Cisco Systems IGX 8400 Manual De Usuario
Trunk Cards 4-11
Universal Switching Module Enhanced
The card-based default and maximum cellbus bandwidth for each interface appears in Table 4-5.
Note that FastPackets require substantially less cellbus bandwidth than ATM cells. The FastPacket
requirements in the figure and table reflect the restriction of FastPackets to one lane and the
maximum processing rate of the gateway on the UXM-E.
Note that FastPackets require substantially less cellbus bandwidth than ATM cells. The FastPacket
requirements in the figure and table reflect the restriction of FastPackets to one lane and the
maximum processing rate of the gateway on the UXM-E.
The values you can view with the cnfbusbw and dspbusbw commands are:
•
Minimum Required Bandwidth, the necessary bandwidth that switch software has calculated for
the existing connections on the local UXM-E. The display shows the requirements for
FastPackets, ATM cells, and the equivalent in total UBUs.
the existing connections on the local UXM-E. The display shows the requirements for
FastPackets, ATM cells, and the equivalent in total UBUs.
•
Average Used Bandwidth is the average bandwidth usage.
•
Peak Used Bandwidth is the peak bandwidth usage.
•
Maximum Port Bandwidth is the maximum bandwidth that the back card can support. The
FastPackets per second field has a dash-mark because only cells pass through the port.
FastPackets per second field has a dash-mark because only cells pass through the port.
•
Allocated Bandwidth is the current cellbus allocation for the card. The field shows the UBUs, the
bandwidth when only ATM cells are on the bus, and cells plus Fastpackets. The reason for cells
alone and cells plus Fastpackets is that cells can exist on the cellbus with or without FastPackets.
The last field under Allocated Bandwidth shows the formula to which the allocated values must
adhere. (A description of the formula follows the example screen.)
bandwidth when only ATM cells are on the bus, and cells plus Fastpackets. The reason for cells
alone and cells plus Fastpackets is that cells can exist on the cellbus with or without FastPackets.
The last field under Allocated Bandwidth shows the formula to which the allocated values must
adhere. (A description of the formula follows the example screen.)
Table 4-6
Cellbus Bandwidth Allocation for UXM-E Interfaces
Planning for Cellbus Bandwidth Allocation
With the Network Modeling Tool™ (NMT), you can use the projected load for all UXM-Es in the
network to estimate their cellbus requirements. During normal operation, you can use Cisco WAN
Manager to obtain the trunk and port statistics then decide whether to use cnfbusbw to increase the
UBU allocation. If you are using only the CLI, you would need to establish a virtual terminal (vt)
session to each node then execute dspbusbw or cnfbusbw.
network to estimate their cellbus requirements. During normal operation, you can use Cisco WAN
Manager to obtain the trunk and port statistics then decide whether to use cnfbusbw to increase the
UBU allocation. If you are using only the CLI, you would need to establish a virtual terminal (vt)
session to each node then execute dspbusbw or cnfbusbw.
Inter-
face
Type
face
Type
Ports
Default
UBUs
UBUs
Default
Cell
Traffic
Only
(cps)
Cell
Traffic
Only
(cps)
Default
Cell + Fpkt
Traffic
(cps and fps)
Cell + Fpkt
Traffic
(cps and fps)
Max.
UBUs
UBUs
Max.
Cell
Traffic
Only
(cps)
Cell
Traffic
Only
(cps)
Maximum
Cell + Fpkts
Traffic
(cps and fps)
Cell + Fpkts
Traffic
(cps and fps)
OC3
4 or 2
44
176,000
132,000, 88,000
235
708,000
473,000, 470,000
T3
6 or 3
24
96,000
72,000, 48,000
235
708,000
473,000, 470,000
E3
6 or 3
20
80,000
60,000, 40,000
235
708,000
473,000, 470,000
T1
8
8
32,000
24,000, 16,000
32
128,000
96,000, 64,000
T1
4
4
16,000
12,000, 8,000
16
64,000
48,000, 32,000
E1
8
10
40,000
30,000, 20,000
40
160,000
120,000, 80,000
E1
4
5
20,000
15,000, 10,000
20
80,000
60,000, 40,000