ipMIDI - FAQ
Frequently Asked Questions
Q: Now, I know the “U” in UDP means ‘unreliable”. Doesn’t this mean I could lose data/miss beats?
A: A local network is usually as stable as a rock and you won't lose even one packet. You can easily test this with the ping comand. In a command window (Start -> Run -> cmd) type:
ping -n 10 -l 3 <ipOfSecondComputer>
(this example sends 10 messages with the size of 3 bytes, the size of a common midi message, to a second computer and back again)
The result should be something like:
ping -n 10 -l 3 192.168.0.100
Reply from 192.168.0.100: bytes=3 time<1ms TTL=128
Ping statistics for 192.168.0.100:
Packets: Sent = 10, Received = 10, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 3ms, Average = 0ms
which indicates no lost data and an average latency near zero.
Q: Can my ipMIDI network co-exist with my normal TCP/IP data network, and can I run other network-oriented applications (like an HTTP webserver) at the same time?
A: Yes, in a common studio environment people are connected to the Internet via cable or DSL, which takes only 1% of your network capacity.
Q: I want to jam with my friends remotely: will ipMIDI permit that?
A: No, ipMIDI does not transfer data over the Internet. An TCP/ip add-on is planned, then it will be possible for example to sync two sequencers over the Internet. However, jamming together will only be possible with a delay, because there is no internet real-time solution (even with the so-called "real-time protocols") to inherent latency.
Q: Can I use a Wireless network?
A: Yes, The following three prerequisite must be fulfilled:
- You should be in the same room—remember, any packet loss also means MIDI data loss! To ensure a good connection position your computers for the best signal strength (for example, try to avoid a wall between the computers). If you cannot avoid a separating wall or if you doubt the validity of the connection, try the above test.
- Update to the latest wlan network card driver and/or access point firmware. Do it! Especially the first Generation of Centrino™ based Notebooks were not fully multicast capable.
- Disable PSP (Power Save Polling) and set the adapter to CAM (continually aware mode). In a mobile environment, power save polling mode is a feature for extended battery life for mobile stations. ipMIDI (and other real-time streaming apps) will extremely jitter with PSP. ipMIDI comes with a step by step description how to disable PSP and how to setup a wireless connection.
Q: How do I uninstall ipMIDI for Apple Mac OS X?
A: To uninstall ipMIDI simply delete:
Q: I have two network interfaces. ipMIDI is using the wrong one!
A: Network traffic is controlled by the so called "Network routing table". ipMIDI uses the default route like every other application (e.g. Web Browser). To change this behavior, add a routing table entry for ipMIDI's multicast adress 18.104.22.168. This is done in a command window:
route ADD 22.214.171.124 MASK 255.255.255.0 <static_ip_of_wanted_(W)Lan_card>
route -n add -net 225.0.0 -interface <name_of_your_network_interface>
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