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LEDR Series I/O Guide
MDS 05-3627A01, Rev. D
14.3 Configurable Parameters
The following performance specifications of the T1 fractional interface
are adjustable by the user. All of these parameters are manageable
locally, or over the air via SNMP network management. (Refer to the
SNMP Handbook, P/N 05-3532A01 for more information.)
Timeslots and Framing
Twelve DS0 timeslots are permitted. In FT1, the timeslot selection is
arbitrary. In FE1, timeslot 0 is always sent and the remaining timeslots
are arbitrary with the exception of timeslot 16. (Timeslot 16 must be sent
when any CAS frame structures are selected.) The selection of timeslots
can be different at each end of the link, provided their number is equal.
The timeslots may not be reordered.
Alarm signals RAI and AIS are generated as appropriate. The user may
optionally have these signals forwarded over the RF link.
The frame formats available for Fractional-T1 operation are as follows:
• FT only
• ESF without CRC checking and generation
• SF (D4)
• SF with JYEL indication
• ESF with CRC checking and generation
The frame formats available for Fractional-E1 operation are as follows:
• FAS only
• FAS with BSLIP
• FAS with CRC
• FAS with CRC and BSLIP
• FAS and CAS
• FAS with CAS and BSLIP
• FAS with CAS and CRC
• FAS with CAS
• CRC and BSLIP.
The re-framing criteria may be adjusted to the following settings: 2 out
of 4 Fbit errors, 2 out of 5 Fbit errors, 2 out of 6 Fbit errors. For FE1, the
reframing criteria is selectable between consecutive FAS errors or CRC
errors.
Line Codes
The following standard T1 line codes are supported: B8ZS, AMI, and
per-channel B7ZS.
The following standard E1 line codes are supported: HDB3 and AMI.
