Telecom Decision CRTC 2006-34

Ottawa, 26 May 2006

Follow-up to Finalization of quality of service rate rebate plan for competitors, Telecom Decision CRTC 2005-20 - Service intervals for provisioning CDN services and Type C loops

Reference: 8638-C12-200505349

In this Decision, the Commission finalizes the service intervals for Competitor Digital Network (CDN) services and Type C loops that competitors acquire from the incumbent local exchange carriers (ILECs). These intervals are based on intervals for similar services that the ILECs provide to their retail customers.

In addition, the Commission determines that the service confirmation time is part of the service interval for the delivery of a CDN service or Type C loop, and that noon in the ILEC's serving territory is the cut-off reference time to calculate these service intervals.

The Commission also adjusts service intervals for TELUS Communications Company (TCC) so that, as with the other ILECs' service intervals, they do not differ by the location (urban/rural) where the CDN services and Type C loops are provisioned.

Finally, Saskatchewan Telecommunications and TCC are to review, reduce, and refile their service intervals for all CDN services within one year of the date of this Decision in order to align more closely with the other ILECs.

Background

1. In Finalization of quality of service rate rebate plan for competitors, Telecom Decision CRTC 2005-20, 31 March 2005 (Decision 2005-20), the Commission introduced competition-related quality of service indicator 1.19, Confirmed Due Dates Met - CDN Services and Type C Loops. This indicator measures the frequency with which the incumbent local exchange carriers (ILECs) meet confirmed due dates for provisioning Competitor Digital Network (CDN)1 services and Type C loops2 to competitors. The standard set for this indicator is 90 percent.

2. The Commission notes that the record of the proceeding that led to Decision 2005-20 did not include service intervals for CDN services or Type C loops. In Decision 2005-20, the Commission considered that the ILECs should provide services to their competitors within timeframes similar to those they provided to themselves - that is, to their retail customers - and initiated a follow-up process to seek proposals from the ILECs to define service intervals for provisioning CDN services and Type C loops.

Process

3. The Commission made the following companies parties to this proceeding: Aliant Telecom Inc. (Aliant Telecom), Bell Canada, MTS Allstream Inc. (MTS Allstream), Saskatchewan Telecommunications (SaskTel), and TELUS Communications Inc., now TELUS Communications Company (TCC)3 (collectively, the ILECs); Société en commandite Télébec (Télébec); and TELUS Communications (Québec) Inc. (formerly TELUS Québec, now TCC in its Quebec operating territory).

4. The Commission received proposals from Bell Canada, MTS Allstream, SaskTel, TCC, and Télébec on 2 May 2005, and from Aliant Telecom on 3 May 2005. MTS Allstream amended its proposal on 6 May 2005.

5. The Commission received comments from MTS Allstream (competitive local exchange carrier (CLEC))4 and Bell Canada (CLEC) on 10 and 11 May 2005, respectively.

6. The Commission received reply comments from Bell Canada, SaskTel, and TCC on 16 May 2005, and from Aliant Telecom on 18 May 2005.

7. The Commission issued interrogatories to the ILECs on 27 May 2005 and received responses on 10 June 2005 from Bell Canada, MTS Allstream, SaskTel, and TCC. Aliant Telecom filed its response on 19 October 2005, with the explanation that the delay was due to an internal administrative error.

Issues

8. In this proceeding the Commission has considered three issues in order to establish service intervals for CDN services and Type C loops. These issues are:

  1. Service interval definition and cut-off time for triggering the start of a service interval;
  2. Service intervals for CDN services and Type C loops where facilities are available; and
  3. Service intervals for CDN services and Type C loops where facilities are not available.

A. Service interval definition and cut-off time for triggering the start of a service interval

Positions of parties

9. All the ILECs except TCC submitted that service intervals to provision CDN services and Type C loops should be measured from the time that a firm order was received from the customer. TCC submitted that the service interval began when it confirmed the service order with the customer.

