Configuring TCC Interface Switching
TCC joins disparate Layer 2 logical interfaces by means of a virtual Layer 2 switching technique.
Figure 30 illustrates Layer 2 TCC switching. In this example, Router A is connected by Frame Relay to Router B and Router B is connected by Fast Ethernet to Router C. Router B is a Juniper Networks router. TCC allows you to configure Router B to act as a multiservice Layer 2 switch. To do this, you configure a connection from Router A to Router C that passes through Router B. This effectively establishes Router B as a Frame Relay-to-Fast Ethernet switch and allows the router to switch frames transparently between Router A and Router C without regard to the frames' contents or the Layer 3 protocols. Router B removes the Frame Relay header from frames arriving on Datalink Connection Identifier (DLCI) 600 and adds an Ethernet header onto the frames before sending them to the Fast Ethernet link.
You can configure Layer 2 TCC switching on ATM, Cisco HDLC, Ethernet, Ethernet Extended VLAN, Frame Relay, and PPP circuits. TCC enables unlike interfaces to be connected with a single cross-connect.
To configure Layer 2 TCC switching, perform the following tasks on the router that is acting as the switch (Router B in Figure 30):
- Define the Encapsulation for Layer 2 TCC Switching
- Define the Connection for Layer 2 TCC Switching
- Configure MPLS
To view examples of Layer 2 TCC switching, see the following sections: