ATIS - 0100509
Packetized Circuit Multiplication Equipment – Interface Specification
|Publication Date:||1 January 1995|
This standard is intended as a base document for the specification and interconnection of packetized circuit multiplication equipment (PCME) and Packet Circuit Multiplication Systems (PCMS) from various manufacturers.
This standard covers the following interface and functional requirements for PCME:
- interface requirements (network-network and user-network), including
- interface with Link Access Procedure D-Channel (LAPD);
- interface with DSO-A circuits;
- interface with V.120;
- interface with cellular speech packetization networks and systems;
- signaling interfaces;
- Pulse Code Modulation (PCM)/Adaptive Differential Pulse Code Modulation (ADPCM); code switching for voiceband traffic;
- PCM encoding standards conversion.
- functional requirements, including
- build-out delay, echo control;
- congestion control strategy;
- maintenance and alarm functions;
- testing procedures.
- networking applications requirements, including
- procedures at intermediate cross-connect nodes, including congestion strategies;
- implementation and applications considerations.
PCME converts speech, voiceband data, facsimile, channel-associated (i.e., in-band) signaling, common-channel signaling, video, and digital data information from channelized DS1 or Synchronous Optical Network (SONET) formats to LAPD-like frame format. The LAPD-like frames are transported as packet streams in a wideband packet network over a full or fractional DS1, or a SONET virtual tributary.
Wideband packet technology, as used herein, refers to packet systems operating at 1.5 Mbit/s to 150 Mbit/s. To streamline processing and to limit delay so as to accommodate voice, voiceband data, facsimile and video, this technology uses a LAPD-like link layer protocol with unacknowledged operation and applicationspecific layer 3 protocols. Digital data transmission is supported by several layer 3 protocols, as explained in this document.
Wideband packet technology can be applied in public or private networks, virtual private networks, and satellite networks to achieve the following benefits:
- better utilization of long-haul digital lines by implementing low-bit-rate voice coding, silence elimination, and variable-bit-rate video coding;
- efficient sharing of the same network among voice, voiceband data, image, video, and data;
- automatic shifting of available transmission capacity between non-coincident traffic loads without time-of-day administrative procedures;
- tandem switch relief;
- automatic re-routing of traffic around failed links and nodes:
- uniform approach to dynamic load control and congestion control;
- common link testing procedures.