Editing Wormhole switching (section)

=== Source routing ===
{{Main | source routing }}

With source routing, the packet sender chooses how the packet is routed through the switch.

If the first byte of an incoming SpaceWire packet is in the range 1 to 31,
it indicates the corresponding port 1 to 31 of the Spacewire switch.
The SpaceWire switch then discards that routing character and sends the rest of the packet out that port.
This exposes the next byte of the original packet to the next SpaceWire switch.
The packet sender may choose to use [[source routing]] to explicitly specify the complete path through the network to the final destination in this fashion.<ref name="Cook-Walker" />