232CHAPTER 8: FIBER DISTRIBUTED DATA INTERFACE (FDDI)

fddi path maxTreq

3500

9000

9400

3900

9300

Specifies the maximum time value (in microseconds) of fddiMACT-Req that is used by any MAC that is configured in this path. T-Req is the value that a MAC bids during the claim process to determine a ring’s operational token rotation time, T_Opr. The lowest T-Req bid on the ring becomes T_Opr.

Valid Minimum Abbreviation

fd pa m

Important Considerations

When you set T_Opr low, the token rotates more quickly, so token latency is reduced. However, more of the ring’s available bandwidth is used to circulate the token.

Higher values of T_Opr use less bandwidth to circulate the token, but they increase token latency when the ring is saturated.

You can use this command to configure the same setting on multiple ports simultaneously. When you specify multiple port numbers, the system prompts you to choose the setting and then applies it to all of the ports.

Options

Prompt

Description

Possible Values

[Default]

 

 

 

 

Ports

One or more FDDI station ports

Any of the

 

for which you want to set the

available ports

 

 

path maxTreq

on the installed

 

 

 

FDDI modules

 

Path

Path that you want to set.

 

A DAS port has primary and

 

 

secondary paths.

 

A SAS port has only a

 

 

primary path.

all

p (primary)

s (secondary)

all

maxTreq

Value that a MAC bids during

0 – 4294967295

16500

 

the claim process to determine

microseconds

 

 

a ring’s operational token

 

 

 

rotation time, T_Opr

 

 

 

 

 

 

Page 232
Image 232
3Com 3500 manual Fddi path maxTreq, Microseconds Ring’s operational token Rotation time, TOpr