DTO - Dial Tone Office

Identifies the WATS serving office in CLLI Code (Common Language Location Identifier) An 11-digit code that an ILEC assigns to acarrier’s location to designate the Central Office or area served by a Central Office.Characters 5 and 6 are the state code, 7 and 8 are the Central Office name, and 9through 11 specify equipment type. CLLI is a trademark of Telcordia. format.

NOTE 1: The format and structure of this field is defined in the ANSI approved standard, ATIS-0300253, Identification of Location Entities for Information Exchange. The CLLI Code consists of the following elements:

1. Geographical Code - Positions 1 through 4 describe the designation for a single geographical locality within a state, province, territory, country, or distinct region of the world (e.g., municipality) (4 alpha characters).

2. Geopolitical Code - Positions 5 and 6 describe the designation of a state or territory of the United States, a province or territory of Canada, another country having a national federal government, or a unique designation (2 alpha characters).

3. Network Site Code - Positions 7 and 8 describe the designation of a site of an existing or proposed structure within a geographical location where there is a need to identify one or more telecommunications equipment entities, facility terminations, nodal locations, or administrative operations (2 alpha or 2 numeric characters).

4. Network Entity Code - Positions 9 through 11 describe the functional category of equipment or work center that is contained in a structure. Equipment categories, including central office ILEC's primary point to connect customers to the network. These highly secure buildingscontain computerized network switching equipment. switching and ancillary equipment or non-switching or access terminations, are associated with a building or network site for purposes of maintaining equipment inventories and for identifying facility and circuit terminations and nodal locations  (3 alpha/numeric characters).

NOTE 2: Valid CLLI Codes are outlined in Telcordia Technologies practice BR 795-(100-186)-100.

NOTE 3: The provider may provide WATS serving office CLLI Codes and the criteria for selection.

NOTE 4: The customer may indicate the WATS dial tone office (DTO) preferred on new and outside move requests.

NOTE 5: The provider will make every reasonable effort to honor this preference; however, the provider will make the final determination of the serving office.

USAGE: This field is conditional.

NOTE 1: Optional when the ACT field on the ASR Access Service Request Form is “N” or “T”, otherwise prohibited.

DATA CHARACTERISTICS: 11 alpha/numeric characters

EXAMPLE: M I L N T N M A 6 3 6