[asterisk-ss7] chan_dahdi.c: Write returned -1

[peterpet]

Hello,
does anyone know what is mean this error?

  DEBUG[10757] chan_dahdi.c: Write returned -1 (Resource temporarily 
unavailable) on channel 87
  DEBUG[10757] chan_dahdi.c: Write returned -1 (Resource temporarily 
unavailable) on channel 87
  DEBUG[10757] chan_dahdi.c: Write returned -1 (Resource temporarily 
unavailable) on channel 87
  DEBUG[10757] chan_dahdi.c: Write returned -1 (Resource temporarily 
unavailable) on channel 87
  DEBUG[10737] chan_dahdi.c: Write returned -1 (Resource temporarily 
unavailable) on channel 130
  DEBUG[10737] chan_dahdi.c: Write returned -1 (Resource temporarily 
unavailable) on channel 130
  DEBUG[10737] chan_dahdi.c: Write returned -1 (Resource temporarily 
unavailable) on channel 130
  DEBUG[10737] chan_dahdi.c: Write returned -1 (Resource temporarily 
unavailable) on channel 130
  DEBUG[10737] chan_dahdi.c: Write returned -1 (Resource temporarily 
unavailable) on channel 130
  DEBUG[10757] chan_dahdi.c: Write returned -1 (Resource temporarily 
unavailable) on channel 87

Regards,
Peter Petrov