10. TCC noted that TELUS Québec had not been a party to the CDN service proceeding leading to Competitor Digital Network Services, Telecom Decision CRTC 2005-6, 3 February 2005 (Decision 2005-6). TCC submitted, therefore, that the CDN services and Type C loop service intervals it proposed in this proceeding would not apply to requests for service in the former TELUS Québec territory.

MTS Allstream (CLEC)'s comments

11. MTS Allstream (CLEC) noted that while the ILECs generally had proposed that the service intervals for CDN services and Type C loops would be triggered by the receipt of a firm order, TCC had proposed that these service intervals should begin once the service order was entered into its provisioning system. MTS Allstream (CLEC) argued that this approach could result in unreasonable delays if, for example, the order entry position were understaffed. MTS Allstream (CLEC) submitted that, consequently, these service intervals should not be contingent on the date an order was entered into a particular ILEC's database but should instead be triggered by the receipt of a firm order.

12. MTS Allstream (CLEC) also submitted that the time required by an ILEC to issue the confirmation of the firm installation date for the ordered service should be included in the service interval, as it was for all other services.

Reply comments

13. In response to the comments by MTS Allstream (CLEC) regarding the start of the service interval, Bell Canada clarified that it considered day zero to be the calendar day that the order was received from the customer, if the order was received before 3 p.m. If the order was received after 3 p.m., the following business day would be considered day zero. Bell Canada added that the service intervals it had proposed included the time required to determine the availability of facilities and provide a confirmed due date to the customer.

14. In response to MTS Allstream (CLEC)'s concerns about what event should trigger the service interval, TCC submitted that Aliant Telecom, Bell Canada, SaskTel, and TCC had all adopted the position that the service interval started with the receipt of a firm customer order. TCC also submitted that the period of discussion and negotiation between the carrier and the customer prior to the customer issuing a firm service order was clearly before the time the service interval started. It suggested that the service interval should only start once the customer had provided sufficient information to enter the order into the provisioning system.

Commission's analysis and determinations

15. The Commission notes that TELUS Québec and Télébec were not directed to provide CDN services in Regulatory framework for second price cap period, Telecom Decision CRTC 2002-34, 30 May 2002 (Decision 2002-34) or in Decision 2005-6. Consequently, TCC in its Quebec operating territory and Télébec will be required to submit their provisioning service intervals for CDN services and Type C loops in a future proceeding, when demand occurs in these operating territories.

16. The Commission notes that all the ILECs except TCC proposed that the service intervals for CDN services and Type C loops be triggered by the receipt of a firm order. TCC differed from the other ILECs in proposing that the service interval be triggered by the entry of the service order into its provisioning system. The Commission considers that the triggering of a service interval should not be contingent on an ILEC's specific provisioning process and consequently considers TCC's service interval triggering proposal inappropriate.

17. With respect to MTS Allstream (CLEC)'s request that the time required by an ILEC to issue the confirmation of the firm installation date for the ordered service be included in the service interval, the Commission considers that it is appropriate to be consistent with current practice and include this period of time in the service interval.

18. The Commission notes that it has considered the cut-off time for provisioning unbundled loops in various past proceedings. A cut-off time of noon was adopted for local service requests (LSRs) for migrated unbundled loops with a service interval of two business days in Incumbent local exchange carrier service intervals for unbundled local loop orders, Telecom Decision CRTC 2002-14, 8 March 2002 (Decision 2002-14). In addition, the Commission notes that in an e-mail dated 29 August 2005, Commission staff proposed to the CRTC Interconnection Steering Committee Business Process Working Group participants that a cut-off time of noon should be adopted as the start of the service interval for all services ordered via an LSR.

19. The Commission considers that a similar approach should be used by ILECs when provisioning CDN services. Consequently, if an order for a CDN service or a Type C loop is received prior to or at noon in an ILEC's serving territory, that day will be counted as day one. If the order is received after noon in the ILEC's serving territory, the next business day will be counted as day one. The Commission has adjusted Bell Canada's proposed service intervals accordingly, resulting in a one-day increase based on the company's current "day zero" counting process. These adjusted service intervals are shown in the Appendix to this Decision.

