Enterasys Networks XSR-3020 - Manual (Page 101)

Cable, CompactFlash and Accessory Specifications
XSR Getting Started Guide A-15
T3/E3 NIM Card
The T3/E3 full and sub-rate NIM, as shown in Figure A-17 , is equipped with 1 Ethernet (WAN)
port that supports fractional T3/E3 transmission in un-channelized or clear channel mode with
BNC connectors. User data are encapsulated in HDLC packets before being sent to the line.
Figure A-17 1-Port T3/E3 NIM Card
Cables required for this NIM must be 75-ohm, DS3 Type 734 or 735 coaxial. DS3 cables support a
length up to 450 in length. E3 cabling supports a cable length up to 900 feet.
Un-channelized mode consists of the entire T3/E3 payload in one data path, but with T3/E3 framing
bits still in place. Only one HDLC channel is used. Throughput of the un-channelized link can be
limited by using only a portion of the entire payload. Various sub-rates are available to provide
compatibility with major DSU equipment suppliers. Scrambling may also be enabled as required
for DSU compatibility. Larscom zero suppression is supported.
Clear channel mode presents the board merely as the line driver for a link carrying HDLC packets
where even framing bits are used for data transfer. The T3/E3 framer operates in bypass mode
and renders the NIM a line driver. Both sides of the link must have the same setting to operate
correctly in this mode.
For more details on software configuration, refer to the XSR User’s Guide.
Regulatory/Safety Compliance
The T3/E3 NIM complies with the following regulatory requirements.
E3: FCC Class B, ITU-T G.703, G.704, G823 and TBR24 for world wide approval, National
Standards testing as required, and BABT Compliance United Kingdom directive 607114.
T3: FCC Class B, GR-499-CORE is the Bellcore test procedure that can be used for design
validation, JATE Green Book for Japan.
ALARM LOS
ENABLE LOF
Tx Rx
id