Beta Draft Confidential
About ATM Logical Ports
About Logical Port Bandwidth
ATM Services Configuration Guide for CBX 3500, CBX 500, GX 550, and B-STDX 9000
1/19/05
2-17
In some cases, due to the way the switch stores logical port bandwidth, the NMS may
have to round down non-integer maximum logical port bandwidth values to the
nearest Kbps value.
Table 2-5.
Physical and Logical Port Bandwidth Conversions
Physical Port
Media Type
Physical
Port
Bandwidth
(Kbps)
Exact
Logical
Port
Bandwidth
(Kbps)
Exact
Logical
Port
Bandwidth
(cps)
NMS
Rounded
Maximum
Logical
Port
Bandwidth
(Kbps)
NMS
Rounded
Maximum
Logical
Port
Bandwidth
(cps)
OC-12c/STM-4
622080
599040
1412830.19
599040
1412830
OC-3c/STM-1
155520
149760
353207.55
149760
353207
OC-48c/STM-16
2488320
2396160
5651320.76
2396160
5651320
ATM DS3 (with
Physical Layer
Convergence
Protocol
[PLCP])
44736
40704
96000
40704
96000
ATM DS3 (with
header check
sequence [HCS]
direct mapping)
44736
44209.694
104268.15
44209
104266
ATM E3 (with
HCS direct
mapping)
34368
33920
80000
33920
80000
ATM E3 (with
G.751 PLCP)
34368
30528
72000
30528
72000
T1
1544
1536
3622.64
1536
3622
E1
2048
1920
4528.3
1920
4528
Note – For most applications, rounding down non-integer maximum logical port
bandwidth does not cause any problems. However, if you need to run 100% line rate
traffic through a policed PVC where you have rounded values, policing may cause
minor cell loss.
Summary of Contents for CBX 3500
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