Alcatel Carrier Internetworking Solutions Omni Switch/Router - Manual (Page 848)

The WAN Port Software Menu
Page 28-22
Speed in BPS
This option specifies the access rate for the Frame Relay or PPP line to the service provider.
This parameter is the speed of the entire connection, not an individual virtual circuit. For
example, if you have a 56 kbps line to your service provider, this field should be set to 56000.
A full T1 line would have an access rate of 1,544,000 bps, and a full E1 line would have an
access rate of 2,048,000 bps. For either T1 or E1, you can also have a fractional service with
an access rate that is a multiple of 64 kbps.
Enter a value that is the same as one of the values displayed below this field.
Note
If the port you are configuring is a physical DCE port
(i.e., DCE cable plugged into the submodule port) that
can control the access rate and clocking, always enter a
value for this field. This value will be used in
computing congestion control parameters, such as the
Committed Information Rate (CIR). If the port is a DTE,
this setting will have no effect, except for informational
purposes.
Clocking
This field sets the type of clocking used to clock transmit and receive data on the serial port.
If the clock goes out-of-phase, you will receive errors.
Note
The clocking value is only relevant if the port is a
physical
DCE port (i.e., DCE cable plugged into the
submodule port). If the submodule port is a physical
DTE port, clocking will default to External.
External Clocking
If you set this value to External, clocking will be controlled by the external DCE (a DSU or
other DCE device on the other end of the cable from the submodule port). External clock-
ing is the default option when the submodule is a physical DTE device (i.e., controlled by
an external DCE device).
When the submodule is acting as a physical DTE and
• the speed is greater than 256 kbps, or
• excessive FCS errors or Aborts are being detected coming from the submodule at the
remote port or line monitor
then it is recommended that the external DCE (usually a CSU/DSU) be set to take a trans-
mit data clock from the external DTE transmit clock (TXCE).