilities are needed at the network interface level, an application may use Transmission Control Protocol (TCP) or Stream Control Transmission Protocol (SCTP) which are designed for this purpose. Ref: https://en.wikipedia.org/wiki/User_Datagram_Protocol
[3]HTTP 401. Ref: https://developer.mozilla.org/en-US/docs...Status/401
First of all, I am now sure that UPnP via Audirvana is superior than any kind of AIR implementation (doesn't matter if it is from Roon or Devialet) because of one certain reason. UPnP streaming traffic (UPnP commands are not important as we only stream the sound not the commands) in Audirvana goes through TCP [1] and there is always a package integrity mechanism in place. This means every package that is sent by Audirvana has a response from Devialet and if somehow the package is lost or in wrong order or is corrupted, it will be fixed in process.
On the other side both Devialet and Roon AIR integrations are fully working on UDP [2] protocol. This means there is no handshaking, no guarantee of delivery, order or duplicated packages.
I have been working in OTT (video streaming) sector as an engineer and senior management profile for a long time, I know both protocols very well, we also use both of them in certain cases. For example for live traffic, you want a lower latency and much more real time stream and you don't care if you lose quality or have glitches in the traffic because that is fine as people are focused on the live content but on the other side if you provide premium VOD service, you will want to be sure the customer has the best quality and best possible user experience to compete with Netflix or any other vendor and to reach to the quality of the powerful HDR supported devices. And for case 1 UDP is the ideal protocol but for the case 2 TCP is one of the best ways to go.
Of course, I am not an expert of Roon, Devialet or Audirvana, they should know better than me but by today no power can force me to use Devialet or Roon AIR as it is sick by the fundamental to be bit perfect of any kind of perfect or even anything good. If you are OK to stream content from Spotify (lossy) and if you don't care the reliable network (means you use a cheap router) and if you use your mobile phone as the player (you don't have any Roon, Audirvana or any special hardware as the player) than I will completely say AIR doesn't have any issue at all. But! If you pay couple of hundreds or thousands of euro for your streamer, network adapter, content subscription and player software, you would be aware of this UDP vs TCP problem we are talking here.
I can't understand how Devialet sold this AIR idea as bit-perfect maybe in the past they tried to use TCP but they couldn't handle it and removed, I don't know.
I know that I left some strong opinions in this comment and those can be a direct blame to RoonLabs or Devialet, I am totally open to hear from them and if they fix anything that I am saying here, I will ensure you, I will modify my comment and apologise for the parts that I mislead you here.
Side topic: I was investigating what can be the root cause of the instability of the UPnP between Audirvana and Devialet and I found out that there are some 401 messages [3] comes from Devialet to Audirvana for some certain commands. This may mean Devialet doesn't have fully support for all the UPnP commands or Audirvana doesn't have a proper integration. There is no simple way to be sure which one is doing something wrong. (I can read the full UPnP Architecture documentation and find out the real root cause but I don't have this much time for now) But all in all seems like there is still room to improve the UPnP integration on at least one of the sides.
[1] TCP provides reliable, ordered, and error-checked delivery of a stream of octets (bytes) between applications running on hosts communicating via an IP network. Ref: https://en.wikipedia.org/wiki/Transmissi...l_Protocol
[2] It has no handshaking dialogues, and thus exposes the user's program to any unreliability of the underlying network; There is no guarantee of delivery, ordering, or duplicate protection. If error-correction facilities are needed at the network interface level, an application may use Transmission Control Protocol (TCP) or Stream Control Transmission Protocol (SCTP) which are designed for this purpose. Ref: https://en.wikipedia.org/wiki/User_Datagram_Protocol
[3]HTTP 401. Ref: https://developer.mozilla.org/en-US/docs...Status/401
