Function And Operation Of The Fabric Cards - Nortel Passport 15000 Hardware Description

Table 11
The features of a 70 Gbits/s fabric
Feature
throughput capacity
port configuration
base speed per port
self routing
multicast, broadcast
flow control
shared memory depth
QoS support
DASL interface
Unilink interface
JTAG
technology

Function and operation of the fabric cards

The fabric cards provide the shelf with two redundant 16x16 switching
elements for interconnecting up to 16 processor cards. Both fabrics balance
and load-share traffic. Each one operates at about half capacity so that it can
take over the traffic of its mate. Either fabric can handle all traffic carried by
a fully provisioned and configured Passport 15000 or 20000 switch.
Under normal operation, each processor card transmits to and receives from
half the processors on the upper fabric (the X fabric in software) and half on
the lower fabric (the Y fabric). When the control processor (CP) detects a
fault in a fabric, or when the fabric is manually locked, the CP blocks all new
Description
112.6 Gbits/s (70 Gbits/s shelf capacity) from 2
fabrics each with 70 Gbits/s operating at half
capacity in load-sharing (redundant) mode for a
total shelf capacity of 70 Gbits/s
16 x 16 non-blocking
4.0 Gbits/s and 16.0 Gbits/s for the four slots when
10 G cards are installed
yes
yes
grant
256 or 512 cells
Passport 20000 uses 2 priorities
3.52 Gbits/s
16 Gbits/s
yes
CMOS5S6, 0.35 Um
Passport 15000, 20000 Hardware Description
Chapter 3 Shelf assembly 101
5.2S2