The Source Routing Configuration Window 3-31
Using the TSX-1620 Bridge View
descriptors (bridge hops) allowed in a packet’s Routing Information Field. A
bridge port will discard any explorer packets whose RIF’s exceed the maximum
number of routing descriptors.
Local Segment Number
Normally, when assigning local segment numbers, you must assign a unique
number to each network segment in a network; this field represents the network
segment to which this port is attached physically. The bridge adds the Local
Segment number to the routing information field of source route discovery
frames. Valid entries range from 0 to 4095. A value of 65535 indicates that no
segment number is assigned to this port. For the TSX-1620, you can assign the
same local segment number to separate physical rings attached to multiple ports
on the TSX-1620, and the device will treat them as if they were a single ring. For
each separate local segment number defined for the TSX-1620’s ports, a separate
Bridge Port box will be displayed in the Bridge View.
Bridge Number
A Bridge Number uniquely identifies this bridge port when two bridge ports are
used to span the same two segments; otherwise unique Bridge Numbers are not
necessary for individual ports. The Bridge Number should be in the range of 0 to
15. The value 65535 indicates that no Bridge Number is assigned.
Target Segment Number
The unique network number of the target network segment that the bridge
attaches to. Valid entries range from 0 to 4095. A value of 65535 indicates that no
target segment number is assigned to this port. Individual ports on a TSX-1620
should each be assigned unique values for this field.
Largest Frame
The maximum size of a frame’s INFO field that this port can send or receive. The
default value for this field is set in the TSX-1620’s firmware. When it receives an
explorer frame, the bridge uses its Largest Frame value to decide if it should
modify the Routing Control field of the Routing Information field. A Source Route
bridge has the ability to embed this information into the explorer packets so that
end stations can adjust their Mtu size accordingly.
Possible Largest Frame sizes as defined by the 802.5 source routing bridging
specification are 516, 1500, 2052, 4472, 8144, 11407, 17800, and 65535.
NOTE
The TSX-1620 does not use the Target Segment Number field because it has more than
two ports and therefore could have multiple target segments for each local segment.