Someone

asterisk*CLI> zap restart
 Destroying channels and reloading zaptel configuration.
  == Parsing '/etc/asterisk/zapata.conf': Found
    -- Registered channel 1, ISDN PRI signalling
    -- Registered channel 2, ISDN PRI signalling
    -- Registered channel 3, ISDN PRI signalling
    -- Registered channel 4, ISDN PRI signalling
    -- Registered channel 5, ISDN PRI signalling
    -- Registered channel 6, ISDN PRI signalling
    -- Registered channel 7, ISDN PRI signalling
    -- Registered channel 8, ISDN PRI signalling
    -- Registered channel 9, ISDN PRI signalling
    -- Registered channel 10, ISDN PRI signalling
    -- Registered channel 11, ISDN PRI signalling
    -- Registered channel 12, ISDN PRI signalling
    -- Registered channel 13, ISDN PRI signalling
    -- Registered channel 14, ISDN PRI signalling
    -- Registered channel 15, ISDN PRI signalling
    -- Registered channel 16, ISDN PRI signalling
    -- Registered channel 17, ISDN PRI signalling
    -- Registered channel 18, ISDN PRI signalling
    -- Registered channel 19, ISDN PRI signalling
    -- Registered channel 20, ISDN PRI signalling
    -- Registered channel 21, ISDN PRI signalling
    -- Registered channel 22, ISDN PRI signalling
    -- Registered channel 23, ISDN PRI signalling
    -- Automatically generated pseudo channel
  == Parsing '/etc/asterisk/users.conf': Found
[Apr  1 07:50:39] ERROR[3294]: chan_zap.c:9415 start_pri: Unable to open D-channel 24 (Device or resource busy)
[Apr  1 07:50:39] ERROR[3294]: chan_zap.c:11327 setup_zap: Unable to start D-channel on span 1
[Apr  1 07:50:39] WARNING[3294]: chan_zap.c:9824 zap_restart: Reload channels from zap config failed!