20. In light of the above, the Commission determines that for a CDN service or Type C loop:

  1. the service interval to provision a service is triggered by the receipt by the ILEC of a firm order;
  2. the interval of time required by the ILEC to confirm a due date is part of the service interval; and
  3. for consistency with its determination in Decision 2002-14 regarding LSRs for migrated unbundled loops, noon is the cut-off reference time to calculate provisioning service intervals.

B. Service intervals for CDN services and Type C loops where facilities are available

Positions of parties

21. The ILECs submitted that where facilities were available, their proposed service intervals for provisioning CDN services and Type C loops to competitors were consistent with the existing service intervals for their retail customers.

22. The ILECs, with the exception of SaskTel, which remained silent on the issue, added that any associated features such as channelizing5 and intra-exchange or interexchange channels,6 when ordered with CDN access(es), would be provided within the same service interval as the access(es), if the facilities required for channelizing or for channel transport were available. They submitted further that if these features were ordered separately, the service intervals for these features alone would be the same as for the access(es).

23. Aliant Telecom proposed fixed service intervals of 10 business days for provisioning CDN accesses or channels at the DS-0 rate and 15 business days for provisioning accesses or channels at DS-1, DS-3, OC-3, and OC-12 rates,7 within designated areas, where facilities and equipment were available. It also proposed a service interval of 15 business days for Type C loops, where facilities and equipment were available.

24. Bell Canada proposed fixed service intervals of between 7 and 12 business days for provisioning CDN accesses or channels at DS-0, DS-1, DS-3, OC-3, and OC-12 rates, within designated areas and where facilities were available. The company clarified that the service interval of 7 business days was for Type C loops delivered as an unchannelized DS-1, where facilities were available.

25. MTS Allstream proposed fixed service intervals of between 12 and 30 business days for provisioning CDN services at DS-0, DS-1, and DS-3 rates, where feeder and distribution facilities were available. It also submitted that it currently does not provide fixed delivery intervals for CDN services at OC-3 or OC-12 rates in its territory due to lack of demand, but that it could reassess the need for a fixed interval should demand for these services increase over time.

26. SaskTel proposed fixed service intervals for provisioning CDN services at DS-0 and DS-1 rates of 12 and 20 business days, respectively, where facilities existed and within designated service areas. SaskTel submitted that due to its lack of experience in provisioning CDN services at higher rates, the service interval would be negotiated with the customer.

27. TCC proposed service intervals, where facilities were available, of between 12 and 35 business days in major/metro urban areas and minor urban areas, and between 15 and 45 business days in rural areas, for provisioning CDN services (accesses at DS-0, DS-1 and fractional rates,8 and DS-3 rates), and from 12 to 30 business days in the same areas for Type C loops. TCC also proposed service intervals in major/metro urban, minor urban, and rural areas ranging from 20 to 45 business days for CDN services (accesses) at OC-n rates. Finally, TCC proposed using the same service intervals as the CDN-equivalent accesses for provisioning private lines at 56 kb/s, DS-1, and DS-3 rates, and interexchange channels at OC-n rates.

Bell Canada (CLEC)'s comments

28. Bell Canada (CLEC) noted that while there was a good degree of similarity in the service intervals proposed by the ILECs, TCC had chosen to categorize service intervals as a function of location. Bell Canada (CLEC) requested that the Commission require TCC to propose service intervals for CDN services and Type C loops similar to those proposed by the other ILECs in order to ensure standardization of service across all territories where CLECs operated. Bell Canada (CLEC) requested that, in the alternative, TCC be required to clearly define the major/metro urban, minor urban, and rural areas by mapping its own CDN/Digital Network Access (DNA) rate bands to each of the three areas.

