Cisco Field Manual[c] Router Configuration

• FDDI supports 100 Mbps data transfer rates using a token-passing scheme.

• A dual counter-rotating fiber- optic ring makes up an FDDI network.

• The total length of the fiber ring must be less than 200 km.

• A FDDI network can have up to 500 stations , separated by no more than 2 km (MMF) or 10 km (SMF).

• FDDI frames can contain from 17 to 4500 bytes.

• FDDI interfaces can act as either Single-Attach Stations (SASs) or Dual-Attach Stations (DASs)

Configuration

1. (Optional) Configure the ring scheduling:

   (interface) fddi token-rotation-time microseconds

   To vary the token's availability, the token rotation time can be set to microseconds (4000 to 165000 usec; the default is 5000 usec).

2. (Optional) Set the number of frames to transmit at one time:

   (interface) fddi frames-per-token number

   Each time the token rotates and is captured, a number of queued frames are transmitted to the ring. The number of frames can be from 1 to 10 (the default is 3).

Example

An FDDI interface is configured with IP and IPX addresses. It transmits up to eight frames per token.

interface fddi 4/0 description Server Farm FDDI ring ip address 10.1.1.1 255.255.255.0 ipx network 1234 fddi frames-per-token 8