osmo-e1d¶

The envisioned osmo-e1d is a daemon that handles Osmocom E1 interfaces. Its main tasks are:

1. communicate with each E1 line hardware interface via USB USB_Protocol (or UDP/IP)
2. provide a per-timeslot interface towards the users (such as OsmoBSC and OsmoMGW
   • likely unix domain socket based, so libosmo-abis and friends can keep their "one FD per
3. provide some kind of interface by which the user application can
   • perform line/interface based operations
     • enumerate the list of available interfaces/lines
     • obtain status information (LOS, Alarm, CRC4 errors, etc) on each line
   • timeslot based
     • claim/release individual timeslots
     • enable/disable Rx/Tx of individual timeslots (could be implicit in claim?)
     • switch individual timeslots between raw and HDLC/CRC mode
     • obtain timeslot status information such as CRC16 errors, frame errors, ...
4. implement any internal handling required, such as
   • perform tasks not implemented by the adapter hardware/firmware (CRC4 tx / rx, multiframe alignment, LOS / ALRM / state machines)
   • implement HDLC on each requested timeslot

User point of view¶

A user application would be interested in performing the following operations:

• obtain a list of lines/interfaces
• obtain a list of timeslots at a given line/interface, including availability status
• select/open a given timeslot on a given line
• enable/disable a given timeslot
• switch mode (raw/hdlc) of a given timeslot
• obtain line status information like local/remote CRC4 / LOS / ALARM
• receive data from a given TS
• transmit data on a given TS