29. Bell Canada (CLEC) also noted that the service intervals proposed by TCC were almost four times longer than the service intervals proposed by the other ILECs. Bell Canada (CLEC) submitted that TCC's provisioning process should be in line with the provisioning processes of the other ILECs, and that service intervals for CDN services and Type C loops should be standardized across all ILECs.

Reply comments

30. SaskTel submitted that Bell Canada (CLEC)'s proposal to standardize service intervals for all ILECs was self-serving and should be rejected by the Commission since it did not specify which of the ILECs' service intervals should serve as the standard or what criteria should be employed to determine the appropriate standard.

31. In response to Bell Canada (CLEC)'s comments, TCC submitted that the service intervals it offered to its retail and wholesale customers varied depending on the geographic region in which it was asked to provide the service. TCC indicated that it had technical staff residing in major urban areas who were readily available to undertake new service requests, but that in rural areas it relied on itinerant staff who undertook new service requests on a weekly or biweekly basis, or as specifically scheduled. TCC indicated further that provisioning equipment to deliver higher speed services was a more lengthy process in rural areas than in urban areas.

32. TCC submitted that it had divided its home territory into three sub-areas in order to organize its workload and to provide retail and wholesale customers with a reasonable expectation of the time required to implement service. TCC submitted that it saw no particular reason that it should accede to Bell Canada (CLEC)'s request to offer the same service interval to a customer in downtown Edmonton as to a customer requesting service in a newly discovered oil patch 100 kilometres outside the city.

33. With respect to Bell Canada (CLEC)'s request that TCC be required to clearly define its three geographic areas by mapping its CDN/DNA rate bands to each of the three areas, TCC noted that the major/metro urban areas were defined as the downtown sections of Vancouver, Calgary, and Edmonton; the urban areas were defined as the cities and locations within cities other than the three specified above; and the rural areas encompassed the remaining parts of its territory. TCC submitted that it would be prepared to clearly define these areas by mapping its CDN/DNA rate bands to each of the three areas once the Commission had ruled on its proposed sub-areas in this proceeding.

34. Concerning Bell Canada (CLEC)'s request to standardize service intervals nationally, TCC submitted that a national standardized service interval would not reflect local geography, resource demographics, and other structural limitations that existed within each company. TCC also submitted that the standardized approach suggested by Bell Canada (CLEC) would not recognize the unique circumstances faced by each company and was therefore impractical and unworkable.

Commission's analysis and determinations

35. The Commission notes that the ILECs considered that the service intervals they proposed, where facilities were available, were consistent with the service intervals they provided to their retail customers for comparable services. MTS Allstream and SaskTel did not propose service intervals for Type C loops.

36. As noted earlier in this Decision, a Type C loop is not a CDN service but is used to support DS-1 CDN service. The Commission therefore considers it reasonable that the service intervals for Type C loops should be equivalent to those for CDN services at the DS-1 rate.

37. Accordingly, the Commission determines that MTS Allstream and SaskTel are to provision Type C loops within the same service intervals as those approved in this Decision for CDN services at the DS-1 rate, where facilities are available.

38. The Commission notes that most ILECs, except SaskTel, submitted that in the provisioning of CDN services, any associated features such as channelizing and intra-exchange or interexchange channels, when ordered with CDN access(es), would be provided within the same service interval as the access(es), if the facilities required for channelizing or channel transport were available. The Commission also notes that for Bell Canada, two additional business days are required to channelize a DS-1 access. The Commission further notes that most ILECs submitted that if the associated features were ordered separately, the applicable service interval would be the same as the one that applied to the provisioning of the access(es). The Commission notes that SaskTel's proposed service intervals for CDN services were filed three months after Decision 2005-6 was issued and should therefore normally include the associated features.

39. Accordingly, the Commission determines that SaskTel is to provision associated features such as channelizing and intra-exchange or interexchange channels within the same service interval as access(es), in the same manner as most other ILECs, whether these features are ordered with CDN access(es) or separately.

