diff --git a/README b/README
index ef76871..67265c0 100644
--- a/README
+++ b/README
@@ -521,9 +521,12 @@ or dynamically through the udev system.
 
 * /dev/dahdi/ctl (196:0) - a general device file for various information and
   control operations on the DAHDI channels.
+* /dev/dahdi/channels/N/M - A device file for channel M in span N
+  (M is chanpos - numbering relative to the current span).
 * /dev/dahdi/NNN (196:NNN) - for NNN in the range 1-249. A device file for
   DAHDI channel NNN. It can be used to read data from the channel
-  and write data to the channel.
+  and write data to the channel. It is not generated by default but may
+  be generated as a symlink using udev rules.
 * /dev/dahdi/transcode (196:250) - Used to connect to a DAHDI transcoding
   device.
 * /dev/dahdi/timer (196:253) - Allows setting timers. Used anywhere?
@@ -851,6 +854,60 @@ A very short type string.
 Current sync source.
 
 
+Channels Bus
+^^^^^^^^^^^^
+Each DAHDI channel is represented by a node under
+/sys/bus/dahdi_channels/devices with the name 'dahdi!channels!N!M'
+(where N is the number of the span and M is the number of the channel
+in the span - chanpos). Channels of each span also reside under the node
+of the span.
+
+Useful attributes in the channel node (All attributed listed below are
+read-only):
+
+===== /sys/bus/dahdi_spans/devices/span-N/dahdi!channels!N!M/alarms
+List of names of the current active alarms (space separated). Normally
+(no alarms) empty. Example:
+
+  RED YELLOW
+
+===== /sys/bus/dahdi_spans/devices/span-N/dahdi!channels!N!M/blocksize
+The block size set by userspace.
+
+===== /sys/bus/dahdi_spans/devices/span-N/dahdi!channels!N!M/channo
+The (global) channel number.
+
+===== /sys/bus/dahdi_spans/devices/span-N/dahdi!channels!N!M/chanpos
+The channel number within the span.
+
+===== /sys/bus/dahdi_spans/devices/span-N/dahdi!channels!N!M/dev
+Major and minor device numbers.
+
+===== /sys/bus/dahdi_spans/devices/span-N/dahdi!channels!N!M/ec_factory
+The name of the echo canceller to be used in the channel, if one is
+configured. Example:
+
+  MG2
+
+===== /sys/bus/dahdi_spans/devices/span-N/dahdi!channels!N!M/ec_state
+State of the echo canceller. ACTIVE: configured and inuse. INACTIVE
+otherwise.
+
+===== /sys/bus/dahdi_spans/devices/span-N/dahdi!channels!N!M/in_use
+1 if the channel is in use (was opepend by userspace), 0 otherwise.
+
+===== /sys/bus/dahdi_spans/devices/span-N/dahdi!channels!N!M/name
+A name string for the channel
+
+===== /sys/bus/dahdi_spans/devices/span-N/dahdi!channels!N!M/sig
+The signalling types set for the channel. A space-separated list of
+signalling types.
+
+===== /sys/bus/dahdi_spans/devices/span-N/dahdi!channels!N!M/sigcap
+The signalling types this channel may be configured to handle. A space-
+separated list of signalling types.
+
+
 User-space Interface
 ~~~~~~~~~~~~~~~~~~~~
 User-space programs can only work with DAHDI channels. The basic