Network Traffic Between Halogen and HAL
A variety of network traffic flows between a HAL device and a PC running the Halogen software. This traffic can be non-exclusive (in other words, between multiple HAL devices and multiple PCs running ) or exclusive (between a single HAL connected to a single PC running Halogen).
note: Because RaneLink is a Windows service, it runs in the background on the PC—receiving messages from HAL devices even when Halogen is not running.
- As part of its discovery protocol, the HAL device sends a UDP broadcast announcement (less than 100 bytes in size) to address 255.255.255.255 every three seconds. The RaneLink service listens for these announcements on UDP port 4994. HAL also sends system status updates to RaneLink on TCP port 4994. These status messages are less than 256 bytes in size and are only sent when major events occur (for example, resolution of a device mismatch or completion of a host firmware update).
- When a PC that is running Halogen is connected to a HAL, various messages are sent to and from TCP port 4993 as the user drives the software or manipulates the live hardware. These messages keep the HAL and Halogen software in sync with one another. The size of these individual messages can vary greatly but should never exceed one megabyte.
- When connected to a HAL, Halogen is able to display live audio meter data. When Halogen is displaying one or more live meters, HAL sends a message to TCP port 4995 on the PC every 20 milliseconds. The amount of meter data streaming from the HAL should not exceed 0.2 megabits per second regardless of how many meters are displayed.
note: The number of active meters is limited to 16, regardless of how many are currently displayed in Halogen.
Whenever Halogen changes which meters are active in the Halogen property dialog boxes (which can happen when the user opens or closes a dialog, activates a room, or brings a dialog window into focus), HAL and the PC exchange the meter control data on TCP port 4992. These meter control messages are no more than 200 bytes in size.
- Halogen uses ssh and sftp to transfer data in bulk to and from the HAL on which it is working. The sftp server on the HAL uses TCP port 22. The amount of data transferred depends on the size of the configuration file or host firmware update. This ssh and sftp traffic typically occurs only during setup or maintenance of the HAL.