40. The Commission notes further that where facilities are available, MTS Allstream and SaskTel proposed that, due to lack of demand or experience in provisioning high-rate CDN services, service intervals be negotiated for high-rate accesses and interexchange channels, which included OC-3 and OC-12 rates for MTS Allstream, and DS-3, OC-3, and OC-12 rates for SaskTel. Parties to the proceeding did not object to this proposal. The Commission agrees that service intervals for OC-3 and OC-12, in the case of MTS Allstream, and for DS-3, OC-3, and OC-12, in the case of SaskTel, should be negotiated when these services are ordered in their operating territories.

41. The Commission notes that if competitors' attempts to negotiate such service intervals should fail, the competitors may bring the matter before the Commission for resolution.

42. The Commission notes that CDN services and Type C loops are critical unbundled network elements required by CLECs to compete with ILECs in the local service market in both rural and urban areas. The Commission is concerned about the disparity that exists between the service intervals TCC has proposed for CDN services and those the other ILECs have proposed. TCC's proposed service intervals in rural areas are in some cases more than twice as long as those in major/metro urban areas and almost four times as long as other ILECs' service intervals for similar services.

43. The Commission notes that in Decision 2002-14, it stated that it was satisfied that service intervals to provide unbundled local loops should be the same for both urban and rural areas since no rationale had been provided to justify longer service intervals in rural areas. In addition, the Commission noted in that decision that the ILECs had not demonstrated that service intervals for their own customers in rural areas were longer than those in urban areas.

44. The Commission notes that in an interrogatory dated 27 May 2005, it gave TCC an opportunity to provide service intervals throughout its operating territory under the same two categories as other ILECs. TCC's response was similar to its original proposal in that service intervals for CDN services where facilities were available were split into the same three previously proposed geographic areas based on rate groups. TCC supported its unique proposal using arguments such as geography and equipment delivery timeframes, which might be equally applicable to the other ILECs, in addition to its argument regarding specific workforce arrangements involving itinerant workers.

45. The Commission notes that, where facilities are available, no differentiation was made in provisioning service intervals between urban and rural areas by i) Aliant Telecom and Bell Canada for CDN services at DS-n and OC-n rates, and for Type C loops; ii) MTS Allstream for CDN services at DS-n rates and for Type C loops; and iii) SaskTel for CDN services at DS-0 and DS-1 rates. TCC was the only ILEC that proposed different service intervals for urban and rural areas based on diverse geography, equipment availability and delivery timeframes, and workforce arrangements.

46. The Commission considers that the ILECs generally face similar operating issues, including equipment availability and delivery timeframes, diversity of geography, and resource management. As a result, the Commission is not persuaded that any ILEC requires a basis for establishing service intervals that is completely different from the one used by the other ILECs to propose service intervals for the same services.

47. Consequently, the Commission determines that where facilities are available, TCC is to use its proposed service intervals for CDN services and Type C loops in major/metro urban areas as the default for all of its operating territory outside Quebec. The Commission has adjusted TCC's proposed service intervals accordingly, as shown in the Appendix to this Decision.

48. The Commission considers that with this change, ILECs operating as CLECs in other ILECs' territories will benefit from service intervals for unbundled network elements that are similar to those they provide to CLECs operating in their own territories.

49. The Commission notes that even with this change, TCC's service intervals for CDN services at rates higher than DS-1 still remain longer than those proposed by all other ILECs.

50. The Commission also notes that MTS Allstream's and SaskTel's service intervals for CDN services at all rates, and MTS Allstream's Type C loop service intervals, are significantly longer than those proposed by Aliant Telecom and Bell Canada for similar services.

51. Consequently, the Commission determines that MTS Allstream, SaskTel, and TCC are to review and reduce their service intervals for CDN services and Type C loops that they provide to their competitors to align more closely with the other ILECs. The Commission directs MTS Allstream, SaskTel, and TCC to refile proposed reduced service intervals within one year of the date of this Decision.

