Translating between a switching format and a transport format

A packet switch operating method comprising:

• a packet switch assigning an Ethernet packet received on a port of the packet switch to a virtual switch based on the port and a first transport identifier comprised by the Ethernet packet;
• the packet switch adding a virtual switch identifier associated with the virtual switch to the Ethernet packet;
• the packet switch forwarding the Ethernet packet through a switching fabric of the packet switch to a destination interface of the packet switch, the destination interface being associated with the virtual switch;
• the packet switch receiving the Ethernet packet from the destination interface and then modifying the Ethernet packet to comprise a second transport identifier;
• the packet switch removing the virtual switch identifier from the Ethernet packet;
• and
• after removing the virtual switch identifier, the packet switch forwarding the modified Ethernet packet comprising the second transport identifier to a destination port of the packet switch associated with the destination interface.

A packet switch operating method comprising:

• parsing a packet received from an ingress port into one or more packet identifiers adapted to influence a forwarding decision;
• mapping the packet to a virtual switch based on the ingress port and a first subset of the packet identifiers, the virtual switch being associated with a plurality of ports;
• adding to the packet a virtual switch identifier associated with the virtual switch;
• if one of the plurality of ports is associated with a second subset of the packet identifiers, then forwarding the packet to that port;
• and
• if none of the ports of the plurality are associated with the second subset of the packet identifiers, then forwarding the packet to all of the ports of the plurality.