Cabletron Systems FRM User Manual - Chapter 7
Chapter 7
Configuring Frame Relay
Introduction
Frame relay ports in the FRM are used to carry frame relay traffic, as well as other
protocols encapsulated in frame relay (per RFC 1490, via logical X.25 ports over
frame relay). A frame relay port can act as physical DCE, connecting to end-user
devices, or DTE, connecting to a network or frame relay PVC.
Frame relay support includes:
●
RFC 1490 for HDLC, IP, IPX over frame relay
●
Line speeds up to 2.048 Mbps
●
LMI, Annex D link management
●
Annex F segmentation and re-assembly
●
Bandwidth allocation
●
Connection prioritization
●
Incoming and outgoing rate control (CIR)
●
Virtual circuit backup for single or multiple PVCs/DLCIs, including bandwidth
allocation on backup circuits
A frame relay port can contain up to 56 logical ports per RLP. All 56 logical ports can
reside on one physical port, or be spread over several physical ports.
DLCI Sharing
Each logical connection on a physical frame relay port is assigned a Data Link Con-
nection Identifier (DLCI), which identifies a point-to-point connection, as shown in
the following example. (The numbers represent DLCIs.)
Multiple protocols can be passed over a single physical frame relay port by sharing a
DLCI. Each node supports up to 976 user-configurable DLCIs. (Several more are sup-
ported, but are reserved for internal use.)
31
20
20
16
16
25