RTP midi

RTP midi

Postby redrum » 08 Nov 2011, 16:50


What is the difference with RTP-midi?
Posts: 7
Joined: 08 Nov 2011, 15:41

Re: RTP midi

Postby Copperhead » 22 Dec 2011, 00:28

Well! There are many differences between CopperLan and RTP-MIDI.

RTP-MIDI is a guideline to transport standard MIDI over UDP or TCP.
CopperLan is a complete framework comprising a network transport definition, a high-level protocol (which happens to cover MIDI capability), drivers, virtual network implementations (to serve multiple applications at each physical connection), and a set of APIs ready to talk with application code.

There are so many differences to mention that I could cover only a few.

System integration
While the CopperLan protocol is the master of its own transport, this is not the case for MIDI. MIDI is not able to control its own container. A lesser protocol cannot control a higher topology it does not understand.
It means that the whereabouts of connecting the equipment is part of the networking domain (RTP/UDP/TCP) while the performance (payload) is defined in another domain (MIDI), both domain having no control relation.

Data resolution
RTP-MIDI only does MIDI resolution. In CopperLan, the minimum resolution is 16-bit. with higher resolution up to 128 bit being also part of the specification according to IEEE/ANSI 754.

Merging and remapping
RTP-MIDI is using the network to establish sets of A to B virtual MIDI cable, each carrying their content "as is".
On the other hand, when CopperLan is used to carry messages from MIDI sources, it allows directing any MIDI channel from any source to any destination, on a channel basis, and this by also defining under which channel identity the data will be delivered. This means free channel remapping and unlimited merging, all done transparently by the fact of establishing connections.

Target identification
With RTP-MIDI the addressing system is IP-based. IP addresses should be allocated to each target so that sources can be linked to them. By the way, for such system to work there should be one DHCP (and one only) server in the setup. This might be annoying for some uses since this DHCP server should be located into whatever equipment is available in the setup (maybe only stage equipment and no computer)
In RTP-MIDI, a piece of equipment does not have any permanent network identity it can carry away into another setup without being assigned a new identity. Moreover such identity is purely abstract.
In CopperLan, every piece of equipment carries its unique identity without any need for setting-up.
The whole CopperLan network being zero-config plug-&-play, it suffices to connect any two pieces of equipment to establish a network. There is no need for a DHCP server since CopperLan is not IP based.

Delivery and network management
The RTP-MIDI document RFC6295 says that "RTP itself does not provide service guarantees." then adding that it is up to the applications to care for such aspects.
The delivery guarantee and network management aspects are completely integrated into CopperLan by design. Just a few examples: Global system time, automatic flow-control, multi-format time stamping, auto-discovery of equipment addition and losses, auto reconnect after failure or cable disconnect, etc

We could go further if you have specific questions.
User avatar
Site Admin
Posts: 70
Joined: 16 Apr 2011, 11:43
Location: Belgium

Return to Questions