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Telcordia PV-IDLC GR Documents

Telcordia has completed the development of two new generic requirements (GR) documents addressing the use of Packet Voice technology in the Local Exchange Carrier (LEC) access network.

  • GR-3109-CORE, Generic Criteria for Packet Voice Integrated Digital Loop Carrier (PV-IDLC) Systems
  • GR-3110-CORE, Generic Criteria for Packet Voice Integrated Digital Loop Carrier (PV-IDLC) Systems Operation and Management

These documents are available for purchase from the Telcordia Information Superstore. More information on these two important Generic Requirements (GR) documents are provided below.

GR-3109-CORE

IDLC-based access architectures have historically been focused on providing locally switched telephony services to residential and small/medium business customers. These IDLC systems are increasingly being offered as part of network access platforms that are built on a broadband access carriage, providing both broadband and narrowband services delivery capabilities. Issue 1 of GR-3109-CORE considers the narrowband service delivery aspect of these broadband integrated access systems. Future issues of this document may address the broadband service delivery and interface aspects of these systems.

GR-3109-CORE describes how existing Telcordia DLC generic requirements (e.g., GR-303-CORE, GR-57-CORE, and GR-909-CORE) should be applied to PV-IDLC systems and augments these generic requirements based on the unique challenges presented by packet voice transport and emerging broadband packet access architectures. The work defines a packet voice endpoint (PVE) function that exists in the network as part of a broadband Remote Digital Terminal (PVE-A), in the network as part of a FTTx ONU-like device (PVE-B), or in a customer-owned device (PVE-C). A Network Gateway (NGW) provides the network-side packet voice-to-TDM voice conversion and IDLC interface functions, as well as serving as a point for providing additional functionality in support of transitioning customer lines to the emerging softswitch service environment (e.g., network protection, voice quality monitoring, conference bridging, and signaling concentration).

GR-3109-CORE provides system criteria on the PVE function(s), the NGW function, and the broadband access network (BAN) that interconnect these elements. System criteria addressed includes: voice quality planning; voice quality control (e.g., loss insertion, packet loss, delay, and packet delay variation); packet voice impairment mitigation; system failure behaviors; and system behaviors during overload and congestion conditions. The new or modified criteria provided in GR-3109-CORE are intended to help insure that packet voice IDLC (PV-IDLC) systems provide the same telephone service quality as their TDM counterparts (i.e., “PSTN-quality”). Criteria support for both GR-303-CORE and GR-8-CORE IDLC interfaces to the Public Switched Telephone Network (PSTN) are provided.

While the focus of GR-3109-CORE, Issue 1, is on packet voice access systems that interface with TDM Class 5 switching systems via an IDLC interface, the criteria has been developed with an eye toward the eventual transition to a softswitch service environment. The need for network elements that comprise the PV-IDLC system to simultaneously support customer lines served from both a TDM Class 5 switching system and a softswitch based network is considered. In addition, the impacts of voice impairment allocation in a PV-IDLC system on the ability of the system to meet voice performance objectives in an end-to-end packet network is considered.

