3Com 3C421600A, Management Manual

Page: 143 / 300

Configuring Link Option Settings
141
Setting the Lowest Possible Connect Speed
The &U command allows you to set the lowest possible connect speed.
When a remote modem connects to an RAS 1500, it limits the minimum
speed of the connection based on the value specified with &U. If the &U
argument is zero, the connection is limited to the single speed implied by
the &N argument.
Setting a Range of Possible Connect Speeds
By setting &N and &U values, you can control the range of speeds at
which an RAS 1500 connects with remote modems. When a remote
modem connects to an RAS 1500, it limits the range of speeds of the
connection based on the value specified with &U and &N. If the &U
argument is zero, the connection is limited to the single speed implied by
the &N argument.
For asymmetrical links, &N and &U are used to constrain the speed of the
higher speed direction of the link. The speed of the lower speed direction
is constrained by values given in S registers.
If the link speed associated with the &U argument is greater than the link
speed associated with the &N argument, the RAS1500 treats the &U
argument as if it were zero and limits the connection to a single speed.
Use Table 35 to understand the relationship between &U and &N
commands:
Table 35 Connect Speeds
IF &U and &N Modem Action
Equals zero Equals zero Connects at the highest possible
speed.
Equals zero Is greater than zero Connects at the &N speed only.
Is greater than zero Is greater than zero
and greater than &U Connects at the highest possible
speed in the range from &U to &N.