| |
Private line networks permanently allocate dedicated transmission resources between communications end points, regardless of traffic conditions. The frame relay network uses statistical multiplexing; therefore, transmission resources are not allocated until active communications exist. Network resources are shared dynamically among participating end points.
Frame relay networks provide the best features of time division multiplexing (TDM) high-speed, low-delay circuit switching and the statistical multiplexing and port sharing of X.25 packet-switching technologies. This guarantees bandwidth according to the set committed information rate (CIR) and allows bandwidth-on-demand bursts.
The frame relay network consists of frame relay switches, which usually are owned and administered by the carriers. The access connection to the frame relay network is typically provided by a Local Exchange Carrier (LEC); it can also be bundled into the frame relay provider's service. A network provider can be an LEC; a metropolitan frame relay service; an interexchange carrier (IXC); or an interstate, national, or global frame relay service.
NetWare Link/Frame Relay encapsulates data frames and routes them through the frame relay network based on the Data-Link Connection Identifier (DLCI), which identifies the local permanent virtual circuit (PVC) end point of the router. DLCIs are defined through the configuration process or learned through the NetWare Link/Frame Relay link management protocol.
A frame relay network has the following characteristics:
Using NetWare Link/Frame Relay, you can have a logical end-to-end link (a virtual private line) between communications end points. Although NetWare Link/Frame Relay appears as a dedicated private network to the user, the virtual circuits and high-speed internode trunking make it a more cost-effective service than a dedicated line service, with similar performance. It is intended primarily for high-speed, bursty data communications applications, such as WAN interconnections.
| |