Nortel 450-24t 用户指南
Using the BayStack 450 10/100/1000 Series Switch
B-4
309978-D Rev 01
1000BASE-LX Models
The 450-1LX and 450-1LR MDAs provide 1000BASE-LX (1300 nanometers,
long wavelength, Gigabit Ethernet) connectivity. The 450-1LX provides one
1000BASE-LX port. The 450-1LR provides one 1000BASE-LX port and one
LinkSafe redundant port.
long wavelength, Gigabit Ethernet) connectivity. The 450-1LX provides one
1000BASE-LX port. The 450-1LR provides one 1000BASE-LX port and one
LinkSafe redundant port.
Operating Range
Table B-5 lists the operating range for the 1000BASE-LX models:
Table B-4.
Worst-Case 1000BASE-SX Power Budget and Penalties
Parameter
62.5 Micron
Multimode Fiber
Multimode Fiber
50 Micron
Multimode Fiber
Multimode Fiber
Units
Modal bandwidth as measured at 850 nm
(minimum, overfilled launch)
(minimum, overfilled launch)
160
200
400
500
MHz · km
Link power budget
7.5
7.5
7.5
7.5
dB
Operating distance
220
275
500
550
m
Channel insertion loss *, †
2.38
2.60
3.37
3.56
dB
Link power penalties
4.27
4.29
4.07
3.57
dB
Unallocated margin in link power budget
0.84
0.60
0.05
0.37
dB
* Operating distances used to calculate the channel insertion loss are the maximum values specified in Table B-1 on
† A wavelength of 830 nm is used to calculate channel insertion loss, link power penalties, and unallocated margin.
Table B-5.
Operating Range for 1000BASE-LX
Fiber Type
Modal Bandwidth @ 1300 Nanometers with
Minimum Overfilled Launch (MHz · km)
Minimum Overfilled Launch (MHz · km)
Minimum Range (Meters)
62.5 um MMF
500
2 to 550
50 um MMF
400
2 to 550
50 um MMF
500
2 to 550
10 um SMF
N/A
2 to 5000