6
Speed
On the ENE2000-P (only), switches 1 and 2 control the port speed.
The E1 line has 31 channels continuously running at 64 kbps for a collective bandwidth
of 1,984 kbps. The timeslot configuration determines how many of the channels will
actually receive data. Ports configured to operate as fractional E1 lines require
contiguous timeslots as indicated in the table below.
Port 1 configuration switches 1 and 2 on the ENE2000-P work together to provide four
timeslot/bandwidth options for the Port 1 E1 link.
The ENE2000-S determines timeslot and bandwidth configuration for the E1 link via
communication with its partner E1 provider unit.
Frame Type
Switch 3 sets the Frame Type for the E1 port on both the ENE2000-P and the
ENE2000-S.
Frame type is the E1 data encapsulation method. A frame consists of 248 bits (8-bit
samples of each of the 31 E1 data channels plus a synchronization bit) transmitted at a
rate of 8,000 frames per second (1,984 kbps) across the E1 line. The ENE2000 can be
configured to use Cyclic Redundancy Check (CRC) to detect line errors and scrutinize
data integrity across the E1 line by appending a hexadecimal checksum (calculated
from the previous E1 frame contents) to the end of each E1 frame. The remote modem
then makes a similar calculation upon receipt of each E1 frame and compares it to the
checksum of the ensuing E1 frame.
Table 2. Speed Settings Using Switches 1 and 2
Switch 1
Switch 2
Timeslots
Bandwidth (kbps)
Down
Down
1–31
1,984
Up
Down
1–24
1,536
Down
Up
1–16
1,024
Up
Up
1–8
512
Table 3. Frame Type Settings Using Switch 3
Switch 3
Frame Type
Down
Cyclic Redundancy Check
Up
No Cyclic Redundancy Check
