CLLI code

CLLI code (sometimes referred to as COMMON LANGUAGE Location Identifier Code and often pronounced as silly) is a Common Language Information Services identifier used within the North American telecommunications industry to specify the location and function of telecommunications equipment or of a relevant location such as an international border or a supporting equipment location, like a manhole or pole.[1] Originally, they were used by Bell Telephone companies, but since all other telecommunications carriers needed to interconnect with the dominant Bell companies, CLLI code adoption eventually became universal. CLLI codes are now maintained and issued by Telcordia, which claims trademarks on the names "Common Language" and "CLLI".[1]

CLLI codes are useful to telecommunications companies for ordering phone service, for the rating of call detail records for billing purposes, and to assist in tracing calls. CLLI codes are associated with Vertical and Horizontal coordinates (frequently abbreviated to "V and H coordinates"), which were developed by AT&T researcher Jay K. Donald to provide a relatively simple method of calculating distance between two network locations.[2] Various mileage-sensitive services are priced according to the V and H coordinates associated with the two endpoints' CLLI codes.[2][3]

Structure

The first six characters of a CLLI code represent the place the code refers to and contain two code elements:

For the various code formats, the remaining two or five characters contain one of:

There are four CLLI code formats.

Network Site Code Format

A Network Site code represents any existing or proposed building, structure, or enclosure, where there is a need to uniquely identify one or more network functions. Network Site codes are typically used to identify building locations, such as central office buildings.

Network Entity Code Format

CLLI codes in the Network Entity format are the most commonly used CLLI codes. Network Entity codes are eleven-character codes used to describe the location and function of network equipment.

Network Support Site Code Format

A Network Support Site code represents any non-building structures or outside plant equipment such as Wireless Access Points, International Boundary Crossing Points, End-Points, Fiber Nodes, Junctions, Manholes, Poles, Base Transceiver Station / Radio Equipment and Repeaters.

This format contains 6 characters representing location and a 5-character Network Support Site Code element.

The code for a communications satellite is STLT (satellite) EO (earth orbit) Q (radio location) then a four-digit identifier.[6]

Customer Site Code

A Customer Site code is used to uniquely identify customer locations. These locations are required to identify customers, circuit terminations, facilities, or equipment for each specific customer for facility provisioning or other requirements. This format contains 6 characters representing location and a 5-character Customer Site Code element.

Entities within client-owned buildings (such as Centrex installations) are coded in the same format as telephone company buildings.

Examples

HSTNTXMOCG0

This code shows two characteristics:

PTLDOR12DS0

Some telephone companies named their central offices, but did not reflect this name in the CLLI code, as in the above example with a numeric location code.

PTLEORTEDS0

The item to note in the above example is that Portland is usually abbreviated as "PTLD", but because of the relatively small number of possible combinations available in the two-character location code, the city abbreviation must occasionally be modified for locations added later, usually by incrementing the fourth character in the code.

DLLSTXRNDS1

Note that this location is actually in Richardson, Texas, not Dallas.[12] Apparently, the organizational structure of Southwestern Bell Telephone at the time considered Richardson to be within its own Dallas organization, although the cities themselves have always been legally separate.

SWASONXTSG1

NorthernTel's +1-705-642 exchange at 5 Cameron Avenue, Swastika was a throwback to a simpler era in which mechanical stepping switches rotated in response to dial pulses from rotary dial telephones. As a step-by-step exchange offers none of the calling features of an electronic or digital switch, these are becoming increasingly rare as mechanical switching equipment is displaced by electronics. This one held out a little longer than most as it was a small community in formerly independent telco territory, but was ultimately replaced by a digital remote station SWASONXTRSA controlled from Timmins TMNSONXTCG0.[14]

OTWAON080MD

Rogers is not a landline incumbent but a rival mobile telephone carrier with a block of 220000 Ottawa numbers. The Iona Street office (OTWAON08) is a co-location facility which hosts a landline exchange (incumbent Bell Canada's OTWAON08 -CG0) and three rival mobile switches (-0MD is Rogers, -3MD is Telus, -AMD is Bell Mobility), one for each major wireless carrier.[16]

Similar naming conventions apply for CLEC exchanges at a point of interconnection to incumbent carrier networks. The suffix -MD nominally refers to "miscellaneous other termination entities".[6]

MALTON22CG1

The city of Mississauga is a sprawling half-million person suburb directly west of Toronto. It is in Peel Region and therefore in a different local interconnection region, a different area code (905 instead of 416) and different, multiple rate centres (Clarkson, Streetsville, Cooksville, Malton, Port Credit; Bell Canada has no named "Mississauga" exchange despite the city's incorporation in 1973).

