Siemens SIMATIC NET SCALANCE M826 Operating Instructions Manual page 50

Connecting up
4.5 DSL connection
SHDSL speed [Kb/s]
2048
2304
2688
3072
3456
3840
4224
4608
4992
5376
5696
6144
6656
7168
7680
8192
8704
9216
9728
10240
10752
11264
11776
12288
13056
13824
14592
15232
The path costs to the root bridge are added from the port to port path costs from the bridge
to the root bridge.
Port role and port status
The port role and port status are only negotiated when the SHDSL connection is actually
established.
Note that the ring topology becomes unstable if the SHDSL connection speed is below 384
kbps. If the SHDSL connection is overloaded, a hello frame may arrive too late causing a
constant topology change.
50
Path cost
9765625
8680555
7440476
6510417
5787036
5208333
4734848
4340277
4006410
3720238
3511236
3255208
3004807
2790178
2604166
2441406
2297794
2170138
2055921
1953125
1860119
1775568
1698369
1627604
1532802
1447597
1371365
1313715
Operating Instructions, 08/2018, C79000-G8976-C362-05
SCALANCE M826