255-700-025
3-45
PacketStar
™
Access Concentrator 60 User Guide
, Issue 1
Release 6.3.0
Chapter 3 System Features
Channelized DS3 Module
Channelized DS3 Module
The Channelized DS3 module provides one port with a line rate of
44.736 Mbps. The user can configure this module to provide N x 64 Kbps
(fractional DS1) structured circuit emulation service. When configured for
DS1 circuit-emulation service, the module interfaces with TDM channelized
DS1 circuits. It converts the channelized digital signals (usually voice data) to
ATM virtual channels. By using structured (channelized) circuit emulation,
the Channelized DS3 module can adapt a maximum of 28 DS1 channels per
port to ATM virtual channels with individual VPIs and VCIs. Signaling bit
transport is also provided, using ATM Forum standards for channel-
associated signaling (CAS). This module can connect to a device using
56 Kbps or 64 Kbps for service transport, with 8 Kbps for robbed-bit signaling
per DS0. With the 64 Kbps "clear channel" capability, this module can
connect to a device using ISDN primary rate interface (PRI) service. Because
this structured circuit-emulation service can be configured to use only a
fraction of the time slots, the user can configure several independent
emulated circuits to share one service interface.
The Channelized DS3 module uses ATM Forum specifications UNI 3.0 or UNI
3.1, which allow any DS1 port to act as a user network interface (UNI), or an
interim inter-switch protocol (IISP) user or IISP network interface to an ATM
network.
With Release 6.3, the Channelized DS3 module supports activating and
deactivating DS1 access network interface (ANI) in-line loopback codes
embedded in the DS1 signal. These codes test transmissions between
customer interface equipment and network interface equipment, such as
between central office PSAX products and PSAX products at the edge of the
ATM network. The system also generates alarm indication signals on all
affected DS1 connections whenever a loop is activated.
Software Features
The following Frame Relay Forum (FRF) Implementation Agreements are
supported by the software:
•
FRF.1—User-to-Network Interface (UNI)
•
FRF.2—Network-to-Network Interface (NNI)
•
FRF.5—Frame Relay/ATM PVC Network Interworking
•
FRF.8—Frame Relay/ATM PVC Service Interworking
The following ATM Forum Technical Committee Specifications are supported
by the software:
•
Circuit Emulation Service Interoperability Specification Version 2.0
af-vtoa-
0078.00
•
User-to-Network Interface Specification Version 3.0
, af-uni.0010.001
•
User-to-Network Interface Specification Version 3.1
, af-uni.0010.002