Figure 13: 40-Port Sfp+ Line Card; Figure 14: Port Numbering And Port Groups On A 40-Port Sfp+ Line Card - Juniper EX8208 Complete Hardware Manual

Complete Hardware Guide for EX8208 Ethernet Switches
Line card LEDs
Ejector lever
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EX8200 switches use four types of line cards. You can use any combination of line cards
in an EX8200 switch.
The 40-port SFP+ line card for EX8200 switches (see Figure 13 on page 34) has 40
oversubscribed 10-gigabit SFP+ ports on the faceplate in which you can install SFP+
transceivers. Each port has two LEDs. See "Network Port LEDs in an EX8200 Switch" on
page 38. The ports are numbered sequentially (see Figure 14 on page 34). The ports are
divided into eight groups, each group comprising five ports (see Figure 14 on page 34).
The ports in each port group share 10 gigabits of bandwidth.

Figure 13: 40-port SFP+ Line Card

Network ports
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EX8 200- 40X S
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Figure 14: Port Numbering and Port Groups on a 40-port SFP+ Line Card

Group 0 Group 2
Group 1 Group 3
The port groups can have different oversubscription ratios depending on the number of
active ports in each port group. If only one port in a port group is active, the
oversubscription ratio is 1:1. If two ports are active, the ratio is 2:1; if all ports are active,
the ratio is 5:1.
If you transmit 10 gigabits of traffic through a port group, the line card does not drop
packets. However, if you transmit more than 10 gigabits of traffic through a port group,
the line card allows only a fair share of traffic to transit. For example, if you transmit 10
gigabits of traffic though each of the five ports in a port group, the line card allows only
a fifth of the traffic from each port to transit. If you transmit 10 gigabits of traffic though
two ports in a port group, the line card allows only half the traffic from each port to transit.
Because the port groups share bandwidth, class-of-service (CoS) ingress and egress
queues are handled differently on the 40-port SFP+ line card than on other line cards
for EX8200 switches (see Understanding CoS Queues on the 40-port SFP+ Line Card
on EX8200 Switches). As a result, the ports in a port group must use the same scheduler
map. By default, they use the default scheduler map. To configure a different scheduler
map on the ports in a port group, see Defining CoS Schedulers (CLI Procedure).
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Ejector lever Captive screw
Group 4 Group 6
Group 5 Group 7
Copyright © 2010, Juniper Networks, Inc.