Cisco Systems 8600 Series manual BXM Trunk Egress Operation

BXM Functional Description

Egress

The egress flow of ATM cells out of the BXM when the card is configured for trunk operation is shown in Figure 6-12.

ATM cells are routed to the BXM 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 Demux/Mux (T3/E3). The SUNI or Demux/Mux, as applicable, processes the ATM cells into frames, processing the cells from the ATM layer to the physical and on out to the backcard trunk interface connecting to another node or network.

Figure 6-12		BXM Trunk 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

1.6Gbps Egress

from

BPX

Switching

Matrix

DRSIU

BPX

Fabric

Backplane

SIMBA

Ingress

Queue

Engine

QE

Engress

Queue

Engine

QE

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

622.08Node or

Mpbs	Network
1 or 2 port	via
	Trunk

Cell Memory

Q-Database

Stats Thresh

S6170

BXM T3/E3, 155, and 622 6-21