This individual exchange, MALTON22CG1, serves multiple rate centres with different local calling areas for each. It is located 1800 metres west of the boundary between Toronto and Mississauga, serving a major international airport (in Mississauga) and that airport's hotel strip (directly across the town line, therefore in Toronto). Callers from Markham would be a local call to the hotels but long-distance to the airport itself, even though both destinations are served by the same physical Digital Multiplex System switch.

This CLLI code identifies a wire centre (the location of the switch) only. A similar exchange on the other side of the town line (such as TOROON29DS0, located 900 metres east of Toronto's western city limits at 40 Old Burnhamthorpe Road, Etobicoke and serving multiple rate centres) would be issued a Toronto CLLI to reflect the location of the switch itself, but follow the same pattern of a more restrictive calling area for individual subscribers outside city limits. Wire centre CLLI codes therefore do not suffice to identify a rate centre or V/H co-ordinates for toll billing; any +1-416 numbers are billed as if they were in downtown Toronto.

WFISON15RS0

This is an unattended, automated remote switch housed in a small, square windowless brick building on a side street in Marysville village. It serves about 1400 people on Wolfe and Simcoe Islands in the Thousand Islands.

A Remote Switching Centre (RSC) has limited capability. It can operate autonomously to connect calls within the same exchange, but otherwise relies entirely on control via a single uplink to a host office (in this case, mainland Digital Multiplex System exchange KGTNON08CG0).[19]

An electronic or digital exchange in a small city surrounded by rural villages most often will act as an upstream host for multiple remote switching centres, one in each local village.

References

  1. 1 2 "CLLI Codes Technical Description". Telcordia. Retrieved 22 February 2009.
  2. 1 2 "Vertical and Horizontal Coordinates". Telcordia. Retrieved 22 February 2009.
  3. ↑ "High-Tech Dictionary - VOIP". ComputerUser, Inc. Retrieved 22 February 2009.
  4. ↑ "Intercompany Responsibilities Within The Telecommunications Industry" (PDF). ATIS/NIIF 0015 Issue 1.0. Retrieved 2016-04-16.
  5. 1 2 3 "Intercompany Responsibilities Within The Telecommunications Industry" (PDF). ATIS/NIIF 0015 Issue 1.0. Retrieved 2012-06-15.
  6. 1 2 3 4 CLLI code description, Bell System Practices (AT&T standard) Section 795-100-100 Issue 5, October 1982
  7. ↑ "West University Place city." United States Census Bureau. Retrieved on February 1, 2009.
  8. ↑ "Southwestern Bell exchange list". Southwestern Bell Telephone. Retrieved 22 February 2009.
  9. ↑ "Telephone EXchange Name Project". Retrieved 22 February 2009.
  10. ↑ "Telcodata lookup". Telcodata.us. Retrieved 22 February 2009.
  11. ↑ "Telcodata lookup". Telcodata.us. Retrieved 22 February 2009.
  12. ↑ "Telcodata lookup". Telcodata.us. Retrieved 22 February 2009.
  13. ↑ SWASONXTSG1 on telcodata.us
  14. ↑ http://www.localcallingguide.com/lca_prefix.php?npa=705&nxx=642
  15. ↑ OTWAON080MD on localcallingguide.com
  16. ↑ OTWAON08 - Iona Street, Ottawa on localcallingguide.com
  17. ↑ MALTON22CG1 on localcallingguide.com
  18. ↑ WFISON15RS0 on localcallingguide.com
  19. ↑ Despite the -CG0 suffix, Kingston's "LIberty 8" exchange (+1-613-54x-xxxx) is a Nortel DMS-100 per KGTNON08CG0 on telcodata.us

External links

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