52. In light of the above, the Commission determines that where facilities are available:

  1. the service intervals for CDN services and Type C loops, as adjusted by the Commission and indicated in the Appendix to this Decision, are approved, with an implementation date of 1 June 2006;
  2. MTS Allstream and SaskTel are to provision Type C loops within the same service intervals as those approved in this Decision for their CDN services at the DS-1 rate;
  3. SaskTel is to provision associated features such as channelizing and intra-exchange or interexchange channels within the same service interval as access(es), in the same manner as most other ILECs, whether these features are ordered with CDN access(es) or separately;
  4. TCC is not permitted to adopt different service intervals for urban and rural areas for CDN services and Type C loops, but is to adopt the service intervals it proposed for its major/metro urban areas as the default for all of its operating territory outside Quebec. This has resulted in an adjustment of TCC's proposed service intervals; and
  5. MTS Allstream, SaskTel, and TCC are to review, reduce, and refile, within one year of the date of this Decision, the service intervals for CDN services and Type C loops that they provide to their competitors to align more closely with the other ILECs.

C. Service intervals for CDN services and Type C loops where facilities are not available

Positions of parties

53. The ILECs proposed that where facilities are not available, service intervals should be negotiated with the requesting competitor, similar to the current process with retail customers.

54. Aliant Telecom submitted that when network construction was required, it would coordinate with equipment suppliers and its construction department to establish the installation due date.

55. SaskTel submitted that where facilities are not available to provide DS-0 and DS-1 CDN services, the service interval would be negotiated with the customer. SaskTel submitted further that, due to its lack of experience in provisioning CDN services at DS-3, OC-3, and OC-12 rates, the associated service intervals would also have to be negotiated with the customer.

CLECs' comments

56. The CLECs did not provide comments with respect to cases where facilities are not available to provide CDN services and Type C loops.

Commission's analysis and determinations

57. The Commission notes that where facilities are not available, all ILECs agreed that the service intervals should be negotiated.

58. The Commission notes that all ILEC tariffs relative to the provision of unbundled loops and CDN services contain a caveat that the provision of these facilities and services is contingent on suitable facilities being available.

59. The Commission notes that where facilities required for CDN service or Type C loops are not available, ILECs need to conduct economic studies before deciding to invest in a network extension. They also need to design work plans, secure rights of way and permits, and order equipment before building, testing, and putting the new network into service. The Commission notes that many of these steps are not completely within the ILECs' control. The Commission considers that this supports the need for the ILECs and their customers to negotiate the in-service date.

60. As a result, the Commission considers that it would not be appropriate to impose predetermined service intervals where facilities are not available.

61. The Commission notes that if competitors' attempts to negotiate service intervals for CDN services or Type C loops should fail, the competitors may bring the matter before the Commission for resolution.

62. In light of the above, the Commission determines that where facilities are not available, service intervals to provision CDN services and Type C loops should be negotiated between the ILEC and its customer.

63. Finally, the Commission notes that, as determined in Decision 2005-6, ILECs have included in their tariffs a provision to allow them to recover special equipment costs and unusual expenses when installing equipment to provide CDN services for competitors where facilities are not available.

Secretary General

This document is available in alternative format upon request, and may also be examined in PDF format or in HTML at the following Internet site: www.crtc.gc.ca

Footnotes

[1] Prior to Competitor Digital Network Services, Telecom Decision CRTC 2005-6, 3 February 2005 (Decision 2005-6), Competitor Digital Network (CDN) access was referred to as Competitor Digital Network Access (CDNA), while Digital Network Access (DNA) was the term used for the similar retail service. In Decision 2005-6, the Commission indicated that CDN service is provided on a fibre or copper facility that permits the transmission of data at various rates (DS-0 to OC-12), and that competitors acquire this service from incumbent local exchange carriers (ILECs) in order to provide service to their customers or to connect their own facilities to the ILEC network. A CDN service is a circuit usually comprised of one or more access(es), link(s), and an interexchange or intra-exchange channel. A CDN service connects the end customer to the serving competitor's facilities located in a central office (CO), a point of presence (POP), or a co-location enclosure in an ILEC's CO. Alternatively, the CDN service provides the connection between the serving competitor's facilities and the ILEC's switch or POP in order to exchange traffic.

