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Configuration example, Configuration example -8, Bandwidth allocation example -8 – Cabletron Systems 1800 User Manual

Page 76

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7-8

SmartSwitch 1800 4. 0 User G uide, Rev 01

will be allocated 60/130 (46%) of the available bandwidth, and Group 2 will be allo-
cated 70/130 (54%).

Group "n" Excess Priority

determines the order in which groups are given their allocations of bandwidth; the
higher the number, the higher the priority.

Group "n" Use Excess Burst

will (if

Y

) allow traffic that falls into the Excess Burst Size to be transmitted. Any

packets exceeding B

E

will be buffered in the SmartSwitch.

Configuration Example

Here is an example of a typical bandwidth allocation group configuration:

This configuration ensures that SNA traffic, which is very time-sensitive, will be
given top priority, and will all be transmitted within the guaranteed 30% of the band-
width, eliminating the risk of discarded packets. Sequenced arrival of packets is not
critical among the first three groups, so those types of traffic can be configured to
allow transmission above the Committed Information Rate (CIR) (described on

page

7-18

). (Traffic above CIR is transmitted with the Discard Eligibility bit set, which

allows packets to be discarded if necessary.)

Table 7-2 Bandwidth Allocation Example

Group Used For

Percentage

Excess Priority Use Excess Burst

1

SNA

30

16

N

2

Logical Ports & Mgmt.

20

15

Y

3

IP

30

14

Y

4

IPX

20

13

Y