Cisco CRS-1 - Carrier Routing System Router Troubleshooting Manual page 122

CRS-1 Switch Fabric Overview
Figure 4-1 Cisco CRS-1 Architecture
Packets
Between ingress queue, S1, S2, S3, and fabric queue ASICs are communication paths known as fabric
links. An individual fabric link has a bandwidth capacity of 2.5 Gbps. A link is unidirectional.
An ingress MSC has multiple 2.5 Gbps links from the ingress queue ASIC on the MSC to an individual
fabric plane and to an individual S1 ASIC on that fabric plane. Connections are provided in the same
fashion to each of the eight fabric planes that are present in a system in normal operation.
All S1 ASICs have at least one 2.5 Gbps link to every S2 ASIC present on that fabric plane. An S1-to-S2
link does not and cannot span across fabric planes.
All S2 ASICs have at least one 2.5 Gbps link to every S3 ASIC present on that fabric plane. An S2-to-S3
link does not and cannot span across fabric planes.
An egress MSC has multiple 2.5 Gbps links from the S3 ASIC to one or two fabric queue ASICs present
on that MSC.
In a 16-slot single-chassis system, the eight switch fabric planes are contained on eight individual fabric
cards known as FC/S or S123. Each of the fabric cards contains two S1, two S2, and four S3 ASICs.
In an 8-slot system, the eight switch fabric planes are contained on four individual fabric cards known
as FC/S or HS123. Each fabric card contains two planes. Each plane is composed of one S1, one S2, and
one S3 ASIC.
In a 4-slot system, there are four fabric planes. The fabric planes are contained on four individual fabric
cards known as FC/s or QS123. Each plane is composed of one S1, one S2, and one S3 ASIC.
Each S13 card contains two S1 and four S3 ASICs and corresponds to one switch fabric plane. Each
fabric card chassis has one or more switch fabric planes and each fabric plane consists of one or more
S2 fabric cards. Each S2 fabric card contains six S2 ASICs.
Cisco IOS XR Troubleshooting Guide for the Cisco CRS-1 Router
4-112
RP (standby)
Statistic packets
for the platform
M
PLIM MSC
I
D
PLIM MSC
P
L
PLIM MSC
A
N
PLIM MSC
E
in
PLIM M MSC
I
D
PLIM MSC
P
L
PLIM MSC
A
N
PLIM MSC
E
Chapter 4
RP (active)
CEF tables and
routing packets
F F
M
A A
I
D B B
P
R R
L
I I
F
A
C C
A
N
B
S1 S3
E
R
I
F F
M C
A A
I
S2
D B B
P
R R
L
I I
A
C C
N
S1 S3
E
Troubleshooting Router Switch Fabric
Statistic packets
for the platform
M M
MSC PLIM
I I
D D
MSC PLIM
P P
L L
MSC PLIM
A A
N N
MSC PLIM
E E
M MSC M PLIM
I I
D D
MSC PLIM
P P
L L
MSC PLIM
A A
N N
MSC PLIM
E E
Packets
out
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