ZyXEL Communications GS 2200 Manual page 220

Chapter 27 Layer 2 Protocol Tunneling
To emulate a point-to-point topology between two customer switches at different sites, such as A
and B, you can enable protocol tunneling on edge switches 1 and 2 for PAgP (Port Aggregation
Protocol), LACP or UDLD (UniDirectional Link Detection).
Figure 140 L2PT Network Example
A
STP
27.1.2.1 Layer 2 Protocol Tunneling Mode
Each port can have two layer 2 protocol tunneling modes, Access and Tunnel.
• The Access port is an ingress port on the service provider's edge device (1 or 2 in
page 220) and connected to a customer switch (A or B). Incoming layer 2 protocol packets
received on an access port are encapsulated and forwarded to the tunnel ports.
• The Tunnel port is an egress port at the edge of the service provider's network and connected to
another service provider's switch. Incoming encapsulated layer 2 protocol packets received on a
tunnel port are decapsulated and sent to an access port.
220
STP
1
Service Provider's
Network
B
STP
2
C
GS2200-8/24 User's Guide
D
Figure 140 on