AI2524 Router Card User’s Manual
Page 4-14 August 1997
2524UM
transmitter-delay Set dead-time after transmitting a datagram
tunnel protocol-over-protocol tunneling
tx-queue-limit Configure card level transmit queue limit
vines Vines interface subcommands
xns XNS interface subcommands
Subinterface Configuration Mode Commands
You can configure multiple virtual interfaces (called subinterfaces) on
a single physical interface. This feature is supported on serial inter
faces with Frame Relay encapsulation.
Subinterfaces appear to be distinct physical interfaces to the various
protocols. For example, Frame Relay networks provide multiple point-
to-point links called permanent virtual circuits (PVCs). PVCs can be
grouped under separate subinterfaces that in turn are configured on a
single physical interface. From a bridging spanning-tree viewpoint,
each subinterface is a separate bridge port, and a frame arriving on one
subinterface can be sent out on another subinterface.
Subinterfaces also allow multiple encapsulations for a protocol on a
single interface. For example, a router or acc ess server can receive an
ARPA-framed internet packet exchange (IPX) packet and forward the
packet back out the same physical int er fa ce as a Subnetwork Access
Protocol (SNAP)-framed IPX packet. The subinterfaces can be config-
ured to support multiple Frame Relay PVCs.
In this example, a subinterface is configured for serial line 2, which is
configured for Frame Relay encapsulation. The subinterface is called
2.1 to indicate that it is subinterface 1 of serial interface 2.