Juniper Networks EX8208 manual port SFP+ Line Card

Complete Hardware Guide for EX8208 Ethernet Switches

•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+ or SFP transceivers. Each port has two LEDs. See “Network Port LEDs in an EX8200 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

Network ports

Line card LEDs

0	1	2
5			3	4
	6	7
			8	9

EX8200-40XS

Ejector lever

10	11	12
15			13	14
	16	17
			18	19

20	21	22	23
25	26			24
		27	28
				29

30	31	32	33
35	36			34
		37	38
				39

Ejector lever Captive screw

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Figure 14: Port Numbering and Port Groups on a 40-port SFP+ Line Card

Group 0 Group 2 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 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).

32 Copyright © 2010, Juniper Networks, Inc.