Juniper Networks EX8208 Switch User Manual


 
48-port SFP line card
48-port RJ-45 line card
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 32) has 40
oversubscribed 10-gigabit SFP+ ports on the faceplate in which you can install either
SFP+orSFPtransceivers.EachporthastwoLEDs.See“NetworkPortLEDsinanEX8200
Switch” on page 37. The ports are numbered sequentially (see Figure 14 on page 32).
The ports are divided into eight groups, each group comprising five ports (see Figure 14
on page 32). The ports in each port group share 10 gigabits of bandwidth.
Figure 13: 40-port SFP+ Line Card
20 21 22 23 24
25 26 27 28 29
10 11 12 13 14
15 16 17 18 19
0 1 2 3 4
5 6 7 8 9
30 31 32 33 34
35 36 37 38 39
EX8200-40XS
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Line card LEDs
Ejector lever
Ejector lever
Network ports
Captive screw
Figure 14: Port Numbering and Port Groups on a 40-port SFP+ Line Card
Group 0 Group2 Group 4 Group 6
Group 1 Group 3 Group 5 Group 7
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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
twoportsinaportgroup,thelinecardallowsonlyhalfthetrafficfromeachporttotransit.
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
onEX8200 Switches).Asa result,the ports ina portgroup mustuse thesame 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).
Copyright ©2010,Juniper Networks,Inc.32
CompleteHardwareGuide forEX8208 EthernetSwitches