Circuit ID

A circuit ID is a company-specific identifier assigned to a data or voice network between two locations, usually local telephone exchanges. The circuit then, is then leased to a customer or enduser by that ID. A subscriber having an issue with a circuit contacts the Controlling Local Exchange Carrier (Controlling LEC) telecommunications provider to provide this circuit ID for action on the designated circuit.

Telecom Circuit ID formats

The LEC circuit ID's are based on Telcordia Technologies' Common Language Coding. At one time, the abbreviations were meaningful (for example, HC for hi - capacity) but the complexity of the business no longer allows for it.

Carrier Facility format: AAAAA/BBBBBB/CCCCCCCCCCC/DDDDDDDDDDD

• A Prefix: 3-5 Alphanumeric characters. Required.
• B Facility Type: 2–6 Alphanumeric characters. Required.
• C A CLLI Code: 8 or 11 alphanumeric characters. This is a Required Field.
• D Z CLLI Code: 8 or 11 alphanumeric characters. This is a Required Field.

Example:

• HN101/T3U/MPLSMNDT000/GLVYMNORIII is an unframed T3 circuit between two locations in Minnesota.

Serial Number format: AA/BBCC/DDDDDD/EEE/FF/G prefix/service code - service code modifier/serial number/suffix/company identifier/segment name

• A Prefix: 1–2 alphanumeric characters. Optional. They may or may not be based on LATA
• B Service Code: 2 Characters. Required. The type of service this circuit is providing.
• C Service Code Modifier: 2 Characters. Required. Modifies the service code, often used for different billing options.
• D Serial Number: 1–6 digits. Required.
• E Suffix: 3 character suffix to the serial number. May be required, but rarely used.
• F Company Code: 2–4 alphabetic characters (NW, MS, PN, GTEW, NRLD, UDMN, FROT) Required, identifies the Controlling LEC.
• G Segment: 1–3 alphanumeric characters. Optional for point to point, but usually found with multi-point DS0 circuits.

Example:

• 32/HFGS/012345/NW is a T3 Circuit by Qwest
• 73/HCGS/123456/000/NE is a T1 Circuit by New England Telephone
• 44/AQDU/987654/000/G4 is a HDSL Circuit by G4 Telecom

Telephone Number Format: AA/BBBB/CCC/DDD/EEEE/FF/G

• A Prefix: Alphanumeric characters. Required if it exists.
• B Service Code & Modifier: 2–4 alphabetic characters. Required for non-DSL numbered circuits.
• C NPA: 3 digits. This is a required field.
• D NXX: 3 digits. This is a required field.
• E Line: 4 digits. This is a required field.
• ? Extension: 1–5 alphanumeric characters. This is an optional field.
• F For states: AZ, CO, ID, MT, NM, UT, WY, alphas not accepted; convert D1 to 0001, D2 to 0002, etc.
• G Segment: 1–3 alphanumeric characters. This is an rarely used optional field.