Overview
2
Jabber Lock-up Protection.
Jabber lock-up protects the repeater
from being overrun with data packets from a possibly defective
device. That is, jabber lock-up automatically prevents transmitted
data from reaching the repeater if the transmitted data time exceeds
a specified duration (in the range of 20 to 150 ms).
Features
Network diagnostics are provided on the front panel of the AT-30xxTR
repeaters, as shown in Figure 1, 2 and 3, to aid in troubleshooting and fault
isolation. Each 10BASE-T network segment has two LEDs, packet “Receive”
and “Port OK.” In addition, there are three central LEDs indicating “Power,”
“Activity,” and “Collision” for the repeater as a whole, and a pair of LEDs
that show “Port OK” or “Receive” state for the AUI and BNC ports.
Each model includes switches that enable manual termination of the BNC
network port and internal signal crossover (MDI/MDI-X) on 10BASE-T Port
#1.
The CentreCOM Multiport Repeaters conform to the IEEE 802.3
specifications. This permits a maximum of four repeaters to be “cascaded”
through one of the 10BASE-T ports and enables up to 1024 individual
segments to be configured into a single network by the extended use of fan-
outs (see Chapter 7 for configuration diagrams).
Figure 1, 2 and 3 show the front panel layouts for the three AT-30xxTR
models:
Figure 1: AT-3012TR
Front Panel
1
2
3
4
5
6
7
8
9
10
11
12
X
X
X
X
X
X
X
X
X
X
X
ACTIVITY
COLLISION
POWER
1
2
3
4
5
6
7
8
9
10 11 12
1
2
3
4
5
6
7
8
9
10 11 12
TERMINATOR
OFF
ON
PORT OK
RECEIVING
PORT OK
RECEIVING
PORT OK
RECEIVING
POWER
10BASE-T NETWORK PORTS
10BASE-T PORT ACTIVITY
STATUS
AUI
BNC
1
2
3
6
1
2
3
6
1
2
3
6
1
2
3
6
MDI
MDI-X
IEEE 802.3
/ETHERNET
1
0BASE-
T
MUL
TIPORT REPEA
TER
Figure 2: AT-3016TR
Front Panel
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
TERMINATOR
OFF
ON
PORT OK
RECEIVING
PORT OK
RECEIVING
PORT OK
RECEIVING
POWER
10BASE-T NETWORK PORTS
STATUS
AUI
BNC
IEEE 802.3
/ETHERNET
1
0BASE-
T
MUL
TIPORT REPEA
TER
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
1
2
3
6
1
2
3
6
1
2
3
6
1
2
3
6
MDI
MDI-X
ACTIVITY
COLLISION
POWER
Figure 3: AT-3024TR
Front Panel
TERMINATOR
OFF
ON
PORT OK
RECEIVING
PORT OK
RECEIVING
PORT OK
RECEIVING
POWER
10BASE-T NETWORK PORTS
IEEE 802.3
/ETHERNET
1
0BASE-
T
MUL
TIPORT REPEA
TER
1
3
5
7
9
11
13
15
17
19
21
23
2
4
6
8
10
12
14
16
18
20
22
24
1
2
3
6
1
2
3
6
1
2
3
6
1
2
3
6
MDI
MDI-X
ACTIVITY
COLLISION
POWER
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
STATUS
AUI
BNC
1
3
5
7
9
11
13
15
17
19
21
23
2
4
6
8
10
12
14
16
18
20
22
24
