East Coast Datacom Nx8- Dual Composite MUX High-Speed 16-Port TDM..., Operation Manual

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8/31/2006 26
Table 11
1 -5-
6
16
32
2
-2-
-2-
48
8
-7-
128
4
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
hs hf ls lf
1
-12-
-32-
-16-
8
4
3
5
-64-
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
hs hf ls lf
316
4
fail
0
LINK A: total user timeslots
remaining free timeslots
LINK B: total user timeslots
remaining free timeslots
-32-
-16-
8
4
3
5
-72-
-32-
-24-
8
4
3
5
-18-
8
4
3
5
12
6
12
12
downspeed
-5-
16
32
2
-12-
-12-
48
8
-7-
128
18
-6-
16
32
18
48
8
7
128
16
18
48
8
7
128
24
96/24
24
12
96/24
The system proceeds to scan the low-priority channels seeking backup in the next step. The
first one, channel 2 has a failover rate requiring 6 timeslots. There are 10 timeslots left over
from the previous step, which is sufficient. Therefore, channel 2 is reallocated, leaving 4
unused timeslots.
Table 12
blocked,
insufficient BW
1 -5-
2
16
32
2
-2-
-2-
48
8
-7-
128
4
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
hs hf ls lf
1
-8-
-32-
-16-
8
4
3
5
-64-
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
hs hf ls lf
316
4
fail
0
LINK A: total user timeslots
remaining free timeslots
LINK B: total user timeslots
remaining free timeslots
-12-
-32-
-16-
8
4
3
5
-64-
-32-
-16-
8
4
3
5
-72-
-32-
-24-
8
4
3
5
-18-
8
4
3
5
12
6
12
12
-5-
6
16
32
2
-2-
-2-
48
8
-7-
128
4
-5-
16
32
2
-12-
-12-
48
8
-7-
128
18
-6-
16
32
18
48
8
7
128
16
18
48
8
7
128
24
96/24
24
12
96/24
In the final step, the system attempts to find bandwidth on Link A for channel 11, the
remaining low-priority channel seeking backup. With only 4 timeslots free, and it‟s inability to
bump any other channels, channel 11 is blocked from reallocation to Link A.
The blocking of a channel backup due to link failure can be the result of a miscalculation in
planning. Although all other channels backed up will operate as expected on the surviving
link, without any other changes to port and link rates, channel 11 will not. As such, it should
have been coded as low-priority, fixed (lf) since it will never get the opportunity to be backed
up without manual intervention.
It should be apparent that the user responsible for network planning will need to consider
each link failure scenario in order to avoid situations like that above. It cannot be assumed
that simply because a channel is set to seek bandwidth, even if it is high-priority, that it will be
backed up in the event of a link failure. Given the flexibility in channel failover settings,