Overview of GR-3109-CORE

  • Section 1, “Introduction,” provides an introduction to the purpose and scope, target audience, structure and organization, requirements terminology and labeling conventions used in this Generic Requirements document.
  • Section 2, “PV-IDLC System Overview,” provides an overview of the architecture and functional elements of a PV-IDLC system and the interfaces to embedded PSTN devices. It also describes the assumptions and constraints on the architecture, as well as the scope of the PV-IDLC system being considered. A functional overview of PV-IDLC system components is provided, and two primary applications for a PV-IDLC system are described (i.e., a Packet Voice DLC and Derived Voice over Broadband application). PV-IDLC system alternatives for supporting analog line signaling and supervision are described.
  • Section 3, “Telephony Service Requirements,” specifies the required and optional telephony services provided by a PV-IDLC system. The need to support Class 5 switching system services that utilize on-hook data transmission is described.
  • Section 4, “Telephony Signaling and Supervision Criteria,” specifies PV-IDLC system criteria related to the support of analog line signaling and supervision. Criteria is considered for PV-IDLC systems that use “interpreted signaling” and “transition-oriented signaling”. Message-oriented and in-band addressing criteria is also provided. The use of in-band and message-oriented call progress tone approaches are also considered. This section also specifies PV-IDLC call processing behavior during failure, congestion, and call processing overload events. Service-related timing criteria (e.g., reporting origination requests, applying dial tone, establishing an off-hook transmission path) are also provided.
  • Section 5, “Voice Quality and Performance Criteria,” describes the conversational quality of a telephone connection in terms of listening, talking, and interaction quality. The criteria related to factors that control the conversational quality of a telephone link are specified, including packet loss, loss plan (loudness/echo control), and delay. The use of E-model in PV-IDLC network transmission engineering is specified, including the minimum transmission rating necessary for PSTN-quality voice. Packet transport layer bandwidth management issues and system-level criteria are provided. The concept of concentrated PV-IDLC systems and admission control are described.
  • Section 6, “Bearer Information Processing Criteria,” provides PV-IDLC system voice processing criteria in support of providing the voice quality and performance levels specified in Section 5. These include voice sample encoding, packetization, packet loss concealment, voiceband echo cancellation, silence suppression and comfort noise insertion. PV-IDLC system criteria related to support of voiceband data and fax modem applications are provided.
  • Section 7, “Generic Interface to the Local Digital Switch,” specifies the minimum GR-303-CORE generic interface functionality required in a PV-IDLC environment. Optional support for the GR-8-CORE IDLC interface is also considered. Limitations of the GR-8-CORE IDLC interface in a PV-IDLC application are discussed.
  • Section 8, “Traffic Sensitive Criteria,” specifies criteria that apply to all PV-IDLC systems whose performance, due to any aspect of the PV-IDLC system design, is sensitive to the traffic load presented to it. Criteria covers both system traffic capacity and system call rate capacity.
  • Section 9, “Miscellaneous Criteria,” provides physical, environmental, powering, electromagnetic compatibility, electrical safety, and reliability/quality criteria for PV-IDLC network elements housing NGW, PVE-A and PVE-B functions. PV-IDLC synchronization criteria are also provided.
  • Section 10, “Operations Support and Transition,” specifies PV-IDLC operations support criteria, which at this time primarily points to the companion document GR-3110-CORE. A discussion of transitioning a PV-IDLC system to a softswitch environment is also provided, including the potential role of the NGW in this next-generation network environment.

GR-3109-CORE is available for purchase from the Telcordia Information Superstore.

GR-3110-CORE

As the public telecommunications network continues to evolve, the use of packet switching technology to facilitate the merging of carrier-class voice communications with other broadband telecommunications applications on a common transport, switching, and control infrastructure is becoming a common trait. This introduction of packetized voice transport in the access network presents new challenges for access system suppliers, and introduces new operations and management support issues for network operators.

GR-3110-CORE, “Generic Criteria for Packet Voice IDLC (PV-IDLC) Operations and Management”, Issue 1 addresses the operations and management impacts of migrating packet voice transport functionality into a distributed IDLC access architecture. GR-3110-CORE builds upon existing IDLC operations criteria to address the specific operations and management requirements on PV-IDLC systems and packet voice services.

Although the focus of GR-3110-CORE, Issue 1 is on packet voice access systems that interface with TDM Class 5 switching systems via an IDLC interface, consideration has been given to the eventual transition to a softswitch service environment. The need for network elements that comprise the PV-IDLC to simultaneously support services from both a TDM Class 5 switching system and a softswitch based network is considered.

The comprehensive operations and management criteria specified in GR-3110-CORE, Issue 1, will enable service providers and access system suppliers to cost-effectively and rapidly:

  • develop packet voice capable access systems that meet both the short-term and long-term business needs of service providers.
  • deploy packet voice capable access systems that can provide significant revenue streams for several years while also serving as an important transitional technology for the migration to softswitch architectures.

Overview Of GR-3110-CORE

  • Section 1, “Introduction,” provides an introduction to the purpose and scope, target audience, structure and organization, requirements terminology and labeling conventions used in this GR document.
  • Section 2, "PV-IDLC Operations Architecture", provides an overview of the management of PV-IDLC systems, the reference network architecture and the reference management architecture.
  • Section 3, "Configuration Management", defines the requirements for the PV-IDLC system to support provisioning of customer line, equipment and facility resources.
  • Section 4, "Fault Management", defines the requirements to support alarm surveillance, fault localization, and testing on PV-IDLC interfaces and equipment.
  • Section 5, "Surveillance Criteria", addresses the alarm surveillance and performance monitoring requirements supported by the PV-IDLC system.
  • Section 6, "Security Management", provides generic functional requirements for the PV-IDLC to support the management of the security mechanisms in the functional entities within its management domain.

GR-3110-CORE is available for purchase from the Telcordia Information Superstore.