Nortel Meridian 1 Option 11C Planning And Installation Manual page 326

Page 326 of 408 Pre-programmed data
553-3021-210 Standard 7.00
Enhanced Serial Data Interface (ESDI) port
Port 9 is pre-programmed as an ESDI port and supports Meridian Mail. It
functions as a Command Status Link with the settings given in Table 80:
January 2002