The following guidelines are provided for using the loss groups:

• Use loss groups 1, 2, 3, 4, 5, and 19 for the following types of stations:

  • 1, 4, and 5 for analog stations

  • 2 for digital stations

  • 3 for BRI stations

  • 19 for IP stations

• Use loss groups 6, 7, and 8 for analog central office (CO) trunks. Analog CO trunks must not use other loss groups.

• Use loss groups 12, 13, and 14 for digital tie trunks.

• Use loss groups 9 and 10 for analog tie trunks.

• Use loss group 15 for tie trunks (analog or digital) where the length of the trunks are less than 100 miles. For example, always select the loss group 15 for tie trunks connecting switches on the same campus.

• Use loss group 11 for digital CO trunks.