AAC / CellSMART Quad CBR/Packet Protocol Module
(2 packets/2 CBR ports; or 4 CBR ports)

General (Quad Packet/CBR)
Interface types supported

Frame-based interfaces, user-selectable:

Frame Relay UNI

ATM DXI/FUNI

/SMDS DXI

SMDX Kentrox Cisco Interface (obssolete)

HDLC frames (frame forwarding mode of operation)

Mates with these PLMs

Quad DSX-1

Quad E1

Tri V.35/EIA-530 & DSX-1/TRi V.35/EIA-530 & E1

Quad V.35/EIA-530

Processing capacity

2.048 Mbps per port

Services supported / modes of operation

SMDS over ATM via SMDS DXI or ATM DXI/FUNI (AAL3/4)

Frame Relay over ATM (AAL5)

Service or network interworking per VC via Frame Relay UNI

ATM DXI/FUNI (AAL5 and AAL 3/4)

HDLC Frame Forwarding (AAL5)

Connection (Quad Packet/CBR)
Number of virtual connections per port

SMDS DXI Mode: 1 VC with MID multiplexing capability, all traffic routed to a connectionless server over an ATM UNI or to another port with an SMDS interfae (AAL3/4)

HDLC Frame Forwarding Mode: 1 VC for all HDLC frames. All traffic routed to a single destination (channel extension) over an ATM UNI or to another HDLC port (AAL5)

Frame Relay UNI: 512 VCCs or DLCIs (AAl5)

ATM DXI: Maximum of 512 connections, of which up to 255 can be VPCs (AAL5 or AAL3/5)

Traffic and Congestion Management (Quad Packet/CBR)
Cell emission scheduling for minimal CDV

Per input port

General

Congestion management algorithm with partial packet discard and early packet discard and 4 VBR priorities.

Input queuing

Non-blocking input queue.

maximum burst size / burst tolerance

210 cells

Maximum CDV (CBR only)

250 microseconds per port (no assurance per connection)

Output queuing

VBR output queue, with traffic and congestion management capability

Rate control

SCR MAR rate control for CLP0+1, per VC.

Reassembly

Up to 18 simultaneous reassembly buffers of packets up to 9232 octets in length. User-selectable increase in number of simultaneous reassemblies to 36 with MTU reduced to 4616 octets.

Statistics Collection (Quad Packet/CBR)
Statistics collected per port

Number of valid cells (input and output)

Number of cells discarded for SCR violation

Number of cells discarded for congestion

Number of cells discarded due to corrupted AAL3/4 payload

Number of valid packets (input and output)

Number of packets discarded for invalid address (DLCI or DFA)

Number of discarded AAL5 CPCS_PDUs (CRC error after reassembly)

Number of packets discarded due to reassembly time-outs

Number of packets discarded due to unavailable reassembly buffer

Standards Compliance (Quad Packet/CBR)
Meets applicable requirements of the following standard/generic requirements

ATM Forum Contribution 94-0149, "protocol Interface Specification for Implementation of SMDS over an ATM Public UNI, " March 1994

Bellcore TR_TSV-000772, "Generic Requirements in Support of Switched Multi-Megabit Data Service, " May 1991

ATM Forum Contribution, ATMF 94-0996, "Frame Relay/ATM PVC Service Interworking Implementation Agreement"

Bellcore GR-1113-COR, "Asynchrnous Transfer Mode (ATM) and ATM Adaptation Layer (AAL) Protocols Generic Requirements, " July 1994

Bellcore GR-2842-CORE, "ATM Service Access Multiplexer (SAM) Generic Requirements, " November 1994

Bellcore TA-NWT-001110, "Broadband ISDN Switching System Generic Requirements, " August 1992.

ITU-T Recommendation 1.311, "Broadband ISDN General Aspects"

ITU-T Recommendation 1.150, "Asynchronous Transfer Mode Functional Characteristic."

ITU-T Recommendation 1.361, "Broadband ISDN ATM Layer Specification."

ITU-T Recommendation 1.363, "Broadband ISDN Adaptation Layer Specification."

ITU-T Recommendation 1.364, "Support of Broadband Connectionless Data Service on B-ISDN."

ITU-T REcommendation 1.555, "Frame Relaying Bearer Service Interworking"

ITU-T Recommendation 1.371, "Traffic Control and Congestion Control in B-ISDN."

General (CBR)
Interface types supported

Serial constant bit rate

Processing capacity

2.048 Mbps (4528.3 cells/second) per port

Services supported / modes of operation

CBR CES, structured or unstructed mode (AAL1)

supports structured or unstructured interoperability between V.35 CBR and DSX-1 or E1 CBR

Connections (CBR)
Number of virtual connections per port

One active connection at a time.

Traffic and Congestion Management (CBR)
Cell emission scheduling for minimal CDV

Per connection (one connection per port)

General

No congestion management. Congestion may occur only due to misallocating bandwidth. This result in cell discard and an immediate alarm.

Input queueing

Non-blocking input queue

maximum CDV

250 microseconds

Output queuing/reassembly

One reassembly output queue with user-controllable depth

depth influences CDVT (higher depth = higher CDVT)

Six cell reassembly latency (Latency is a one-time delay introduced at the activation of the connection).

User-selectable queue depth of 12 to 21 cells in 3-cell steps.

Statistics Collection (CBR)
Statistics collected per port

Number of received valid cells

Number of cells discarded due to corrupted AAL1 header.

Number of cells discarded or missing due to mis-sequencing (non-contiguous sequence number in contiguous cells)

Standards Compliance (CBR)
Meets applicable requirements of the following standards/generic requirements

ATM Forum AF-SAA-0032 000, "Circuit Emulation Service Interoperability Specification, " Une 1995.

ATM Forum AF-VTOA-0078.000, "Circuit Emulation Service Interoperability Specification Version 2.0, " November 1996.

Bellcore GR-1113-CORE, "Asynchornous Transfer Mode (ATM) and ATM Adaptation Layer (AAL) protocols Generic Requirements, " July 1994

Belcore GR2842-CORE, "ATM Service Access Multiplexer (SAM) Generic Requirements, " November 1994.

Bellcore TA-NWT-001110, "Broadband ISDN Switching System Generic Requirements, " August 1992.

ITU-T REcommendation 1.311, "Broadband ISDN General Aspects"

ITU-T Recommendation 1.150, "Asynchronous Transfer Mode Functional Characteristc."

ITU-T Recommendation 1.361, "Broadband ISDN ATM Layer Specification."

ITU-T Recommendation 1.363.1, "Broadband ISDN Adaptation Layer Specification."

ITU-T Recommendation 1.371, "Traffic Control and Congestion Control in B-ISDN."

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