Cisco Systems 8600 Series manual BXM Port Access, UNI Egress Operation

BXM Functional Description

Egress

The egress flow of ATM cells out of the BXM when the card is configured for port (access) operation is shown in Figure 6-10.

ATM cells are routed to the BXM-622 via the BPX Backplane/Stratabus from the BPX crosspoint switch, applied to the DRSIU, then to an egress queue per class of service, and then served out to the SUNI (OC3/OC12) or Mux/Demux (T3/E3) which processes the ATM cells into frames, processing the cells from the ATM layer to the physical and on out to the CPE connected to the port(s) on the BXM backcard. For ABR cells, additional functions are performed by the SABRE ABR connection controller, including: VS/VD, Foresight, and virtual connection queueing.

Figure 6-10 BXM Port (Access, UNI) Egress Operation

SABRE	Scheduling and ABR Engine	SUNI	SONET/SDH UNI ASIC
SIMBA	Serial I/F and Multicast Buffer ASIC	ACP	Sub-system Processor
RCMP	Routing Ctl, Monitoring, & Policing ASIC	ASIC	Application Specific Integrated Ckt
DRSIU	Dual Receiver Serial I/F Unit

Control/Admin Processor

(ACP)

Cell Memory Q-Database Stats Thresh

BPX

Backplane/

StrataBus

800Mbps

Ingress to BPX

Switching

Matrix

1.6 Gbps

DRSIU

BPX

Fabric

Backplane

SIMBA

Ingress

Queue

Engine

QE

ABR

Connection

Controller

SABRE

ABR

Connection

Controller

SABRE

RCMP

Route

Control,

Monitoring,

Traffic

Policing

SUNI

for

OC3

or

OC12

or Mux/ Demux for T3/E3

Back

Card

T3/E3

8 or 12 port

or

OC155.52

Mbps 4 or 8

port

or

OC12

To

622.08

Egress

Mpbs

UNI

from

BPX

Switching

Matrix

Engress

Queue

Engine

QE

1 or 2 port

CPE

Cell Memory

Q-Database

Stats Thresh

S6168

BXM T3/E3, 155, and 622 6-19