AT&T 3551 Switch User Manual


 
Configuring the Unit
5-293550-A2-GB20-10 February 1995
Table 5-14
Port Speed (External DBU) Configuration Options
Prt1( 9.6): 9.6
Next 64 56 48 28.8 19.2 14.4 9.6 4.8 2.4 1.2 Disab Prev
Port 1 Speed
. Primary data rate in kbps on Port 1. (Must be set to the same value in the
external
DBU.)
64 to Select to set the port’s operating rate.
1.2 kbps
Disab Select to disable the port.
Option Verification: For all ports, the DSU verifies that the sum of the individual port speeds does not exceed the
primary aggregate speed set in the
external
DBU’s
Rate(Kbps)
configuration option. If the sum of the port speeds equals
the primary aggregate rate,
an underspeed port selection is required
.
Prt2( 9.6): 9.6
Next 64 56 48 28.8 19.2 14.4 9.6 4.8 2.4 1.2 Disab Prev
Port 2 Speed
. Primary data rate in kbps on Port 2. (Must be set to the same value in the
external
DBU.)
64 to Select to set the port’s operating rate.
1.2 kbps
Disab Select to disable the port.
Option Verification: For all ports, the DSU verifies that the sum of the individual port speeds does not exceed the
primary aggregate speed set in the
external
DBU’s
Rate(Kbps)
configuration option. If the sum of the port speeds equals
the primary aggregate rate,
an underspeed port selection is required.
Underspeed: Disab
Next Disab Prt1 Prt2 Prev
Underspeed Port
. Selects which port is to run slightly underspeed to allow for in-band framing and in-band secondary
channel transport, if used. If more than one port is active and the sum of the port speeds equals the primary aggregate
speed,
then one synchronous port must run underspeed
.
The number of bits per second used for in-band framing is 10. The in-band secondary channel transport speed is set in
2nd Chan(bps)
and, if used, includes the 10 bps in-band framing. A port used for asynchronous operation may not be set
for underspeed.
NOTE: When
Port Cntrl
is set to DSD or
Share DevA
is enabled (in the
MUX (Setup)
option set), port speeds are only
counted once per DSD when calculating used bandwidth.
Disab Select if no port is to run underspeed during primary operation.
Prt1 or Select the port to run underspeed during primary operation.
Prt2