[2]  A Type C loop is a digital transmission path that can be used to support a DS-1 CDN service that connects an end customer to its service provider's network. It is often ordered by competitive local exchange carriers (CLECs) for other purposes and through a process that is different from the one used to order the almost identical DS-1 CDN services.

[3] Effective 1 March 2006, TELUS Communications Inc. assigned and transferred all its assets and liabilities, including all its service contracts, to TELUS Communications Company (TCC).

[4] The Commission notes that some of the ILECs operate as ILECs in their home territories and also as CLECs when providing service outside their home territories. In the case of Bell Canada and MTS Allstream, "(CLEC)" follows the companies' names in order to distinguish their comments in their roles as CLECs, as applicable.

[5] Channelizing (channelization) is the process by which a broadband transmission stream is subdivided into a number of smaller streams called channels, to allow for the transmission of separate voice grade conversations or data grade streams.

[6] An intra-exchange channel is a transmission path between wire centres within an ILEC rate centre, while an interexchange channel is a transmission path between two ILEC rate centres. TCC uses the term "metropolitan interexchange IX channel" instead of "intra-exchange channel" in its metropolitan calling areas.

[7] "Rate" refers to a volume of bits over a unit of time [Kilo-bits/s (kb/s) or Mega-bits/s (Mb/s)]. The term "speed" is often incorrectly  used instead of the word "rate."

"DS-n" (Digital Signal Level n) is a signal format that operates at n kb/s. DS-n is the basic building block in the international digital hierarchy. The number n is equal to 0 (DS-0) when the signal format is 64 kb/s (or 56 kb/s), which is equivalent to a voice frequency channel. It is equal to 1 (DS-1) when the signal format is 1.544 Mb/s, which is equivalent to 24 DS-0s. It is equal to 3 (DS-3) when the signal format is 44.736 Mb/s, which is equivalent to 672 DS-0s.

"OC-n" (Optical Carrier Level n) is a term used in the SONET (Synchronous Optical Network) hierarchy to identify the transmission rate of the optical signals, transported in multiples of 51.84 Mb/s. The SONET hierarchy is a North American standard for synchronous optical networks having minimum transmission rates of 51.84 Mb/s. The number n is equal to 1 (OC-1) when the system carries the basic building-block transmission of 51.84 Mb/s. It is equal to 3 (OC-3) when the transmission rate is 155.52 Mb/s, or three times OC-1. It could also be equal to 12, 48, 192, or 768.

[8] In this case, the term "fractional rates" refers to two, four, or eight DS-0s.

Appendix

Approved service intervals for CDN services and Type C loops
Follow-up to Telecom Decision CRTC 2005-20

  Aliant Telecom Bell Canada MTS Allstream SaskTel TCC
1) Where facilities are available
DS-0 access 10 9 12 12 12
DS-1 access 15 Unchannelized: 8
Channelized: 10
20 20 12
Type C loop 15 8 20 20 12
DS-3 access 15 13 30 TBN 35
OC-3 access 15 13 TBN TBN 20
OC-12 access 15 13 TBN TBN 20
IX channel 56 kb/s 10 9 20 12 12
IX channel DS-1 15 Unchannelized: 8
Channelized: 10
20 20 12
IX channel DS-3 15 13 30 NA 35
IX channel OC-3 15 13 TBN NA 20
IX channel OC-12 15 13 TBN NA 20
2) Where facilities are not readily available
All accesses TBN TBN TBN TBN TBN
Type C loop TBN TBN TBN TBN TBN
All IX channels TBN TBN TBN TBN TBN

Notes:

Date modified: