Cisco CAtalyst 4500 Series Installation Manual page 68

System Architecture
Figure 1-23 Switching Traffic Flow
6 Gbps up / 6 Gbps down
MUX
6 Gbps up / 6 Gbps down
Over-subscription
Catalyst 4500 Series Switches Installation Guide
1-50
1000BASE-T 8:1
(oversubscribed)
1000BASE-T 1:1
Frames flow into the switch through interfaces on the switching modules. Each
switching module connects to a mux/buffer on the backplane that supports a
connection of up to 6 Gbps up (Tx) to the supervisor engine and 6 Gbps from (Rx)
the supervisor engine. When a frame reaches the supervisor engine, it is examined
and either sent out of an interface in one of the other slots, or out of the uplink on
the supervisor engine.
Switching modules that have 24 or 48 Gigabit Ethernet (1000BASE-T) ports
over-subscribe on a Catalyst 4500 switch by grouping the ports with an additional
mux/buffer on the switching module, which creates a single, nonblocking,
full-duplex Gigabit Ethernet connection to the internal switch fabric. For each
group of ports, frames received are buffered and sent to the common Gigabit
MUX
24 Gbps
(Supervisor Engine)
Clock
Chapter 1 Product Overview
2 Gigabit Ethernet
uplinks
78-14409-08