Chapter 3 System Features
DS3 IMA Module
3-50
255-700-025
PacketStar
™
Access Concentrator 60 User Guide
, Issue 1
Release 6.3.0
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FRF.2—Network-to-Network Interface (NNI)
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FRF.5—Frame Relay/ATM PVC Network Interworking
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FRF.8—Frame Relay/ATM PVC Service Interworking
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Multiservices:
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Frame relay UNI and NNI (FRF.1, FRF.2, FRF.5, and FRF.8)
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ITU-T I.370 (frame relay policing)
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Congestion management
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Traffic policing
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HDLC pass-through
Frame Relay
The DS3 Frame Relay module has interfaces for frame-relay network-level
interworking (FRF.5) and service-level interworking (FRF.8). A maximum of
350 permanent virtual circuits (PVCs) can be assigned on each frame relay
user-network interface (UNI) port. These features enable the Access
Concentrator system to act as a gateway between routers, remote dial-access
servers, IBM SNA equipment, and other devices configured for frame-relay
operation.
Frame relay policing, and user-selected point-to-point SVCs are supported on
the DS3 Frame Relay module. Frame relay policing enables the user to
manage traffic at the user-network interface (UNI) or network-network
interface (NNI) by setting performance parameters such as the Committed
Information Rate (CIR), Excess Burst size (Be), and Committed Burst size
(Bc).
HDLC Pass-through
Each port on the DS3 Frame Relay module can be configured to perform
adaptation for high-level data link control (HDLC) pass-through. Without
this feature, AAL-1 adaptation would be required for data from HDLC
devices connected to a port on the DS3 Frame Relay module. With this
feature, AAL-5 adaptation can be used to allow HDLC data to be handled as if
it were VBR rather than CBR. Since ATM cells are only generated when
HDLC is present, optimal bandwidth is used.
Hardware Features
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Number of ports: one
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Connector type: two BNC connectors for the single port which has one
receive connector and one transmit connector
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Line rate: 44.736 Mbps (typical)
DS3 IMA Module
The DS3 IMA (Inverse Multiplexing over ATM) module combines the
features of the Channelized DS3 module (see the
PacketStar
™
Channelized DS3