This read-only gauge reports the current length, in cells, of the egress queue for this channel. An admin monitors this as a real-time indicator of outbound congestion specific to this virtual channel, useful for correlating with egress discard counters to confirm whether buffer buildup is actually occurring. For example, if this egress queue depth stays consistently high while discard counters also climb, the admin has direct evidence this channel's outbound path, not some other part of the switch, is the source of congestion.