Legacy Data System Reference - Comtech EF Data

Legacy Data
4.1 Support of PASSTHRU over Frame Relay
PASSTHRU over Frame Relay (PASSTHRUOFR), can be defined on a serial port or
digital channel for data transport over Frame Relay multicast.
• This protocol is used for multicast applications requiring transport of any type of
incoming traffic to several remote sites via a Frame Relay network.
• One application for PASSTHRUOFR is to carry radar information from one
emitter to several receptors/monitors as illustrated in the figure below.
NOTE: PASSTHRUOFR on a digital T1 or E1 channel is supported on the SDM-
9220 and SDM-9230 only.
Figure 4-1: PASSTHRU over Frame Relay Application
On the NetPerformer, a serial port or digital PASSTHRUOFR channel serves as the
Network Port of a TRANSP PVC, as shown in the example application above. The
PASSTHRUOFR connection operates as follows:
• A frame of any type is received at the PASSTHRUOFR port (radar traffic, in the
example above)
• The NetPerformer encapsulates the payload in a Frame Relay frame structure
• The encapsulated frame is sent to another unit capable of handling Frame Relay
multicast transmissions
• Several remote stations can receive the frames, according to the specific Network
DLCI.
4-2 Memotec Inc.